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Old 03-26-2009, 11:39 PM   #1
HamFist
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Default Wound eye stiw doo eet wong!

I had another crazy idea that popped up and I sprung for the parts. My prototype header worked well, but I was in search of more low end torque. I picked up a bone stock GC header, built a trackpipe, and used an STI 2.5in exhaust. The sound isn't "amazing" but is a little sophisticated, actually. It sounds almost exactly like a Nissan Murano or a stock Infiniti exhaust. It's not rumbly at all but still sounds like a Subaru.

WRXs see the best gains from stock headers that are ported. I want to see if there is something hiding right under our noses that we've all been missing...again. Since my stock motor isn't pushing obscene power it shouldn't need more than the stock header diameter. The problem is working out the kinks and inefficiencies.

My other header that I made picked up more power when I did this porting trick next to the valves. I made sure to do before and after dyno comparos of it a few years ago. The curve was flatter and elevated with better midrange after I ported it. I know people have ported the factory piece but it didn't pop up in a search. The usual suspects hadn't written anything on it .
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Old 03-27-2009, 01:15 AM   #2
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I'm using an STi catback with a catless track pipe.
Sounds mean.
But there's a lot of valvetrain noise.

Anyway, so what're you saying here?
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Old 03-27-2009, 02:00 AM   #3
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Anyway, so what're you saying here?
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Old 03-27-2009, 02:44 AM   #4
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Valvetrain noise is just age. I'm glad you popped up early, Xan. An afternoon with a dremel would be a helpful comparison if we time it right and work together. You've got exactly what I have. My trackpipe is 2.5in dia. I like how nasty and subtle this setup is. Does it sound tuned more like a "tight guitar string" rather than an "open organ pipe?" It's the way this barks and resonates that appeals to me. It gets the point across in a classier fashion than a Honda-like "BLLLAAAAAAAAAGGGGGGGGHHHHHHHHHHHHH". Let the Hondas sound like outboards. Subarus don't need to sound like Cessnas . The diameters and flow of this combination are why I chose it. The sound is sweet with just the right intonation and volume.

The biggest problem with the stock header is right next to the exhaust valves. With porting, mods closest to the valves have the biggest gains. Headers aren't far behind and there is a very nasty flaw in all stock wishbone NA headers. Inside the flange is where the flow problem exists. Grind that second lip down until it's a smooth transition into the primaries. You'll see it when you take it off. We're not enlarging the port entry. It's that secondary lip inside the header flange. The acoustic qualities of this combination are going to be what helps us determine how effective this porting mod is. Xan, if you're willing to play this will be a good exercise. You know that particular "raspy bark"? It should become deeper and sharper. We're still tuning pipes, here. In this fun and interesting case, they happen to sound like a guitar string! When you get on the throttle that bark gets muffled up top. It should bark all the way through the rev-range.

For the last 10 years that we've all been messing with Scooby exhausts...has a "good answer" been laying right under our noses? Stock header pieces work best on WRXs. Are we all doing it wrong looking at shiny bolt-ons for our NA cars? I know this will work, but I don't know how well. I'll get some files up of that particular weird barking noise compared to Borlas.

Last edited by HamFist; 03-27-2009 at 02:51 AM.
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Old 03-27-2009, 01:50 PM   #5
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Ah. Mine is 2.25in - it's one of the new MS3 ones. It sounds a little hollow. But especially when I drop the RPMs to brake or something, it sounds like a snarling wolf.

I have no problem chopping up my stock headers.

Just gimme some instructions. I'm just going to grind down the lip inside the header, right past the flange?
And, well, I'm not sure why I'm doing this. But any excuse to get under my car and experiment is fine with me
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Old 03-27-2009, 09:09 PM   #6
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If I had pictures, I'd post 'em. I'm going out to do this tonight and get some up pics up when I'm finished. This isn't hard to perform, but you guys do need pics. As far as the airflow is concerned with that ridge---it's like barfing into a toilet with the seat down instead of up. It's literally splashback that killing the airflow..err...puke?

It'll be black in there when you pull the headers. Be sure to take the header completely off and get it in good light. You'll see that secondary ridge I'm talking about just inside each header's port. You'll see what I'm telling you to modify, even if you don't understand why you're doing it. It requires some finesse at a downward angle to blend that ridge into the side of the flange with a grinder. You're smoothing and blending, NOT GRINDING AND CHOPPING!

I want to know if this rumor is actually true . Right now, the virgin stock piece feels like a stock RS instead of my RS. Remember those harmonics I told you about? That should become refined throughout the rpm range. It should go into a silent "mmmmttttt" noise...it should still growl. It also shouldn't feel as ****ty under your foot. This mod woke up the top end of my modified stock header. What is it going to do simply to my stock header? I learned a while ago to start near the valve, but never tried this on just a stock car to see what happened. WRXs love it. What about an RS?
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Old 03-28-2009, 06:02 AM   #7
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I'm one tube of RTV short of a complete writeup. Got the pics, but we'll see how well it performs when not leaking air .

No sleep posting tonight...er...this morning.
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Old 03-28-2009, 09:02 AM   #8
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Dang.. I wanna hear an audio clip
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Old 03-28-2009, 02:26 PM   #9
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Ok. No more leak! aaaaaaaaand....guess what works really really well? It's no record breaker, but this fixes what I 100% believe is a flaw in the factory wishbone header design. It doesn't feel choked at all. I've never had a stock header with this kind of response. It feels like a much better header getting rid of that ridge. I'll post pics when my errands are done. It drives nicely and has much better low end driveability than my other header. However, the top end doesn't quite feel like it is really there. Audibly, that bark extends all the way to redline now. Xan, you should hear and feel a difference in your car.

Certainly no broken records, but the results are worth the work. There are flaws in the stock header worth addressing and I have one more to try out in a little while. I think my header design had too big of a piping diameter to be honest. However, I was also fixing the flaws that I saw in the header. I'll do that with this header but keep the piping diameters smaller and longer. My header felt great on the top end, but this feels like a much, MUCH better right off idle. It drives like stock, but much better.
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Old 03-29-2009, 01:32 AM   #10
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Alright. So I'm smoothing out the ridge just below the engine-side port of my headers, correct?
PM me everything you've got, I'll take care of this **** tomorrow

And, I mean...this is basically going to give me the same results as aftermarket headers, in terms of power, right?
Or at least in terms of sound :3
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Old 03-29-2009, 02:05 AM   #11
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Doing a single port is up to you. But yes...every USDM N/A Subaru has this "flaw" or little "inefficiency" that makes a BIG difference. STIs were scrutinized a whole lot more. They don't have any little flaws like this resulting from lack of attention to detail. These cheap old wishbone headers are probably all over the world. This "ridge" at the flange I'm talking about causes an increase in backpressure against the exhaust valves. This phenomenon gets worse as revs climb and more hot gas is pressurizing the exhaust.

It's going to be very different for a single port. I hope it works for ya, and best wishes! I bet that header is just as crappy inside the header flange. Don't get greedy with the grinder. You are doing a "bowl blend in the header flange". Clean it up with some degreaser or brake clean and let it soak up the carbon a bit. Wipe off the area and let it evaporate before you get busy. Carbon is absolutely everywhere on that header ridge that sticks into the port like a sore thumb. It's not rust at all, but black carbon around that ridge.

Header Dojo rules:

1. don't hog the header out
2. don't grind the flange
3. create a smooth transition from the flange into the header piping, eliminating that ridge.

Turn this shape at the header flange
_______
H_____H

to this
______
\_____/


That ridge is killing power in a stock car...badly.

Last edited by HamFist; 03-29-2009 at 02:16 AM.
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Old 03-29-2009, 02:09 AM   #12
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"bowl blend in the header flange"

...wat?
I'm just smoothing the walls of the header out to get a uniform surface, no?
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Old 03-29-2009, 03:10 PM   #13
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I'm sorry these took so long. Here's the restriction I was talking about.



Here's what it should look like as you progress in each port. Don't leave the half assed version on the left. You aren't done until the top of that primary pipe blends into the side of the flange about a 1/4 inch below the flange. You're introducing a smooth transition from the flange into the primary pipes.



...and a grainy cameraphone shot of the final product.


Smooth that ridge into the header flange instead of trying to cut it out. You'll trim down the upper part of that lip to create the transition into the header. Do the final blend with a rounded stone to give it a nice curve. You've now replaced that nasty ridge with a nice smooth transition into the header.

I used a Sears dremel at 10k rpm for about 2 hours. Use the grinding stones that come with the kit. A cutoff wheel or die grinder I don't think will do it with any finesse. Take down that inner most ridge with a 1/8in disc stone in the dremel end. The second step uses a rounded stone in the dremel to create the smooth transition. That sets up the final step of blending into the header flange. That first cut takes the longest in each port to get rid of that ridge in the first pic.

If you were the exhaust gasses leaving the head, you'd "hit your head on the door frame" without ducking. We're eliminating this "door frame" inside the header flange.

One more note of interest for the rest of you still trying to figure this out. There is a ton of carbon buildup on that ridge we're removing. Every factory n/a Subaru has that problem. Once it's gone, there's no more carbon buildup next to the valves. The carbon you have to knock down to get to the ridge is there because of the ridge in the first place.

Last edited by HamFist; 03-29-2009 at 03:44 PM.
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Old 03-29-2009, 03:51 PM   #14
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Time to find my dremel again x_x
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Old 03-29-2009, 04:14 PM   #15
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Quote:
Originally Posted by HamFist View Post

WRXs see the best gains from stock headers that are ported.

totally not true......


do you ever see any real "big" builds from people or shops with just a PnP stock header?

just saying, especially from tuning wise I can tell you my HKS header (wrapped) gave me more power before and after tuning then my tuners PnP and heatcoated and wrapped stock manifold. He even told me he loved the gains out of the HKS header and wished he didnt do his PnP.

i've seen people say PnP is the best but really its VERY minimal gains at all. tho this is for WRX's....i'd still think a aftermarket header would still produce more WHP then a PnP header any day for a N/A.
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Old 03-29-2009, 04:30 PM   #16
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STOP the benchracing. DON'T start.

Watch:

http://www.youtube.com/watch?v=HlfM3...eature=related

http://www.youtube.com/watch?v=tIqWZ...eature=related

Put up or shut up about using stock manifolds. Especially about using them in real life instead of on the internet and on the dyno. Both of those vehicles use them. That's why I'm looking harder at these stock pieces for improvements on my n/a builds. BTW, Jamie Rigoli is unfairly banned here simply for disagreeing a lot with you benchracing retards measuring your dicks on a dyno. I think DBRONX was too, or he just doesn't come around anymore. There's not much of the international contingent here...ever notice that? Personalities aside, you really can't argue with their results except for demanding pics or it didn't happen

Here's what I did with a stock manifold over a stock RS...while I was still using a bone stock motor.



Wound eye stiw doo eet wong...We've ALL been missing something, even me. I've never done this on a single port, so I don't know what Xan's results will be. I do however firmly believe we're missing something with the stock headers on these cars. It starts right there at the header flange .

Last edited by HamFist; 03-29-2009 at 05:11 PM.
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Old 03-29-2009, 05:40 PM   #17
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Quote:
Originally Posted by HamFist View Post
STOP the benchracing. DON'T start.

Watch:

http://www.youtube.com/watch?v=HlfM3...eature=related

http://www.youtube.com/watch?v=tIqWZ...eature=related

Put up or shut up about using stock manifolds. Especially about using them in real life instead of on the internet and on the dyno. Both of those vehicles use them. That's why I'm looking harder at these stock pieces for improvements on my n/a builds. BTW, Jamie Rigoli is unfairly banned here simply for disagreeing a lot with you benchracing retards measuring your dicks on a dyno. I think DBRONX was too, or he just doesn't come around anymore. There's not much of the international contingent here...ever notice that? Personalities aside, you really can't argue with their results except for demanding pics or it didn't happen

Here's what I did with a stock manifold over a stock RS...while I was still using a bone stock motor.



Wound eye stiw doo eet wong...We've ALL been missing something, even me. I've never done this on a single port, so I don't know what Xan's results will be. I do however firmly believe we're missing something with the stock headers on these cars. It starts right there at the header flange .

all of my real life results where from before/after open source tunes. no dyno graph but with all the parameters in the Enginuity program you can see and feel the difference.
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Old 03-29-2009, 06:01 PM   #18
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This is surely interesting as this mod would be so darn easy with a simple dremel and an AlOx Wheel.

I like that dyno chart. The torque is flatter with less irregular bumps, and the HP has a nice climb until it can't breath anymore which isn't anyone's fault. (Except for the Subaru Engineers who decided to make the valves poorly breathing at high end)

I suppose the non-modded header hits it's max flow earlier too since it seems it levels off a lot earlier and lower than the modded headers.

--edit--

Now if we can get rid of the nasty turn before the cat section, we're good to go. There must be a simple way we can cut off the end section and weld together a straight collecter. The cat section would be then lengthened and/or modified to meet the header at the new location. Anyone think or this or try it out on a drawing board? I bet that a exhaust shop would do it cheap if we got it to work.
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Old 03-29-2009, 06:13 PM   #19
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Haaaa sooo gwasshoppa! Good jahb, formula91. That was where I was going to go next. A header shop could fix that last part for about $100-150. It's a price anyone can swallow with their Subie based budget. You can support your local economy or your own welding and grinding crack habit! It's a tight bend to pull off with a new collector.

Pull off your cat and look directly into the header with a flashlight. There is a baffle in there that the passenger side air runs perpendicular into. That flange in there is the other issue. However, one thing at a time. Reset the computer after the modification so it relearns. You basically are installing new headers...sorta...

I'm resetting my computer to see if it makes a better difference. These things get fussy after an air leak and need a clear head . If you drive with a gasket leak, replace the gasket and reset the ECU. Leaks happen and they also piss off the computer's o2 readings.

Sedona--I don't doubt your gains..but no one has really even heard of this. I had to stomp out the bench racing. (Instructa put you on yo back in class, while otha students watch demonstration. Backa to yoa classmates.)

Last edited by HamFist; 03-29-2009 at 06:23 PM.
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Old 03-29-2009, 06:48 PM   #20
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Sedona--I don't doubt your gains..but no one has really even heard of this
no one has really heard of what???


its all over the 2.0, 2.5, and proven power threads about how people think PnP is better then a header. most recently someone put it to the test and did a good write up on it. to lazy to find but idk what you mean no one has heard of this....
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Old 03-29-2009, 06:58 PM   #21
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susbcribed since i just got my stock headers PnP
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Old 03-29-2009, 09:56 PM   #22
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Quote:
Originally Posted by SedonaScooby View Post
no one has really heard of what???


its all over the 2.0, 2.5, and proven power threads about how people think PnP is better then a header. most recently someone put it to the test and did a good write up on it. to lazy to find but idk what you mean no one has heard of this....
It's not widely known here in n/a land...in addition to pretty much not being believed at all. The header is assembled in sections top to bottom and left to right out of stamped halves. Then, they're welded up from the outside. It's a totally different assembly procedure for these headers and that's what we're all working around doing it like this. I built my stuff in sections on the stock header, and you can to...for stupid cheap, with possibly better results than other applications. You just need the clues to try it .

I've been here 10 years inventing new stuff quietly in my garage, basement, and other places. It's eccentric to believe it possible and crazy to think it works...kinda like everything else I've come up with and written about here. None of you understood fuel static and lead application. This, you can whittle on like cavemen.



The last section is that baffled clamshell at the base of the header. It's cheaply assembled. Someone find one of these sections below and replace that little juncture at the cat flange. The header itself actually went together exactly like the heat shield, but welded. Look at the seams on a naked header and you'll see what I mean about the assembly. This is not German build quality with its stamped, pressed, and stitch welded assembly. Peer into the back of the header flange and you'll plainly see that welded in baffle in the collector. Replace that with a REAL header collector.

Last edited by HamFist; 03-29-2009 at 11:50 PM.
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Old 03-29-2009, 11:13 PM   #23
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Get a real grinder with some POWER! Then you can do this in about 30 minutes.....
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Old 03-29-2009, 11:32 PM   #24
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Quote:
Originally Posted by HamFist View Post
STOP the benchracing. DON'T start.

Watch:

http://www.youtube.com/watch?v=HlfM3...eature=related

http://www.youtube.com/watch?v=tIqWZ...eature=related

Put up or shut up about using stock manifolds. Especially about using them in real life instead of on the internet and on the dyno. Both of those vehicles use them. That's why I'm looking harder at these stock pieces for improvements on my n/a builds. BTW, Jamie Rigoli is unfairly banned here simply for disagreeing a lot with you benchracing retards measuring your dicks on a dyno. I think DBRONX was too, or he just doesn't come around anymore. There's not much of the international contingent here...ever notice that? Personalities aside, you really can't argue with their results except for demanding pics or it didn't happen

Here's what I did with a stock manifold over a stock RS...while I was still using a bone stock motor.



Wound eye stiw doo eet wong...We've ALL been missing something, even me. I've never done this on a single port, so I don't know what Xan's results will be. I do however firmly believe we're missing something with the stock headers on these cars. It starts right there at the header flange .
nice graph, but out of curiosity do you plan on comparing your pnp'd header to a borla or equal length header?
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Old 03-29-2009, 11:51 PM   #25
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Why? I'd rather **** with a WRX owner

Actually, I did compare my other header already. It's the other one I built a few years ago and have been running all along. I want to see if overall that this can be a better design.

Fuji built this one, or contracted it, or whatever. I'm just improving it for dirt cheap and beating WRXs. Borla spent $5 million trying to beat the factory header instead of using it or learning from it. The enthusiasts demanded a better design instead of working on what was there. They also tried to "beat" it. Work with it instead. You don't fight the rest of the car, do you?

I have a pretty direct comparison around here somewhere. I want one where they're both on the same fuel, though. Gas vs. gas is more fair to compare. Basically, the Borla made more peak torque at 3500rpm. My modded stock header made more average torque and 12whp more from 4500rpm to 5500rpm.

That baffle on the end of the header is what I cut out and replaced on the stock unit to beat Borla, and WRXs, and V8 muscle in real world instead of on paper. The flat, rapid torque is a deadly combo. Why wait for a turbo to spool when you can smack the rev limiter with torque? I hit the rev limiter and shift before a WRX spools. A good driver knows how to double clutch and get his boost up in time, otherwise it's over because mine revs so fast.

Just for argument's sake, what is it about this stock header than supports 9.0 timeslips? I don't think it has a baffle before the downpipe, does it?


Last edited by HamFist; 03-30-2009 at 12:32 AM.
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