I'm just curious to hear what people think. Now I've been looking at some of these manifolds and I'm just wondering. Do you find 1100 dollars to be a substantial price for a magnus or similar style intake?

If there were an intake that was of similar quality but by a less well known producer would you be willing to try it out if it were half the price of a magnus?

i would say there is always a want for a aftermarket manifold
from the few i ve made the only consideration you would have to take while building one is that there aren t as many people that could run it unless they were already at the extreme modded setup because you do away with alot of the bolt on mounting areas that the subies have

Yeah, there is definately a want for it, a few more on the market would chop the price down some I'd think.

Most people buying them are already modded pretty heavily anyways so a lack of a few things wouldnt kill the market

What sort of advantages do the aftermarket intake manifiolds provide?

Improvent in power or torque across the rev range, or perhaps just in certain parts of the rev range?

usually increased low end and definitely increased throttle response. All the designs ive seen were designed with larger "funnelesque" runners and a plenum with a volume in comparison to our engine volume. Some have suffered slightly in the top end.

The advantages of this come mainly when you are looking for more area under your power and torque curve and also for the increased throttle response it offers. Great advtanages in the world of auto-x, rally and other sports.

I figured if these became more common, almost as common as exhaust manifolds (well...maybe not tthhat common) that more people would be open to buying them

if anyone lives near philadelphia, pa there is a very well known fabricator there who if you gave him a call he may be interested in making SMIM for subys. He makes a SMIM for DSM's that are 1/2 of a magnus price and out perform them. Check out www.JMFABRICATIONS.com, he is always open to suggestions!

If your thinking of building them for a turbo subi you could do an entire kit that includes a reversed intake manifold that includes a front mount to go with it. I would guess that you could keep the turbo in its stock locations then just develop new piping from the turbo to the intercooler then up to the reversed intake. Should be fairly plug and play unless you need to relocate the ac compressor or alternator.

Just go get the USDM 2.5I manifold and make it work. No TGV's a much bigger plenum, and much better routing of the runners. It won't work with a TMIC though.


TMS

Alright, I have to be carefull how I do this untill I pay for vedor fees. We have a new intake manifold that will be available very soon. It has already gone through the flowbench testing phase and we will have one at subiefest 2 in a couple of weeks. I am sharing a booth with enduratech coilovers so stop in and check it out. This manifold will be less expensive than the other options currently on the market and should outperform them as well. I have shown pics of the prototype to a few vendors that we hope will be our distributers (we will see, and hopefully we can meet the expectations)

Keep an eye out for Brewpubeavers car as he will be the test bed. This manifold will be setup to allow it to be rotated and we will have tubing kits to match up with the major FMIC options.


Mods I hope this hasnt crossed the bounds and I appoligize in advance if it has.

Heard too many bad things about the Magnus and it's construction - I was in the market but quickly changed my mind after reading some reviews.

Heard too many bad things about the Magnus and it's construction - I was in the market but quickly changed my mind after reading some reviews.

Yeah I think it's a little pricey for a piece with questionable quality...it will be nice to see some competition on the market

has anyone heard or seen this here in the states. http://www.tracktive.co.uk/content.php?page=139

I dont even recall how I found this site

http://i44.photobucket.com/albums/f1/mmurray75/P1000395.jpg

http://i44.photobucket.com/albums/f1/mmurray75/P1000396.jpg

http://i44.photobucket.com/albums/f1/mmurray75/P1000397-1.jpg

This is what is going on my car. You need to use a FMIC and DBW throttle, and a little bit of work to use it. But I don't care I really like the way it looks, and it is an OEM part.

TMS

This is what is going on my car. You need to use a FMIC and DBW throttle, and a little bit of work to use it. But I don't care I really like the way it looks, and it is an OEM part.
Does the 2.5i have a topfeed or sidefeed injector setup?
Will any existing fuel rails bolt up?

Does the 2.5i have a topfeed or sidefeed injector setup?
Will any existing fuel rails bolt up?

Top feed.
I will be using the stock 2.5i rails converted to parallel feed. They are ~$35 side. I don't know about aftermarket ones.

TMS

Alright, I have to be carefull how I do this untill I pay for vedor fees. We have a new intake manifold that will be available very soon. It has already gone through the flowbench testing phase and we will have one at subiefest 2 in a couple of weeks. I am sharing a booth with enduratech coilovers so stop in and check it out. This manifold will be less expensive than the other options currently on the market and should outperform them as well. I have shown pics of the prototype to a few vendors that we hope will be our distributers (we will see, and hopefully we can meet the expectations)

Keep an eye out for Brewpubeavers car as he will be the test bed. This manifold will be setup to allow it to be rotated and we will have tubing kits to match up with the major FMIC options.


Mods I hope this hasnt crossed the bounds and I appoligize in advance if it has.



seems like you worded it just right, lol..

i can not wait to get this on the car

Themadscientist,

What manifold is that?

Themadscientist,

What manifold is that?


2006 USDM Impreza 2.5i single overhead cam.
There is a legacy version that uses TGV housings too. The legacy version will not bolt straight on the impreza TGV's.

TMS

2006 USDM Impreza 2.5i single overhead cam.
There is a legacy version that uses TGV housings too. The legacy version will not bolt straight on the impreza TGV's.

TMS


What exactly would I have to do to get this to work on 04 sti.

2006 USDM Impreza 2.5i single overhead cam.
There is a legacy version that uses TGV housings too. The legacy version will not bolt straight on the impreza TGV's.

TMS

Have you flowed this on a bench? I was looking around for one so I could flow it.

well, an update from the shop...we have my designed shortblock coming together (parts being manufactured) and a BC 2.71 coming to be tested. Both will get numerous cam setups and at least one non-factory manifold tested. I don't know much about this mani as I didin't design it and it is being lent to the shop for testing.
I'll be running all of the testing as a large lab and will have a report to follow.

I'm still working on my manifold design to add another variable to the testing.

Where on the same page as I just did a buy in with BC and I ordered a 2.7 kit with the goods for it as well. Inconel valves and such...

Here is my new reverse intake manifold and FMIC, numbers and more testing to follow...

http://img.photobucket.com/albums/v728/shefflk/DSCN2638.jpg

wow, those runners seem a bit long, what turbo are you running with it? I'm curious what your results will be

wow, those runners seem a bit long, what turbo are you running with it? I'm curious what your results will be

Borg Warner S200 twin scroll turbo w/ a 52lb compressor wheel and .76 exhaust AR...

Here is my new reverse intake manifold and FMIC, numbers and more testing to follow...

http://img.photobucket.com/albums/v728/shefflk/DSCN2638.jpg

I like the look of that manifold, but i see two problems.
1. The angle of the throttle body makes me think it would be hard for the left and right cylinder banks to get the same amount of flow.
2. It looks like the front runners are way longer then the rear.

I'm not trying to criticize you, but maybe you can explain why you designed it that way.

I like the look of that manifold, but i see two problems.
1. The angle of the throttle body makes me think it would be hard for the left and right cylinder banks to get the same amount of flow.
2. It looks like the front runners are way longer then the rear.

I'm not trying to criticize you, but maybe you can explain why you designed it that way.

The runners are already equal in length (the rear of the plenum sits higher than the front), a new redesigned plenum is going on the car later this week, it will be more "box" style for better air distribution to the cylinders...

The runners are already equal in length (the rear of the plenum sits higher than the front), a new redesigned plenum is going on the car later this week, it will be more "box" style for better air distribution to the cylinders...
update on the new manifold? i'm excited to see if it's even nicer than the one above!

well, an update from the shop...we have my designed shortblock coming together (parts being manufactured) and a BC 2.71 coming to be tested. Both will get numerous cam setups and at least one non-factory manifold tested. I don't know much about this mani as I didin't design it and it is being lent to the shop for testing.
I'll be running all of the testing as a large lab and will have a report to follow.

I'm still working on my manifold design to add another variable to the testing.

Initial numbers are out, public release should be soon.
Everyone will want this manifold, they will complain about price, but it PERFORMS. It's probably way overkill for 90% of the people on these forums though, including myself, but we'll see what I can do about that later.

Just go get the USDM 2.5I manifold and make it work. No TGV's a much bigger plenum, and much better routing of the runners. It won't work with a TMIC though.


TMS

You mean like this.

http://www.tunernetwork.com/forum/gallery/data/500/XX_SUBARUS_13.JPG
http://www.tunernetwork.com/forum/gallery/data/500/medium/tn_DSC02112.JPG
http://www.tunernetwork.com/forum/gallery/data/500/medium/tn_DSC02104.JPG
http://www.tunernetwork.com/forum/gallery/data/500/medium/tn_DSC02056.JPG
http://www.tunernetwork.com/forum/gallery/data/500/medium/tn_DSC02055.JPG

XX Tuning modifies these 2.5L intakes to fit either a WRX or DBW STI throttle body. They use topfeed injectors. The real gains from this manifold are the air doesn't have to slam into a wall and them break off left and right to make it's way to the heads. These manifolds actually flow so well that the air doesn't start to heat up from friction until the bend just before the heads.

update on the new manifold? i'm excited to see if it's even nicer than the one above!

yup, the new one is on the car and intial dyno runs looked really good. I had two unseated PE injectors that dont seem to want to seat properly after several attempts. I am switching over to modified stocks so we can continue the dyno testing...I'll post more when I have some more info.

that's a pretty sweet setup...

here's one that we are currently prototyping. We should have some initial power numbers within a few weeks. We are going to be selling it with a modified intercooler pipe as we moved the throttle body back a good amount. It will be able to be flipped if the customer wants..

http://img441.imageshack.us/img441/1230/dsc01633smwu9.jpg

Tomei is currently working on a new intake manifold. I saw it at the STi/EVO Hyper Meeting; it looked damn nice! Except the prize tag was something outrageous I want to say.

Picture (http://blog81.fc2.com/t/tomei/file/EJ4suro.jpg)

yup, the new one is on the car and intial dyno runs looked really good. I had two unseated PE injectors that dont seem to want to seat properly after several attempts. I am switching over to modified stocks so we can continue the dyno testing...I'll post more when I have some more info.

Any pics of the new design?

BUMP I want one!

Any pics of the new design?


it actually looks very similar on the outside. The back of the plenum is more "rounded" now...most of the new design changes were made inside of the plenum which you cant see. waiting now for the new aquamist nozzles so I can run direct port alky injection, should be here next week then can get the car on the dyno again.

sick...i want one! how much are we looking at though?

Might as well throw my sword in the fire.

ITBs under each manifold:


http://users.rcn.com/wgknestrick/Throttle%20Linkage%20001.jpg
http://users.rcn.com/wgknestrick/Throttle%20Linkage%20001.jpg

Bill

Might as well throw my sword in the fire.

ITBs under each manifold:


http://users.rcn.com/wgknestrick/Throttle%20Linkage%20001.jpg
http://users.rcn.com/wgknestrick/Throttle%20Linkage%20001.jpg

Bill

mmmm sex; impressive

hypothetically with all the work you've put into it, how much harder would it be to make that a twin turbo set up with a pair of td04's or something small like that?

Might as well throw my sword in the fire.

ITBs under each manifold:


http://users.rcn.com/wgknestrick/Throttle%20Linkage%20001.jpg
http://users.rcn.com/wgknestrick/Throttle%20Linkage%20001.jpg

Bill

looks VERY similar to the setup on the Jun Hyper Lemon GDB. Where'd you get that done, how much did it cost you, and whats the rest of your setup like?

Might as well throw my sword in the fire.

ITBs under each manifold:


http://users.rcn.com/wgknestrick/Throttle%20Linkage%20001.jpg
http://users.rcn.com/wgknestrick/Throttle%20Linkage%20001.jpg

Bill

Very unique setup, looks awesome!! Any more pics/info on the setup?

Very unique setup, looks awesome!! Any more pics/info on the setup?
Where'd you get that done, how much did it cost you, and whats the rest of your setup like?
He designed it all himself - see here (http://forums.nasioc.com/forums/showthread.php?t=1175829). Even more impressive now, eh? :) :eek:

Did anybody try this?http://www.dentsport.com/gallery/v/dsg/projects/madIntern/333.JPG.html

http://www.dentsport.com

Design is bit from APS... They will soon have a kit like that out. It is in test form right now. Im sure you can find a shot of it on their website.

Did anybody try this?http://www.dentsport.com/gallery/v/dsg/projects/madIntern/333.JPG.html

http://www.dentsport.com

that looks like a V-mount. :banana:

Design is bit from APS... They will soon have a kit like that out. It is in test form right now. Im sure you can find a shot of it on their website.

He did not copy it from APS. He saw it on the JUN Hyper Lemon car and tried to buy it, but they wouldn't sell it to him, so he made his own. ****ing cool.

Did anybody try this?http://www.dentsport.com/gallery/v/dsg/projects/madIntern/333.JPG.html

http://www.dentsport.com

Dentsport is a top notch shop in every aspect and incredible fabricators too. That manifold pictured above, however, I am not crazy about the design at all. They have done incredible designs on other projects, but this is not one of them (IMO). They also have a new Subaru design IIRC out.

I spent about 100hrs researching intake manifold design before I even started my project above so I have acquired a little knowledge on the subject. I do not claim to be an expert, but I feel I have put more time than most into this subject. I am sure there are things that DS does not like with my design, but there are different approaches to everything. That manifold may make good HP too, but from what I've read, I think there are things that could be improved.

I wish I had my exact calculations still ref exact #s, so bear with me.

First, the DS runner length is too short. Theirs looks to be about 10" (including TGVs, head port, and 3" runner length elbow) This shifts the 3rd order resonance (what most people use to design runners) power band up too far in the RPMs (for me). From my calculations, you want about 8-8.5" CL distance (not string measured) of runner on top of the TGVs. This gives a total runner length around 14-14.5" (valve to port) which puts tuned RPMs at 5500 (3rd order) with (4th) and (5th) at lower spool RPMs 3K & 4K.

This runner effect (Helmholtz resonance) is not to be underestimated as it increases the charge air pressure density (& hp) by a significant amount in these RPMs. This is why you cannot just design for optimum flow, as the cylinders only need "bites" of air and you must provide the most dense air at the right time.

This is a very good link on the subject:
http://www.grapeaperacing.com/GrapeApeRacing/tech/inductionsystems.pdf

2nd, The plenum volume is tiny. OEM manifold tiny. This will also hurt top end power because there is not a reserve of air to supply the engine on intake stroke. The plenum acts as an air capacitor to supply the engine quickly with air that is just above the runner. Subaru engines also require BIG plenums with respect to other cars because both cylinders on each bank fire simultaneously. This puts a big, momentary demand of air on separated plenums (like mine, JUNs, & DS). There is a point of diminishing returns on plenum size however and the larger the plenum the less throttle response because your throttled volume increases.

I have each of my plenums around 2.5l for a total plenum volume of 5l for a 2.5l engine. Having ITBs under the plenums allows me to run very large plenums without any of the negative affects because my throttled volume is still extremely small (<.25l) under the ITBs.

One area that I did not design very well is my plenum "ceiling" face. A flat "ceiling" face (face opposite runner port entries) reflects the sound waves better back down the runners and thus has a greater tunned effect. My round plenums are cheap however, and you must ultimately be able to build your nice manifold out of easily acquirable materials.

I would also put velocity stacks in any manifold as they really improve airflow.
www.velocityofsound.com is a great place to get these in many sizes.

http://users.rcn.com/wgknestrick/0190.jpg

This is the best manifold design I have seen by far on a Suby (cosiecovert) and the results prove this. This guy really knows what he is doing (car runs 9s).

Things that are great about this:

1. Runner length He looks to be running around 12" or so, but revs high enough to justify it (I don't)
2. High injector location. This really helps increase HP in high RPM because it gives fuel more time to atomize in the high velocity air. F1 cars have injectors outside of the intake ports FYI (kind of a fire hazard though)
3. Big plenum volume

Only problem is that the design requires extensive modification and time to make it all work...I was looking for something more "bolt on" that doesnt require modding of any other parts (and thats what I got)

Only problem is that the design requires extensive modification and time to make it all work...I was looking for something more "bolt on" that doesnt require modding of any other parts (and thats what I got)

You cannot have anything good without putting the time and effort into it. Keep your car stock or shell out $1200 for Magnus's manifold. It's the best you are going to get, and you won't be able to build one like it for much under $700 doing it yourself. Flanges and tubing are pretty expensive now.

$30 x 4 for bends
$30 x 4 for velocity stacks
$300 TIG welding
$200 for flanges.

This stuff adds up really quick and you might as well buy it from them as it works as soon at it gets to your door.

Dentsport is a top notch shop in every aspect and incredible fabricators too. That manifold pictured above, however, I am not crazy about the design at all. They have done incredible designs on other projects, but this is not one of them (IMO). They also have a new Subaru design IIRC out.

One area that I did not design very well is my plenum "ceiling" face. A flat "ceiling" face (face opposite runner port entries) reflects the sound waves better back down the runners and thus has a greater tunned effect.



Bill,

Could not agree more with your comments on the Dentsport manifold. It just makes no sense??

By flat ceiling face on the plenum, do you mean something like this; :-)

http://i25.photobucket.com/albums/c69/skakavas/SKengbaylh-1.jpg

http://i25.photobucket.com/albums/c69/skakavas/Rexebay.jpg

Cheers,

Stephen

$30 x 4 for bends
$30 x 4 for velocity stacks
$300 TIG welding
$200 for flanges.

This stuff adds up really quick and you might as well buy it from them as it works as soon at it gets to your door.

if you really do it yourself you can use tubing, sheet metal, some labor and then it will cost a looooot less than 700

if you really do it yourself you can use tubing, sheet metal, some labor and then it will cost a looooot less than 700

Trust me, the stuff adds up very quickly. I have the finished manifolds to prove it and I even got a lot of freebees. That estimate is pretty accurate for someone doing it themselves with average garage tools, and help from outside on welding/machining. Most people cannot just make good flanges out stock plate on their own. Machinist really helps here.

Bill,

Could not agree more with your comments on the Dentsport manifold. It just makes no sense??

By flat ceiling face on the plenum, do you mean something like this; :-)

http://i25.photobucket.com/albums/c69/skakavas/SKengbaylh-1.jpg

http://i25.photobucket.com/albums/c69/skakavas/Rexebay.jpg

Cheers,

Stephen

You get this thing running yet or are you still fighting 100s of small problems like me? I'd love to see some video of it idling and thru the gears.

Bill

You get this thing running yet or are you still fighting 100s of small problems like me? I'd love to see some video of it idling and thru the gears.

Bill

I had to wait for months to get the custom mirrored throttle bodies made (not in pics) as the machinist buggerised around. Throttle cables, vacuum block, remote oil res etc etc were all finished yesterday actually. It is back to the shop to get the real motor fitted, along with a new harness and the balance of the fuel system before it is fired up. Happy to share some video when the time comes.

Cheers,

Stephen

Trust me, the stuff adds up very quickly. I have the finished manifolds to prove it and I even got a lot of freebees. That estimate is pretty accurate for someone doing it themselves with average garage tools, and help from outside on welding/machining. Most people cannot just make good flanges out stock plate on their own. Machinist really helps here.


I said "if you really do it yourself", meaning you weld it yourself and make everything from scratch. its a lot cheaper than you'd think. of course you do need some tools that the common person does not have, but thats usually common of the DIYer. If you get any help that requires paying someone labor costs then of course its going to cost you more.

That V-mount Dentsport WRX looks butchered.

I really like the looks of that center split intercooler and the velocity stack on the end of the runner.

Nice job welding that aluminum. The Densport looks more like a solder or "allumaloy" job.

I see the outlet of the coolent crossover pipe but where is the radiator?

brad

I see the outlet of the coolent crossover pipe but where is the radiator?
brad

This might give you a better idea of the radiator setup. Plenums are made from 4mm aluminium plate, pipe and donuts, welded inside and out. Welds are then finished back and then re-welded inside and out before finishing back to final surface.

http://i25.photobucket.com/albums/c69/skakavas/SKengbayston.jpg

http://i25.photobucket.com/albums/c69/skakavas/askradrear.jpg

http://i25.photobucket.com/albums/c69/skakavas/aaskunderfromlh.jpg

http://i25.photobucket.com/albums/c69/skakavas/aaskdownfront.jpg

This was the other Dentsport manifold that I was talking about. I think it is much better than their first attempt, but the runners are really/really short. Everything I have read states that it is much better to have runners that are too long rather than too short. This is because with the longer runners, you will at least cross thru the tuned RPMs of the manifold, where the short runners you never reach that RPM with the engine.

I am sure there is a point where the straight, short runners just start to out flow/perform the "tuned" design just based on shear volume efficiency. The short runners will have many high order resonances that you will cross thru, but the pressure waves will be much smaller (think of a decaying echo). Referencing other manifolds for different makes, not too many companies make manifolds with runners this short. They are mostly around the 5"-10" runner length (head to runner port). Only manifolds I've seen like this are on Porsche's (aftermarket) and I think it is mostly for packaging reasons, not performance.

http://www.dentsport.com/gallery/d/6782-2/DCP_1028.JPG

stop whoring pics and get that thing running Stephen!!!

From some of the posts I've read elsewhere I think even the Dentsport guys will admit it might not be the optimum design. They're experimenting and will find out how it works when it hits the dyno. At least, that's impression I've gotten reading about their time trial car build.

Pat

The radiator setup seems pointlessly large and in my opinion should not be at the frontmost part of the bumper like that... Can you say road debris? That thing will be don within the 1st 10k miles... just my 2cents

The radiator setup seems pointlessly large and in my opinion should not be at the frontmost part of the bumper like that... Can you say road debris? That thing will be don within the 1st 10k miles... just my 2cents

Try and do 20 laps of a race track in a 600hp GC8 with a FMIC and radiator in the std location and get back to me.........

Before that location and configuration was chosen we measured the velocity pressure profile of the car at speed. I originally was hoping to mount the radiator in the boot and duct air up through where the back seat nomally sits with a discharge out the boot, but for a number of reasons testing showed it was never going to work. Is it subject to damage more than the stock location, sure, but the car is not a daily driver.

The radiator is only 19mm thick with a particular fin pitch (for a few reasons) and accordingly combined with the intended use which includes circuit racing needs to be that size. That what you "think" and what we calculated is required are different, does not suprise me.

Cheers,

SK

PS: How long was yours off the road Jacob? :-)

stop whoring pics and get that thing running Stephen!!!
x2,to much bling aswell.But shouldn't be to far away?

Kris

[QUOTE=wgknestrick;17843196]This was the other Dentsport manifold that I was talking about. QUOTE]

I still don't get it. In addition to your h/r points wrt tract length, why use a dual plenum design with a single throttle body? It seems to me to be taking to worst features of most twin plenum designs and concatenating them with the worst features of most large single plenum designs????

x2,to much bling aswell.But shouldn't be to far away?

Bling is under the bonnet out of sight.

http://i25.photobucket.com/albums/c69/skakavas/SkRex001.jpg

Seemingly SKC got her panties in a bunch when someone states an opinion. I dont do your roundy round auto x anyway, so you dont have to worry about gettin run over with my 500 hp 2.0L. FYI - the better design would have put it in the trunk where you dont have to worry about destroying your oversized radiator. Take a look at the drift subarus and you tell me they dont spend their time at redline taking a beating and a half... Im saying nothing but enjoy your radiators short life. After it gets cracked wide open youll have to fab another, and it will probably go in the trunk...

Thanks for coming and adding nothing more than typical NASIOC attitude to what was a semi technical discussion.

You are the one that remarked the radiator was pointlessly large and started this whole debate for no reason. This thread is about INTAKE MANIFOLDS, not radiators. This is why nobody can find information on Nasioc anymore. Threads start on topic, then 2 pages later Efight breaks out.

Please stay on subject.

PS. I do not think you are qualified to critique SKC's setup in any way until you do at least 1/4 of the work he put into that car. Back to intake manifolds

Seemingly SKC got her panties in a bunch when someone states an opinion.


Not at all. I welcome the informed opinions of others. I stated the boot was my 1st choice, but real testing and measurement of the velocity pressure profile showed on a gc8 the only way to get air to the boot was through a large duct in the roof or from massive ducts in the rear doors. For the classes I am interested in competing in, that is not tenable. The drift guys generally draw from the doors. Whilst that works for them, their use is completely different from mine. Firstly the cars only do one or two laps at a time (not 20) and for them, a front mounted radiator is not often perpendicular to the direction of travel.

Anyway, if you want to discuss further, PM me, otherwise.... back to intakes.

Stephen

better watch out for srREXed's 500hp 2L Stephen! lol

http://users.rcn.com/wgknestrick/0190.jpg

This is the best manifold design I have seen by far on a Suby (cosiecovert) and the results prove this. This guy really knows what he is doing (car runs 9s).

Things that are great about this:

1. Runner length He looks to be running around 12" or so, but revs high enough to justify it (I don't)
2. High injector location. This really helps increase HP in high RPM because it gives fuel more time to atomize in the high velocity air. F1 cars have injectors outside of the intake ports FYI (kind of a fire hazard though)
3. Big plenum volume

does anyone have dyno sheets for this car?

http://forums.nasioc.com/forums/showthread.php?t=1078212

http://www.andyforrestperformance.co.uk/index2.html

Im glad to see everyone can judge my opinion... Just dont be pissed off because I can have one that differs than all of yours. Maybe they do things a bit different in the land down under. NASIOC: North American Subaru Owner's Association. Another thing, you are right, I dont drive in circles... I run straight lines. Thats a big difference in interest to your conversations. Tell me this about your manifolds, is it going to make a big enough difference on your 320hp street cars for the 5 hundo you all are going to dish out to buy one of these? Or can you weld and make one yourself for less than 100 bucks worth of aluminum stock and piping? Just a rhetorical question... I dont expect a reply from anyone. Just know that because it says scooby newbie doesnt mean I was born into a subaru yesterday, and then decided to post a bunch of pictures of intake manifolds that dont belong to me. SKC... didnt mean anything by the panties thing, just breakin balls.


Peace

Andrew

Good evening guys!

Andrew, I think almost any after market manifold is a waste of time for a 320hp street car.

In terms of cost, the real killer is not the pipe and plate etc. It is the development time and labour involved that is the killer.

Cheers,

Stephen

Im glad to see everyone can judge my opinion... Just dont be pissed off because I can have one that differs than all of yours. Maybe they do things a bit different in the land down under. NASIOC: North American Subaru Owner's Association. Another thing, you are right, I dont drive in circles... I run straight lines. Thats a big difference in interest to your conversations. Tell me this about your manifolds, is it going to make a big enough difference on your 320hp street cars for the 5 hundo you all are going to dish out to buy one of these? Or can you weld and make one yourself for less than 100 bucks worth of aluminum stock and piping? Just a rhetorical question... I dont expect a reply from anyone. Just know that because it says scooby newbie doesnt mean I was born into a subaru yesterday, and then decided to post a bunch of pictures of intake manifolds that dont belong to me. SKC... didnt mean anything by the panties thing, just breakin balls.


Peace

Andrew

Good evening guys!


thanks for the entertainment :lol:

ps. NASIOC stands for North American Subaru Impreza Owners Club, and whats your point anyway?

I agree stephen, thats why I dont understand half the people in this forum. No bother. As far as improvement in flow how much of a difference in a 500 HP 2L do you think a manifold would make?

http://forums.nasioc.com/forums/showthread.php?t=1078212

http://www.andyforrestperformance.co.uk/index2.html

thanks for the links, but i still couldnt find any dyno sheets :(

One thing I noticed is that for a group of people that claim to be so into autox most people dont want to a more even powerband. They want to keep their top end as high as possible.

Most of the aftermarket intakes ive seen are single plane intakes that, generally speaking, usually create opportunity for top end but do not help much in the low end spectrum. A manifold could be created that would help low end but of course you're going to lose some top end as well.

To shift the powerband to the left in development id say the runners on a manifold should be shorter... Doesnt apply to me.

To shift the powerband to the left in development id say the runners on a manifold should be shorter...
Are you sure about that? I realize I'm comparing apples and oranges here, but in the 5.0L Mustang world if you want low end torque you go with long runners (such as the factory 5.0L HO intake manifold), and if you want top end power you go with short runners.

Pat

low end torque you want skinny longer runners and a larger plenum(s) will also help. high end should be wider shorter runners

Are you sure about that? I realize I'm comparing apples and oranges here, but in the 5.0L Mustang world if you want low end torque you go with long runners (such as the factory 5.0L HO intake manifold), and if you want top end power you go with short runners.

Pat

No, you are right, and the physics are the same no matter what engine you are dealing with. It all works on resonance. Long runners resonate at a lower frequency (RPM) and shorter at higher (RPM). Just like strings on guitar.

My bad

I would think that shorter runners would be important on a turbo'd car though...if all the piping of most front-mount intercooler kits lead to more lag, wouldn't longer runners do the same, because it's still more piping to pressurize?

made a small diameter long runner manifold for kienans 2.0 at all aspects yes indeed it lowered the rpm band by almost 1500 rpms

^^^No pics= no manifold! ;)

Jay

here ya go
http://i84.photobucket.com/albums/k22/Vmiz/ttcar.jpg
forgot i was on nasioc
this was one of the designs
wasn t made to be pretty it was for testing
next will be a cleaner model

forgot i was on nasioc

Hey now, you can thank all the online experts that misinform the rest of us. BTW, since this is Nasioc, I think we need to see a dyno chart too. ;) Oh, and keep us posted on the cleaned-up final product!

Looks pretty good. What kind of volume did you end up with in that center section?
here ya go
http://i84.photobucket.com/albums/k22/Vmiz/ttcar.jpg
forgot i was on nasioc
this was one of the designs
wasn t made to be pretty it was for testing
next will be a cleaner model


A dyno sheet would be pretty nice too.....being nasioc and all. :lol:

Jay Storm

Guess I'll post a pic of ours too then....
http://thumb19.webshots.net/t/36/37/0/9/93/2518009930094569859dwXQks_th.jpg (http://rides.webshots.com/photo/2518009930094569859dwXQks)
SVT Mustang throttle body, Ford 30lb/hr injectors and adjustable FPR. (non-turbo application). Fabwork and design credit to Irish Mikes.

Jay Storm

oh, that's original! any links to more info about the rest of the build? what sort of power did you end up with?

I think I've seen yours before, Jay, but I'm getting the red X in your post above.

they were already posted months ago in the power section under one of the all aspects twin turbo car thread
the car ended up with 413 on a jdm 2.0

I read several places that many turbo cars can work very well up top and have a wide power band with a longer runner intake because at high RPM's once the turbo is at full song you have its assistance in forcing air into the cylinders (unlike an NA car).

yes depending on runner diameter that would work
i used a smaller diameter runner to help with air speed to help it spool sooner
therefore instead of a steady climb it reach 413 and stayed straight across
we were nt looking for more rpms just to help in the lower end
i am going to make a larger runner one since he is going 2.5 instead of 2.0 on his next motor

Vacuum take off, water injection ports and custom throttle bodies and throttle cables added.

http://i25.photobucket.com/albums/c69/skakavas/finishedbaylhm.jpg

what's with the top mount with a front mount?

thats no intercooler up there

Based on the -10AN or -12AN fitting on the end that would appear to be an oil cooler.

I dig the turbo-to-intercooler piping going under the accessory belt. :cool:

Storm, nice manifold. That to me seems the most useful out of all of the manifolds ive seen yet. 30lb injectors... im an american car nut but I mostly work with carb cars. How many ccs is that? How much for the throttle body?

Storm, nice manifold. That to me seems the most useful out of all of the manifolds ive seen yet. 30lb injectors... im an american car nut but I mostly work with carb cars. How many ccs is that? How much for the throttle body?The injectors work out to be 291.4 cc/min. We're loafing the pump along at just 34psi for our needs. The TB was sourced cheap....I don't remember exactly what the cost was. It took some creative engineering to get the TPS to play nice with the OEM Subaru stuff. When we looked into it, we were sold on it making +30hp at 9000rpm. We won't ever rev that high...but if we gain a portion of that within our powerband, we get a net gain. That was the plan and so far it's worked out well. We haven't gotten anywhere near the potential out of the setup yet....being poor sucks.:lol:

Jay Storm

Bill and Patrick are spot on the money, it is an oil cooler.


Bill, this is what I ended up doing for throttle actuation;

http://i25.photobucket.com/albums/c69/skakavas/Linkagefinishedm.jpg

I considered a linkage arrangement, but this seemed to be a simpler more bind free solution. I reckon it would work really well with a ITB solution. All I need is the design :-)

I want to work out the ITB bugs first. My linkage is working pretty well right now. Leaking is another thing though, but we are getting off topic here.

How are you detecting the leakage? Can you measure it? Any thoughts on a perspective solution? If too off-topic, PM me.

SK

How are you detecting the leakage? Can you measure it? Any thoughts on a perspective solution? If too off-topic, PM me.

SK

Check out my thread here for status of project:
http://forums.nasioc.com/forums/showthread.php?t=1175829

Has anyone thought of using a merge collector in reverse to feed the intake runners?

It wouldn't really leave you with much of a plenum but it seems like it would do really well to distribute the air evenly without many physical obstacles.

Has anyone thought of using a merge collector in reverse to feed the intake runners?

It wouldn't really leave you with much of a plenum but it seems like it would do really well to distribute the air evenly without many physical obstacles.


Whilst it sounds seductive in a static flow condition, the problem is that due to the valve timing you actually get flow reversion back into the plenum. If you used a merge collector, the reversion from one cylinder would interfere with the flow in the merge collector wrt the balance of the cylinders.

What if you tuned the lengths of the runners to account for this at a certain RPM range. Might be a good but elaborate option for a drag race motor.

yeah, like pulse tuning...aka helmhotlz resonance frequency tuning... ;)
already have the numbers done...just need time and money to do it...now that school is nearly done, both should be coming :D

yeah, like pulse tuning...aka helmhotlz resonance frequency tuning... ;)
already have the numbers done...just need time and money to do it...now that school is nearly done, both should be coming :D

Intake Manifold that can double as a speaker box :)

Toyota's Corolla has had this type of manifold for a few years now....Maybe others have it too?

Jay Storm

I see a lot of these manifolds dont have provisions for the Coolant Header Tank. What do you guys do with them?

Vacuum take off, water injection ports and custom throttle bodies and throttle cables added.

http://i25.photobucket.com/albums/c69/skakavas/finishedbaylhm.jpg

wow.....now thats just crazzy :cool:

is the throttle responce worth it?

I see a lot of these manifolds dont have provisions for the Coolant Header Tank. What do you guys do with them?
oooh, good question!

you mean that little coolant container for the turbo?
i would guess these turbos are oil cooled only

also you can just extend the hoses and mount it over on the innerskirt

you mean that little coolant container for the turbo?
i would guess these turbos are oil cooled only
its a GT series turbo so its oil and water.
U can mount the water header tank anywere u want..but it usely better to mount it alittle higher than the turbo for better water flow.

Kris

saw this in another thread....
I like the reservoirs and this setup , it's .... well different!
http://photos.imageevent.com/speedywrx/kawshoot/sickscoob.jpg

I see a lot of these manifolds dont have provisions for the Coolant Header Tank. What do you guys do with them?

You mean like these;

http://i25.photobucket.com/albums/c69/skakavas/closeupbottlesm.jpg

http://youtube.com/watch?v=_XWtY0rme14

I'd love to get some info on this car, sorry if it's a repost.

wow.....now thats just crazzy :cool:

is the throttle responce worth it?

In terms of throttle response, excluding consideration of the flow benefits from the removal of so many bends that existed with the more traditional FMIC routing, the compressor to throttle body distance is now less than 1/3 of what it was. Add the benefits of not having the peak power rpm imposed by the design limits of the std inlet manifold and throttle body and I believe it is more than worth it.

heres my feeble attempt, seems to work well though.
http://homepage.mac.com/watsonj0/.Pictures/Photo%20Album%20Pictures/2007-01-31%2017.27.39%20-0800/Image-424622BBB19311DB.jpg
http://homepage.mac.com/watsonj0/.Pictures/Photo%20Album%20Pictures/2007-03-15%2014.29.09%20-0700/Image-1AB9B310D33C11DB.jpg
5L volume in plenum

Why 2 coolant tanks? Is the piping 4" all the way to the i/c? Is the plenum 1 piece?

heres my feeble attempt, seems to work well though.
http://homepage.mac.com/watsonj0/.Pictures/Photo%20Album%20Pictures/2007-01-31%2017.27.39%20-0800/Image-424622BBB19311DB.jpg
http://homepage.mac.com/watsonj0/.Pictures/Photo%20Album%20Pictures/2007-03-15%2014.29.09%20-0700/Image-1AB9B310D33C11DB.jpg
5L volume in plenum

Any more pics on this setup?

^^^ any dyno sheets as well?

^^^^

That should work, not because I'm building one of approximately the same dimensions, but it should work well.

Ill post some more pics, no dyno here on St. lucia though.
run 10.1 so shes' fairly quick.

sweet, ive seen vids of your car before, its a beast. H
ey your not the poor guy that crashed while being towed by any chance?

ps. whats the reasoning behind the recess in the plenum? Is that to clear the alternator or for another reason?

are those ported stock runners you used?

recess was for clearence, yes I used ported stock runners and the car was the one towed and crashed

just curious... what kind of welder are you guys using?

I'm in the market for a new one (mine can't use argon :()

heres my feeble attempt, seems to work well though.
http://homepage.mac.com/watsonj0/.Pictures/Photo%20Album%20Pictures/2007-01-31%2017.27.39%20-0800/Image-424622BBB19311DB.jpg
http://homepage.mac.com/watsonj0/.Pictures/Photo%20Album%20Pictures/2007-03-15%2014.29.09%20-0700/Image-1AB9B310D33C11DB.jpg
5L volume in plenum

So what are the ridges/fins for?

So what are the ridges/fins for?

Im guessing for rigidity.

Nitrous backfire can expand split the intake manifold :)
Belive me I know.
Ridges are to give strength the bottom is 1/4" ali plate

random bump for one of my favorite newer threads! any new designs?

Found this one while surfing around the other day...

http://watop.com.tw/images/intake01.gif (http://watop.com.tw/e/intake.htm)

Is there anything on the market yet? Seems to be everyone is still on R&D stage... I need one soon!

Click on the photo in the post above ^^^^

http://users.rcn.com/wgknestrick/RUNNER%20LENGTH%20CALCULATION.jpg

http://users.rcn.com/wgknestrick/RUNNER%20LENGTH%20CALCULATION.jpg

I put this together when I made my manifold(s). Basically this is a 2.5L STI engine with stock STI cams. Runner ID = 2.0" (which is pretty close to optimal). The resonance frequencies are graphed out with respect to order from the 3rd order on. Other Subaru engines (2.0l or wild cams / both inputs) would be very similar to this.

You can chart your runner length across the graph, and every place an order crosses it, you will get a coresponding increase in intake pressure (ie + HP). The lower the order, the greater this effect will be.

I graphed both stock and my (what I think is optimal for both packaging & performance) lengths.

Bill

That's some nice information there Bill, the problem I see is that you have increased the separation between the 3rd and 4th order so instead of being 4250-5500rpm you have moved it to 5000-6500rpm.

The advantage of your intake is that you managed to pickup the 7th order where the stock intake misses out.

I'm curious how you worked out the info to create this chart. I'd like to take a look at something like this to help me design an intake manifold for my 2.65 motor. Looks like there could be a bit to gain here...

I have the same charts done in several ways...I'm curious as to what values and constants he used.

Found this one while surfing around the other day...

http://watop.com.tw/images/intake01.gif (http://watop.com.tw/e/intake.htm)

I look @ that.... I didn't see any price...

http://users.rcn.com/wgknestrick/RUNNER%20LENGTH%20CALCULATION.jpg

http://users.rcn.com/wgknestrick/RUNNER%20LENGTH%20CALCULATION.jpg
...

what the hell are TGV's?? :p ...;)

I look @ that.... I didn't see any price...

You need to email them for a quote, they are hand built to order.
There is a lot of info they send out but the upshot is they want $1800 US to make one and ship it to Australia.

If you order more then they will of course drop the price quite a bit...

Would you not want to include the TGV bodies along with the calculations since they account for a portion of the runner length. I think this would make quite a difference in the plots.

-Michael

Would you not want to include the TGV bodies along with the calculations since they account for a portion of the runner length. I think this would make quite a difference in the plots.

-Michael

Also port size and length? Everything before the intake valve will have some effect.

TMS

also for the reflective value charts, you should measure from the back of the valve for a more accurate length. TGV's are quite a change in length.

Also port size and length? Everything before the intake valve will have some effect.

TMS

All of this was accounted for guys.;)

The graphs are meant to be an end user, simple thing. Showing the entire runner length means very little if you don't have all of the other measurements. There is roughly about 7.25" of effective runner distance that would be additional to the lengths in my graph to account for valve to top of the head and for TGV heights.

In my experience one of the most critical parts of a manifold design is a correct taper from the runner to the head. This of course provided some idiot hasn't screwed things up by "port matching". I've seen a few cases where read on the interweb that they should enlarge the manifold to match the size of the port. Unfortunately the dyno later showed anywhere from 5-15hp lost... The manifold to head interface should go from a smaller manifold opening to a larger port opening.

-Michael

The manifold to head interface should go from a smaller manifold opening to a larger port opening.
here's the fun part....do you know why? and under what circumstances?
why would one have a hp gain from making a flow loss?

also for the taper, 2* is a good rule of thumb...for restrictors opening up though 7* is a good rule of thumb...so think about that

The whole taper debate kills me.

Taper is just a rough variable into the ideal shape of a port transition and most people know this to be a full exponential DIA velocity stack. Taper mearly approximates this ideal shape, but the debate on weather to use 3 deg or 5 deg or Xdeg kills me. There is no best taper angle because there is no angle, just continuously increasing curvature into the port.

well, seeing SAE tests and varifying myself for fsae, we have found, as have other FSAE teams, 7* to be the best for coming off of a restrictor...also the 2* rule of thumb is what I had found...yes if you have enough distance to run the directed stream over you can continually open it...of course you then get into velocity and point of seperation...so really nothing is fixed...
hence why I say rule of thumb...it won't be far from that.

here's the fun part....do you know why? and under what circumstances?
why would one have a hp gain from making a flow loss?


Yes I know why. To be more technically correct would lose torque from a reduction in flow if your assumption were correct which it is not.

As for your taper figures they're a good "theoretical" starting point but anyone who has actually designed or worked on a manifold like this will quickly agree that they are only that.

-Michael

[quote=Homemade WRX;18373406]here's the fun part....do you know why? and under what circumstances?
why would one have a hp gain from making a flow loss?

It works as an anti reversion step I believe. I've seen headers made with steps exiting the ports, Its helps keep the pulses flowing in one direction.

[quote=Homemade WRX;18373406]here's the fun part....do you know why? and under what circumstances?
why would one have a hp gain from making a flow loss?

It works as an anti reversion step I believe. I've seen headers made with steps exiting the ports, Its helps keep the pulses flowing in one direction.

you are correct...also one reason why cup teams and other major racing league teams will flow there ports in reverse...

Yes I know why. To be more technically correct would lose torque from a reduction in flow if your assumption were correct which it is not.
are you serious...and what is hp in comparison to torque? oh yeah a relationship through rpm...way to nit pick ;)
what was my assumption? if by having a flow loss you are saying I'm wrong. Do I need to go back to the engines lab I ran at school and verify values on the flowbench for you? maybe just show you pipe exit flow values from a fluid mechanics book?

As for your taper figures they're a good "theoretical" starting point but anyone who has actually designed or worked on a manifold like this will quickly agree that they are only that.
as I said a rule of thumb (also known as a ballpark and starting point). Not the best degree/taper in the world. A ballpark value to start with.
As someone who has designed made and verified manifolds you would be wrong in this bold statement again. I and other fsae teams have varified between 6,7 and 8 degree tapers and found that the 7* value to flow the best coming off of a restrictor...now collecting back down is an entire different value. That isn't the biggest concern in making power in our motors though.

Please guys, lets keep the nasioc-isms in other threads here.

Here's some shots of the new Tomei setup (sorry I don't have a scanner so i had to use my phone). If some of the terms are wrong its b/c this stuff is a bit new to me so please feel free to correct. The Tomei setup has 4 ITB and use a special linkage to correctly use them. The inlet for the intercooler piping goes under the manifold and comes out just to the right (from front view) of the alternator. The kit is supposed to be around $6k US according to the magazine. We all know Tomei is known for their quality and performance so I'm sure this kit will be amazing. Well on to the pics.

http://i4.photobucket.com/albums/y144/digitalboy40/Cars/TS380076.jpg

http://i4.photobucket.com/albums/y144/digitalboy40/Cars/TS380078.jpg

http://i4.photobucket.com/albums/y144/digitalboy40/Cars/TS380077.jpg

http://i4.photobucket.com/albums/y144/digitalboy40/Cars/TS380079.jpg

There is a technical and legitimate reason for moving the discussion over to torque. I quoted the horsepower lost on one setup I retuned because it's easy for people to identify with and was a loss of peak horsepower. It's not to nitpick what you're trying to say - just to continue the discussion in a more technically accurate fashion.

Even at maximum lift my customer's "port matched" intake manifold had less than 2cfm difference from the factory piece and that was pulling a full 28". In other words that extra few mm of material is not the restriction - the head is. I also did reverse the two and there was a significant difference in flow. The customer was paying to use the bench so I don't have those figures anymore but if memory serves it was about 30cfm difference.

With regard to the tapers you seem to be confused. We're talking about an intake manifold not a restrictor. I've done a considerable amount of research on restrictor designs and I can say 100% that the ideal restrictor design is not the ideal intake manifold design. On the intake manifolds we have no only the packaging constraints but cost/benefit.

I wanted to bring up the taper issue so those doing their own home R&D would have an important point to consider. I've invested a fair amount of time in dynomation figuring these things out. I'm trying not to sound insulting so don't take it that way. This is a WRX intake manifold not a FSAE project someone did in school.

-Michael

are you serious...and what is hp in comparison to torque? oh yeah a relationship through rpm...way to nit pick ;)
what was my assumption? if by having a flow loss you are saying I'm wrong. Do I need to go back to the engines lab I ran at school and verify values on the flowbench for you? maybe just show you pipe exit flow values from a fluid mechanics book?


as I said a rule of thumb (also known as a ballpark and starting point). Not the best degree/taper in the world. A ballpark value to start with.
As someone who has designed made and verified manifolds you would be wrong in this bold statement again. I and other fsae teams have varified between 6,7 and 8 degree tapers and found that the 7* value to flow the best coming off of a restrictor...now collecting back down is an entire different value. That isn't the biggest concern in making power in our motors though.

There is a technical and legitimate reason for moving the discussion over to torque. I quoted the horsepower lost on one setup I retuned because it's easy for people to identify with and was a loss of peak horsepower. It's not to nitpick what you're trying to say - just to continue the discussion in a more technically accurate fashion.

Even at maximum lift my customer's "port matched" intake manifold had less than 2cfm difference from the factory piece and that was pulling a full 28". In other words that extra few mm of material is not the restriction - the head is. I also did reverse the two and there was a significant difference in flow. The customer was paying to use the bench so I don't have those figures anymore but if memory serves it was about 30cfm difference.

With regard to the tapers you seem to be confused. We're talking about an intake manifold not a restrictor. I've done a considerable amount of research on restrictor designs and I can say 100% that the ideal restrictor design is not the ideal intake manifold design. On the intake manifolds we have no only the packaging constraints but cost/benefit.

I wanted to bring up the taper issue so those doing their own home R&D would have an important point to consider. I've invested a fair amount of time in dynomation figuring these things out. I'm trying not to sound insulting so don't take it that way. This is a WRX intake manifold not a FSAE project someone did in school.

-Michael

fair enough and in this given case of flow differences I would have to agree completely with keeping the "anti-reversion" step with a minimal peak flow loss.
Yes, I know it isn't a restrictor nor a FSAE project design debate. Just sharing some knowledge and tested specs that I have found to work well...we have tested (2-5*) and have used a 3* taper over our 18" runner length too..but once again difference motor and drastically different velocity.

Great thread!

wgknestrick: Huge thanks for the time you spent on the graph, very informative.

Question:


anyone measured the volume of the plenum on the current stock Subi manifold?

any measurment on the diameter of the runners on the stock Subi manifold? (undertand they vary a bit, but average diameter would work)


Bishop333

The plenum volume is different according to the year. I used an STi v4 as a basis for my prototype. I will have to dig up the numbers. As for the runner size they are really restrictive at the tops and are fairly small. I cut one up into a lot of pieces so I will see if I can find a few and measure them for you. If memory serves it's about equivalent to a 1.5"ID pipe.

Sorry I don't have any numbers to give you right here but things have been really busy...

-Michael

How's this for an "aftermarket" intake manifold ... saw this one this weekend :)

http://i71.photobucket.com/albums/i152/illnastyimpreza/100_0774.jpg

How's this for an "aftermarket" intake manifold ... saw this one this weekend :)

http://i71.photobucket.com/albums/i152/illnastyimpreza/100_0774.jpg

that thing looks like a pair of lungs!

nice setup

Anyone notice what's going on over/by the dogbone in ^that^ pic?

Looks like Twin scroll goodness...

How's this for an "aftermarket" intake manifold ... saw this one this weekend :)

http://i71.photobucket.com/albums/i152/illnastyimpreza/100_0774.jpg

quite similar to how I wanted to do mine, just not quite so assymetrical and not such short runners...

That's the Dentsport Rev2 that we mentioned earlier in the thread.

Heres a Custom one:

http://ignitionmagazine.co.nz/content/coverage/45/photos/_MG_5877.jpg

This is the fastest street legal subaru in New Zealand

This is a very interesting read, and being probably one of the majority of people that are interested in this idea but are only making modest power, this intake mani below is probably the best for the moderately built cars?

Sorry , I do not mean to dumb this back down.

You mean like this.

http://www.tunernetwork.com/forum/gallery/data/500/XX_SUBARUS_13.JPG
http://www.tunernetwork.com/forum/gallery/data/500/medium/tn_DSC02112.JPG
http://www.tunernetwork.com/forum/gallery/data/500/medium/tn_DSC02104.JPG
http://www.tunernetwork.com/forum/gallery/data/500/medium/tn_DSC02056.JPG
http://www.tunernetwork.com/forum/gallery/data/500/medium/tn_DSC02055.JPG

XX Tuning modifies these 2.5L intakes to fit either a WRX or DBW STI throttle body. They use topfeed injectors. The real gains from this manifold are the air doesn't have to slam into a wall and them break off left and right to make it's way to the heads. These manifolds actually flow so well that the air doesn't start to heat up from friction until the bend just before the heads.

Just out of curiosity, has anybody found the part number for those manifolds in the pic above (the one XX Tuning use)?

I'd be keen to try and find one for a play...

I'm just about finished making one for a 2.5l STi in a GC8. One of the biggest challenges is making it pass the alternator. I'm machining a new bracket for that and flipping it over to the other side but it still only gives about 1/4" clearance for the throttle cables and have to deal with a tensioner for the alternator belt. Depending on the angles the runners entered the plenum I've had a lot of trouble getting equal flow at differing amounts of airflow. Although I think I've mostly got it sorted out now it's not very easy to do. I'll post pics as soon as it's done. Once that's off my plate I should be able to post up some measurements.

-Michael

Here's some shots of the new Tomei setup (sorry I don't have a scanner so i had to use my phone). If some of the terms are wrong its b/c this stuff is a bit new to me so please feel free to correct. The Tomei setup has 4 ITB and use a special linkage to correctly use them. The inlet for the intercooler piping goes under the manifold and comes out just to the right (from front view) of the alternator. The kit is supposed to be around $6k US according to the magazine. We all know Tomei is known for their quality and performance so I'm sure this kit will be amazing. Well on to the pics.

http://i4.photobucket.com/albums/y144/digitalboy40/Cars/TS380076.jpg

http://i4.photobucket.com/albums/y144/digitalboy40/Cars/TS380078.jpg

http://i4.photobucket.com/albums/y144/digitalboy40/Cars/TS380077.jpg

http://i4.photobucket.com/albums/y144/digitalboy40/Cars/TS380079.jpg

where did you see this, from a catalog? Anywhere online we could see?

I'd rather make 600whp than 650whp if it means I get to keep my AC.

awesome thread, just dont know whats the best option still...lol

I'd rather make 600whp than 650whp if it means I get to keep my AC.

It is not all about a single dimension - peak power. For me it is more about throttle response, torque and having the induction system matched to the displacement and intended use.

Better Tomei pics. It is funny how their synchronizer is almost exactly like mine, although this is the first I've seen of their setup.

http://www.iwsti.com/forums/showthread.php?t=88960&highlight=itbs

Better Tomei pics. It is funny how their synchronizer is almost exactly like mine, although this is the first I've seen of their setup.

http://www.iwsti.com/forums/showthread.php?t=88960&highlight=itbs

EIGHT THOUSAND DOLLARS?? They have got to be kidding...

I have seen hand-made carbon composite manifolds, autoclave hardened, with 6 moths of R&D for 1/4 of that price. Someone needs to rethink their marketing plan...

Honestly, I could never in any years justify spending that much money on an intake manifold, EVAR! But the ****s really sexy...

http://www.visual-assault.org/photos/d/1239-1/4thro_ej2025_main_l.jpg

I just put my order in.
in my dreams

not for me ....not at that price !

It is not all about a single dimension - peak power. For me it is more about throttle response, torque and having the induction system matched to the displacement and intended use.

I understand that, but so far the numbers don't seem to justify spending an obscene amount of money AND losing my A/C trying to chase down something that rarely exists - prefection. Especially since this level of modification is right there with "rich guy" types of motor sports.

No shat, if I had 8 large to dump on an intake that means I already dumped 15 large on a motor, which means I've got money to buy a much better "race car" than a damn Subaru.

I understand that, but so far the numbers don't seem to justify spending an obscene amount of money AND losing my A/C trying to chase down something that rarely exists - prefection. Especially since this level of modification is right there with "rich guy" types of motor sports.

No shat, if I had 8 large to dump on an intake that means I already dumped 15 large on a motor, which means I've got money to buy a much better "race car" than a damn Subaru.

my feelings == hurted.

is it realy 8000 or are you guys being sarcastic?

is it realy 8000 or are you guys being sarcastic?

:lol:
According to their site its going to be 764,400JPY which is currently about $6252.02 U.S. dollars. Add the shipping costs, or the distribution + retail markup costs, and you've probably got at least $6500 for a really good deal, and probably $7k from most vendors. $8k from the evil vendors.

And tomei who are a bunch of HWY robbers want to put something out there for all of us to drool over. (i had a dream about this manifold!)

And tomei who are a bunch of HWY robbers want to put something out there for all of us to drool over. (i had a dream about this manifold!)

it'll do well over here in Japan at least, as far as subaru maniacs purchasing it.

i think it was the latest Dsport magazine that I saw the easystreet sti drag car making like 900 whp using what looks to be a stock wrx manifold (not even reversed). If the top drag guys are using the stock mani then its good enough for me...even though some of the aftermarket ones look really bada$$!

Top thread and what a read...
Welldone guys

I agree in the terms of improvement in flow, but its obviously there for pro cars... Ya know, no a/c, ITB's and custom throttle cable. "Its gorgeous" as Steve Erwin would say. I agree with what wittmer25 said though, if it can be done with the stock manifold, spending the $6k it would cost me as a US citizen wouldnt be worth it. Good choice to those who break the bank on the TOMEI. Ill port match my stocker or the 2.5rs manifold and make my 500awhp. cheers

i think it was the latest Dsport magazine that I saw the easystreet sti drag car making like 900 whp using what looks to be a stock wrx manifold (not even reversed). If the top drag guys are using the stock mani then its good enough for me...even though some of the aftermarket ones look really bada$$!

Yes, you can make a lot of HP with a stock manifold, but they would make more with an aftermarket one too. The stock manifold just isn't very good with respect to making max HP up top.

Good thread guys. Thanks for the productive comments on our manifolds Bill. We have yet to push the limits of either car as we suffer the usual development and budget hurdles associated with big projects like this. We'll be able to get some numbers soon for both cars and hopefully hone our design one way or another based on what we find. We're just trying two very different designs to ensure that we're not going down one wrong direction.

The asymmetry on the last photo which was taken at Wicked Big Meet is deceptive. Both ends share the same volume but the photo makes it look otherwise. Since the cylinders on the motor are actually offset it forces one bank to be further back on the motor than the other.

Someone noticed the wastegate over the dogbone. We are using our own twin scroll up pipe. Both sides of the UP have a pipe going to the wastegate, so it's two to the turbo, then two to the WG.

Nate's "Mad Intern" should be rolling onto the dyno early next week.
http://www.dentsport.com/gallery/d/995-2/top_hood_open.jpg

Alex

The packaging constraints of the boxer engine certainly will push creativity with designs. I do not think there is enough room to create a no compromise manifold design and still clear the hood. Hopefully I can post #s from my car in about 1 month, now that it is finally running fairly good now.

It is just difficult to post before/after comparisons with the stock manifold because usually they are not interchangeable on the more heavily modified cars.

http://www.dentsport.com/gallery/d/7759-2/nategt40.jpg

Damn, that's some big frickin' power at some not-very-big RPMs! And on a DD dyno, no less! :eek: :eek:

http://www.dentsport.com/gallery/d/7759-2/nategt40.jpg

how many pounds?

what happens after 7000 rpm?

Really it just keeps going. The car made even more power this morning.

bumpn a good thread. anyone else doing any custom stuff?

nobody seems to be doing anything sadly.. I have money in hand and am looking for something, but it seems that Magnus still is the only option on the market, and looks like they will be.

There is of course Tomei, but who feels like plonking down 6K+ on an intake manifold that looks as if it suffers from the same lack of plenum volume that the stocker suffers from?

Just thought I'd post up a few pics of an IM that I made. I did a few prototypes and a lot of calcs before coming up with this one. The plenum and runner sizes were optimised for mid-high RPMs but there is still enough taper machined into the TGV bodies to provide enough low end response. I will know fairly soon as the car will be ready for tuning soon. I also added bungs for all the factory vacuum lines and brake booster.

http://www.redliners.ca/forum/userpix/2_mani1_1.jpg
http://www.redliners.ca/forum/userpix/2_mani2_1.jpg
http://www.redliners.ca/forum/userpix/2_mani3_1.jpg

-Michael

interesting.... and this fits in teh stock unrotated manifold location without need for modification?

What is your plenum volume?

I would have thought that you would have shorter runners for top-end performance no?

Any idea when this will be proven on the dyno?

looks good :)

Are you going to perform back to back testing with your custom IM and a stocker?

If you look closely you will see that this is a reversed IM. I was approached by someone who wanted me to design and build one. As such it is not really possible to do a comparison.

Last year I did some back to back testing on a custom made IM that a company was making. For the $1000 or so price tag it did not make a significant gain (6-8whp as I recall).

On this unit I spent a considerable number of hours trying to computer simulate the flow dynamics. I even tried to equalize the flow on my bench but I'm limited to about 350cfm and wasn't able to pull enough depression to get accurate enough results.

For the runner length, shorter runners will give more top-end performance but at a significant loss of torque lower down. That will also affect the plenum size. The tradeoff in plenum size is in runner length and the volume can give a less "crisp" throttle response. Another way to do is is to use larger runners which is what I opted to do.

When I get my STi v4 running again I may consider doing a manifold for myself that is not rotated. For that I could do a before & after but I don't know that they'd fit the newer WRX stuff. I think the problem with my design is that although it may be superior from a technical and performance standpoint it would be more expensive to produce. Not $6k expensive though :)

-Michael

Nice looking manifold. Wanna make another one? ;)

doof, if you don't mind me asking...what did you use to design the manifold diameters, runner length, plenum size and flow design?
I'm guessing helmholtz, helmholtz, winged it from experience and fluent, respectively ;)

Last year I did some back to back testing on a custom made IM that a company was making. For the $1000 or so price tag it did not make a significant gain (6-8whp as I recall).

who's manifold is this?

I used dynomation. I've read and studied some of helmholtz's work but wasn't aware of any flow type software of that name. Got any links?

I've also got a few friends who work for Boeing on their turbofans and they've been able to help me quite a lot in setting things up. I suppose this winter I might be able to sit down and make a few, but the trouble would be finding and doing a correct mockup so it would be a bolt-on type affair for a WRX. As you can guess my STi 4 will be slightly different.

As for the one I tested it is from a big name company and I don't like to name names. If I were to produce them then I guess I'd have to set up as such and pay to be a vendor here. I just don't know if I could make them for a competitive enough price. You'd probably be looking at $1200-$1500 a piece.

-Michael

no, I was guessing that you used helmholtz for working out ideal runner diameter and length, used base knowledge and prior experience on plenum size (as many start there) and used fluent for the CFD modeling...guess you didn't ;)

Yeah, I'm still looking to do my intake manifold but am making mine a TGV bolt on affair as I still plan to do roller barrel throttle bodies...my big dilema then will come with placing 8 injectors on it ;)

Also, comptitively priced manifold is quite hard to do unless you have a connection with casting, have a simple to produce design (often not the best manifold) or you don't put cost/high production numbers as a concern :p

Just thought I'd post up a few pics of an IM that I made. I did a few prototypes and a lot of calcs before coming up with this one. The plenum and runner sizes were optimised for mid-high RPMs but there is still enough taper machined into the TGV bodies to provide enough low end response. I will know fairly soon as the car will be ready for tuning soon. I also added bungs for all the factory vacuum lines and brake booster.

http://www.redliners.ca/forum/userpix/2_mani1_1.jpg


-Michael

wow that thing is pretty sweet...

how long did that thing take you to make ??

<--- wishes he had a tig welder :mad:

I machined all the velocity stacks on a mill by hand with a rotary table. I hand ported and used a boring bar on the TGV bodies to get the taper right. I also hand machined the throttle body plate so everything was very labour intensive. I probably have 80-100h into designing and fabricating this one. With all the numbers being done and a very basic jig made I suppose it wouldn't be as bad to do up more. I just don't think there is a huge demand for reversed throttle bodies.

Finally, owning a TIG is only 1/2 the battle as it's only a tool. Took a long time to get proficient at using it.

-Michael

Driver's Image Intake Manifold

http://i242.photobucket.com/albums/ff101/Nilesh_Patel/2007%20MWSOC%20Subaru%20Shootout/DSC03670-1.jpg

Of all the manifolds I hav seen on this thread the one that interests me the most is the xxtuning one
http://www.tunernetwork.com/forum/gallery/data/500/XX_SUBARUS_13.JPG
the question is is it really better than stock? and if so how?
Jon

Of all the manifolds I hav seen on this thread the one that interests me the most is the xxtuning one
http://www.tunernetwork.com/forum/gallery/data/500/XX_SUBARUS_13.JPG
the question is is it really better than stock? and if so how?
Jon

They look like the 2.5i manifolds... Has anyone done any testing on the na manifolds?

yeah, they are just 2.5i manifolds made pretty...oem subaru part

I realise that but are they better than the sti manifold?
they charge over 1k for this manifold so I hope they do more than polish and paint!!

if I were you, I'd just buy a factory one, clean up the castings marks a bit and toss it on...if you care about making it pretty, then do so...but polishing an intake from a rough cast takes a lot of man hours.

Im only interested if It offers a performance boost, all these manifolds being tried but no data, magna claims a boost but other say no?
I like the idea of the NA manifold since it seems to be a very smooth path to the heads but maybe that doesnt matter I just wonder if the subaru didnt have a top mount from the factory what the intake manifold would look like? probably the NA one :).

if I were you, I'd just buy a factory one, clean up the castings marks a bit and toss it on...if you care about making it pretty, then do so...but polishing an intake from a rough cast takes a lot of man hours.

you're tellin me.... :rolleyes:

I've got about 25 hours on mine...and it still isn't perfect :alien:

http://i71.photobucket.com/albums/i152/illnastyimpreza/100_0767.jpg

you're tellin me.... :rolleyes:

I've got about 25 hours on mine...and it still isn't perfect :alien:

http://i71.photobucket.com/albums/i152/illnastyimpreza/100_0767.jpg



Sexy.... Looks like itll be a nice finished product. Im thinking about just cutting out the seperator from the tgvs and leaving it all alone. Honestly, changing your intake manifold at the most will yeild 20hp... at the most. Its not worth the money to buy the aftermarket manifolds out there. All you have left is your time and some die grind bits... Might as well port your tgvs all the way and leave it be after that. 2.5i manifolds p+p is as far as ill spend... That and a nice wrinkle red or black heat coating...

Of all the manifolds I hav seen on this thread the one that interests me the most is the xxtuning one
http://www.tunernetwork.com/forum/gallery/data/500/XX_SUBARUS_13.JPG
the question is is it really better than stock? and if so how?
Jon

If you look closely there is a huge difference in the way the plenum is shared, compared to the turbo manifolds...
Look at how the runners are crossed...
They are crossed so that only one cylinder can pull from that area of the plenum at a time...

Some people will argue that it doesn't make a difference on a turbo engine, but it does...

The runners are also longer than the turbo manifolds as well...
There are pros and cons to that as well...
Using the longer runners, lowers the torque curve...

to clarify so that some don't get confused...longer runners shift your torque cruve lower in relation to rpm....comes on sooner ;)

what about the inlet manifold is on the aps website?? is under international cars, subaru turbos or intercooler applications...

If you look closely there is a huge difference in the way the plenum is shared, compared to the turbo manifolds...
Look at how the runners are crossed...
They are crossed so that only one cylinder can pull from that area of the plenum at a time...

Some people will argue that it doesn't make a difference on a turbo engine, but it does...

The runners are also longer than the turbo manifolds as well...
There are pros and cons to that as well...
Using the longer runners, lowers the torque curve...

The 2.5 N/A runners are also a lot larger in cross section than the WRX/STI runners.

These intakes may not be 'optimal', but after the modifications (About 10 hours of labor...I did the first four or five of these intakes for XX so I know how much labor is involved), they do make good power, particularly on a well-modded engine. I would not bother with one of these intakes unless you are going with GT35 or bigger turbo, and unless you have cams and headwork, IMO. The most impressive thing about them is not the peak power, but rather the area under the curve.

Bob

Do you have comparison dyno charts so we can see the difference?

Do you have comparison dyno charts so we can see the difference?

I do not. While I observed some of the early dyno runs, my only relevance to the project was the manifold prep itself. However I'd keep watch in the 'proven power bragging' section, as there are numerous engines at XX Tuning that are going to be tuned in upcoming months.

Unfortunately they are all full-on projects (rollcages, suspension, brakes, body mods, etc.), so while the engines are largely complete it may be a while before they are dyno'd. I know the shop's owner has a GT35 for his 2.5 litre WRX, one customer has an APS TSR70 with a Cosworth 2.5, and another customer has an Ultimate Racing GT4094 on a 2.8 block with headwork and cams (Crawford?).

Bob

I like this thread. What are some of you guys using for thermal coatings? I need to get my intake done soon. I'd prefer something similar to the stock STI coating or other thermal dispersion coating.

http://www.finishlinecoatings.com/engine.htm

^^I'm after function over form. A flat sheen on the intake doesn't bug me and I think it would look kinda cool.

What are some of you guys using for thermal coatings? I need to get my intake done soon.

I would shy away from using any type of thermal barrier on an intake manifold. Any coating that is effective at keeping heat out is usually effective at keeping it in as well. So once your intake heat-soaks from thermal transfer (via the heads), it will not shed the heat as rapidly.

I do however suggest a pair of phenolic (or similar mat'l)) spacers for under the intake manifold. It won't completely stop heat transfer, as some heat still travels via the fasteners and through convection, but while running on the dyno the intake will be virtually cold to the touch. Only after a few minutes of idling does the runner's heat climb again, but once under load the air's velocity passing through the runners drops the runner temps drastically. It's an interesting phenomenon. Last time I checked XXTuning was having the phenolic spacers CNC'd.

I would shy away from using any type of thermal barrier on an intake manifold. Any coating that is effective at keeping heat out is usually effective at keeping it in as well. So once your intake heat-soaks from thermal transfer (via the heads), it will not shed the hea