Welcome to the North American Subaru Impreza Owners Club Thursday September 18, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 10-09-2006, 06:44 AM   #201
X4 SRT
Scooby Newbie
 
Member#: 40636
Join Date: Jul 2003
Location: Las Vegas
Vehicle:
2001 2.5 RS Coupe
Silver

Default

Quote:
Good points, something I know I didn't make clear in my original posts. In fact, first post on the very next page (#141) you yourself pointed out to me that you can't add the numbers and get your power, to which I replied that it actually was the whole point of my post, and a big reason why the SubieSport car didn't get close to the numbers of just the bolt-ons in Rally_wgn's list, despite having much more than that list. Matt Monson's statement that magazine numbers are inflated for the guys donating their gear just makes it worse. That Subiesport number may have been 5% or 10% high, but nobody will ever prove it so I'll stick with their number. That is always the danger of claiming "an intake makes X" or "a header makes Y". In relation to what? What are the other factors that might influence X or Y? A header might influence an intake's gain and vice versa. A cam affects what both intake and exhaust sides are doing. A comp'd part for a magazine cover article can work wonders for that car.
Where in Matt's post did he say not to trust the performance gains stated in a magazine? I just don't see it. What I do see though is Matt telling people to not beleive what the Subiesport magazine says the cost of headwork was for the zth car. They claimed it cost them 675 for mild porting of the heads. Matt said that number was low probably because magazines get good deals on parts, and that one should really expect to pay somewhere around 1500 for some head work. That's what Matt is trying to say. I think you need to carefully re-read his post before you make such claims.

Quote:
You clearly did not learn anything from this thread. One of the points mentioned over and over...

Never believe the claims of someone who has something to gain by them.

Area1320 made the spacer, therefore their tests are null and void untill verified by an independent party in the real world. Particularly considering their gains are well within the margin of error on the dyno. They could have very easily taken two dyno passes done without the spacer and got similar "gains"
Exactly what did this person not learn from reading this thread? Please tell me, instead of bashing someone for putting up information that is in fact helpfull to a lot of people, even if you don't think it is.

Just because the maker of the product did the dyno test does not make them worthless. Just because someone has not tested it the way you want it tested does not make it worthless.

Here's an idea. Since you like to complain so much about dyno numbers, and who's putting them out there, why don't you buy all these parts, and have every single possible combination tested so we can see the results. At least this way everyone that reads this thread form here on will know that the parts have been dyno tested in the proper manner, and what we should really expect for performance gains.

Please stop crying like a baby. If you actually have anything useful to add go ahead and do it. Otherwise stop crying about this and that and what you beleive is right and wrong. Because with out any proof of what you say, you're just rambling.

Now, onto something a lot more interesting. The Subiesport ZtH build.

Has anyone read the latest Subiesport article? I just got a copy yesterday and read that article right away. Very interesting read to say the least.

First thing I want to mention about the build is the total cost. 11,558.28 without labor. That's a lot of money. A hell of a lot of money. You can easily take out almost 5k off the total price of that build. Subtract 2300 for the cobb shortblock, and then subtract 2600 for the prodrive wheels. Does anyone else besides me think it's total BS to spend more on wheels than on your motor. Don't get me wrong they are nice wheels, but 2600. I don't think so.

As for the Cobb block. It's a nice investment especially if you're planning on running the motor to 8k. You know that the motor is fully balanced and blueprinted and can handle anything you throw at it. But, is it necessary for someone doing a lighter build. Should one invest in a block like this if they are doing cams and going no further? IMO no. You don't really need it. If your goal (like mine) is to get cams and new valve springs in the car and call it a day then you don't need a block like this. You aren't going to rev it out past it's limits, and your stock block is more than stout enough for this kind of abuse. Again IMO.

So from there we have brought the cost of this build down from 11,558.28 to 6658.28. Now that's not cheap, but it's a lot less expensive than 11.5k. Then, if your goal is just cams then you don't need the head work done, so according to the subiesport article you can knock another 675 off the price tag to an even lower 5983.28. We are almost to a more consertive price range, so lets take out a few more things that you probably won't need...pistion coatings 175...cylinder head coating 354...Carbon fiber hood dampers 169...now we are looking at a price of 5285.28. And you get a lot of stuff for that money.

What kind of numbers can one expect from this kind of build I have kinda of sort of, but not really outline above. From what I've read on the boards for the past several years is one can expect anywhere between 200-210chp. Honestly those are some very decent gains. 35-45chp is nothing to laugh at in a 4 cylinder 2.5litre N/A car. If you're one of the lucky ones and own an older 98-01RS, then this is enough power for you to keep up with stock WRX's, and maybe even outrun them. Lighter weight and shorter gearing are to our advantage. However if you own a newer RS (read 02-06) then you will need more power to keep up with the WRX at which point you would have to look into head work and a built motor. Sorry.

Now let me get into the amount of power the ZtH car is making. Am I surprised that they made "only" 160whp. No I'm not. Honestly they do have a somewhat conservative build. From what I've read they really were trying to make a well balanced daily driver. Something that retained low end torque, and was still easy to drive around town. If they wanted to make more power they would have to do a bit more work. I'm not sure exactlly what they would need to do, but I do have some ideas.

First off they need a more agressive cam as stated in their article. In order to make more power they have to cram more air in, and the only way to do that is to get a more agressive cam. They need a cam that moves the power band up and to the right. Will driveability suffer. A little I'm sure, but it won't be that bad. It's not like you're going to loose all of the low end torque by using a more agressive cam, and even if you do lose some, the gains in the top end will be well worth it.

After they run a more agressive cam they will need more than mild perting on the heads. They will need full on head work. From reading the article they have very light headwrok done. They will need somthing along the lines of what TWE describes as stage two headwork, or for more power stage three headwork.

I'm going to say that with a more agressive cam and very serious headwrok, they would see some nice gains. With tunning I would guess they could anywhere between 10-20whp (those are just guesses Falcon don't get your panties in a bunch )

So that leads me to the tuning of the car. Cobbs AP for the RS. Nice to see one is supposed to be coming out for the newer RS later this year. It will be a nice option for you guys.

Looking at the ZtH dyno and AFR graphs there are some interesting things to take note of. Has anyone else looked at this. In the graph they compare Stock, Tuned on the stock block and heads, Built motor before tuning, and Built motor after tuning with Cobb AP.

The thing that interest me is the amount of power the Tuned stock block and heads are making in relation to the AFR's. The AFR's on this setup begin running very lean, and then drop like a rock and run at about 10.5:1 at 6k rpms. At the point where the mix becomes rich power is lost like crazy. Why is the car running so rich? This was tuned with the PP6 correct? I know that it was able to only tune in open loop mode, but why would they run such low AFR's. I would think that by leaning out the mix quite a bit more power would have been made on this setup.

Then lets get to the fully built motor that is tuned with the AP. The AFR's are very nice ( right around 13.5:1), and don't sink like a rock like the graph does with the PP6. However IMO the car can probably be run just a little more rich and see a slight increase in power. Am I wrong in thinking this? Could the AFR's be dropped to around 12.5:1 and see a decent gain in perfromance?

Overall, comparing all the graphs together there are very nice gains. When looking at the graphs you can see that peak numbers may not be incredible, but the overall difference in the midrange, and power at redline is amazing.

Good job SUbiesport. Lets see what else you have in store for this car. Hopefully more than just Nitrous.
* Registered users of the site do not see these ads.
X4 SRT is offline   Reply With Quote
Old 10-09-2006, 09:49 AM   #202
Back Road Runner
Scooby Guru
 
Member#: 60082
Join Date: Apr 2004
Chapter/Region: MWSOC
Location: Minnesota
Vehicle:
2004 Forester STI
Silver

Default

During my dyno day a few weekends back, I was talking to the shop owner/dyno operator about my graph. One thing he noted was the AFR dropping off at a certain point. He continued on to say that AFR has almost no effect on HP. He discussed his old school class example where they specifically ran an engine from an AFR of about 4:1 up to 16:1 just to show what it does. I don't recall the engine, being in a class room environment, it was probably some generic, barebones inline 4 or maybe a small V8.

Guess how much HP varied?

2HP Yep, 2HP from lean to rich.

Now he pointed out that the AFR wasn't causing the power loss, a very common misconception as he stated, but it was an indicator showing that the engine was doing something it probably shouldn't be doing, i.e. retarding timing like crazy.

Then you ask why is it retarding time. I don't know for my car. I had 30k on cheap Chamions, and a recent swap to some new NKGs show an improvement in smoothless. Maybe the O2 sensor is reading something or the Knock sensor gets a little goofy. I wouldn't mind trying a grounding kit and redynoing my car again. Too bad you can't measure timing without going into the ECU and looking at it.

Anywho, I thought I'd share. I guess it's more of a matter of X amount of fuel vapor will burn with Y amount of oxygen in the air. If you have excess of one or the other, it just doesn't get used. Although, I'm suprised lean wouldn't lose more power. Then again, it's a heating process and maybe there's an efficiency/time thing associated with it. Of course you can't just run lean or you'll burn up the engine. We use a lot of fuel to cool as well.
Back Road Runner is offline   Reply With Quote
Old 10-09-2006, 11:14 AM   #203
FalconRS
Scooby Specialist
 
Member#: 92913
Join Date: Aug 2005
Chapter/Region: W. Canada
Location: Winnipeg, MB
Vehicle:
2005 2.5RS Wagon
Crystal Grey Metallic

Default

Quote:
Originally Posted by X4 SRT View Post
Exactly what did this person not learn from reading this thread? Please tell me, instead of bashing someone for putting up information that is in fact helpfull to a lot of people, even if you don't think it is.

Just because the maker of the product did the dyno test does not make them worthless. Just because someone has not tested it the way you want it tested does not make it worthless.
How is the information helpful? You can't even consider the gains a valid gain as the number they gained was smaller than the margin of error on the dyno. If those in fact are the gains, then they're too small to be measured. Take what took pages of debate to explain that you can't just add up the gains from each part and get your number, where does this even factor in?? It absolutely needs mentioning. The real gains from the spacer would be if they take up the "torquebox delete" slack and prevent the low end torque loss (unsubstantiated, but intriguing claims) or gave a significant gain in fuel mileage (this people have actually seen, and why I'm interested in the spacer myself).

Quote:
Here's an idea. Since you like to complain so much about dyno numbers, and who's putting them out there, why don't you buy all these parts, and have every single possible combination tested so we can see the results. At least this way everyone that reads this thread form here on will know that the parts have been dyno tested in the proper manner, and what we should really expect for performance gains.
1. No dyno within a 6-hour drive from me, or the parts I've accumulted thus far absolutely would be tested. Properly.

2. Since you think I'm so far off base with what I'm saying, why don't you test them and prove me wrong?

Quote:
Please stop crying like a baby. If you actually have anything useful to add go ahead and do it. Otherwise stop crying about this and that and what you beleive is right and wrong. Because with out any proof of what you say, you're just rambling.
What I was doing wasn't "bashing". Calling someone names? Last resort of the weak minded. Classy.
FalconRS is offline   Reply With Quote
Old 10-09-2006, 11:29 AM   #204
Matt Monson
Scooby Guru
 
Member#: 832
Join Date: Jan 2000
Chapter/Region: RMIC
Location: Teh Ghetto Garage, CO
Vehicle:
99 2.5RS, '85 911
'73 914 and 2012 BRZ

Default

Quote:
Originally Posted by X4 SRT View Post
Where in Matt's post did he say not to trust the performance gains stated in a magazine? I just don't see it. What I do see though is Matt telling people to not beleive what the Subiesport magazine says the cost of headwork was for the zth car. They claimed it cost them 675 for mild porting of the heads. Matt said that number was low probably because magazines get good deals on parts, and that one should really expect to pay somewhere around 1500 for some head work. That's what Matt is trying to say. I think you need to carefully re-read his post before you make such claims.
Thanks X4 SRT. I would love to see where I said not to trust magazine's numbers. If people are going to bother to drag my name into their arguments (and through the mud) please have the courtesy quote me and not take my remarks out of context...

As for the rest of it all, I don't personally feel that all this debate "dillutes" the thread. The most important information remains in the opening posts and on the first page or 2. If people keep reading and start to read this stuff and it doesn't suit them, they can just close the thread. While there is some bickering on the latter pages of the thread, if one has the patience to wade through the egos and the arguing, there's still very good technical content coming out that was not in the initial posting...

As for this whole current debate about the value of different mods? The only thing I wish to point out is that there will be quite a range between the best and the worst parts. I will make a known dyno prooven example of Borla headers vs Cobb headers. From what I remember, and you can look up the numbers is you think I am wrong, a Borla header will give you about 6whp while Cobb's give you 12whp. That's a huge range. You will find the same sort of ranges with other parts with some intakes giving you 5whp and others giving you 12+whp. And as usual, you can't "add" them all together.

I think now is a good time to throw out BSFC. There's a handful of good threads out there about it, and finding one of them and linking it in the opening post would be worthwhile. What Shiv showed years ago was that BSFC limits the Ej25 to about 185chp. In abesence of headwork and/or cams that significantly change the nature of the engine, that's the limit. You guys can argue all day long about exhaust and intake etc. etc. but you aren't going to get much more than 185chp...
Matt Monson is offline   Reply With Quote
Old 10-09-2006, 12:00 PM   #205
FalconRS
Scooby Specialist
 
Member#: 92913
Join Date: Aug 2005
Chapter/Region: W. Canada
Location: Winnipeg, MB
Vehicle:
2005 2.5RS Wagon
Crystal Grey Metallic

Default

Quote:
Originally Posted by Matt Monson View Post
I think now is a good time to throw out BSFC. There's a handful of good threads out there about it, and finding one of them and linking it in the opening post would be worthwhile. What Shiv showed years ago was that BSFC limits the Ej25 to about 185chp. In abesence of headwork and/or cams that significantly change the nature of the engine, that's the limit. You guys can argue all day long about exhaust and intake etc. etc. but you aren't going to get much more than 185chp...
I believe this is what SubieSport was getting at when it talked about the limitations of the engine, and that PART of the solution there was the cam. Certainly makes sense that one or two mods have often shown great gains on their own but when guys hit the track or dyno with more parts the gains just aren't there. Drop in a cam though and there you go making numbers again.

Quote:
Thanks X4 SRT. I would love to see where I said not to trust magazine's numbers. If people are going to bother to drag my name into their arguments (and through the mud) please have the courtesy quote me and not take my remarks out of context...
My apologies for twisting around what you said, had it happen to me before and it's a PITA. Just got a little overzealous in my crusade.

That said, I do feel that when I'm flipping through a magazine and find them doing an "independent test" on a particular part, then flip a couple pages and find a full color 2-page ad spread on that very part, I can't help but take that "independent test" with a grain of salt. That magazine is being paid to promote the company's part.
FalconRS is offline   Reply With Quote
Old 10-11-2006, 11:18 AM   #206
SubaDuba420
Scooby Specialist
 
Member#: 102793
Join Date: Dec 2005
Chapter/Region: NESIC
Vehicle:
2008 STi
DGM

Default

Quote:
Originally Posted by Matt Monson View Post
I think now is a good time to throw out BSFC. There's a handful of good threads out there about it, and finding one of them and linking it in the opening post would be worthwhile. What Shiv showed years ago was that BSFC limits the Ej25 to about 185chp. In abesence of headwork and/or cams that significantly change the nature of the engine, that's the limit. You guys can argue all day long about exhaust and intake etc. etc. but you aren't going to get much more than 185chp...

But this only applies to Max HP correct? I think what get's missed in these disccussions (N/A & turbo, and no this is not a new idea) on HP is everyone wants to talk about MAX HP. And while Max HP is good and so is increasing it, it shouldn't be the main measure for performance improvements. If 90% of your gains are in the upper rev range, 5,500+rpms for non-built motors, when are you using it? Motorsports competitors excluded.

Next time your out driving normally, how you drive 90+% of the time, pay attention to the rev range you drive in. I think I drive pretty aggresively most of the time, my range is 3,250 - 5,000 RPM's with spurts of 5-5,500 on certain tight back roads and I cruise at 3,750 about 95% of the time. And I pretty much downshift as soon as I drop below 3,000.

So how often are you actually using your Max HP in your normal driving? As I believe Pat mentioned, not quoting, look at your gains across the board not just the puny 11HP you gained at peak/max. All I'm saying is while the bolt on's may limit you to 185HP based on BSFC you could still see decent gains for daily driving. If I could get an extra 15 HP/TQ across the board from 3,000-5,000 I wouldn't car if my max HP stayed the same 5,500.

I say we need a new method for measuring the HP&TQ gains/losses for mods. Say maybe measuring the gain/loss every 250 RPM's across the dyno chart and coming up with a total. Just a thought.
SubaDuba420 is offline   Reply With Quote
Old 10-12-2006, 12:49 AM   #207
MeanEditor
Scooby Specialist
 
Member#: 123139
Join Date: Aug 2006
Chapter/Region: NWIC
Location: Oregon
Vehicle:
1993 Turbo L Wagon
RED

Default

After reading the berrywhirl that is this thread (and drinking a few beers in the process) I must say that there is alot of verbage over what is essentially 50hp at the most.

Our car (the ZtH car) is making some decent power and is pretty quick and to replicate it would cost a butt-load of cash as some of you have pointed out. Yes we have $2600 wheels, the first ones in the country I might add. But the Rotas we had before were just as round.

You will have to wait for the next issue to see what all the mods add up to, but it is impressive I must say.

In the end, mild bolt-ons will get you only so much. Maybe 20hp. Cams like the spicey cams might get you anouther 15-20 and EMS makes all these gains possible otherwise you might not get so much. We will continue to experiment and see what we can do about upping the top-end. (besides nitrous).

A good motor-build will cost a good amount. Balancing and blueprinting makes a big difference so this is not something to be ignored.

I guess my point is that it seems the path to a more sprightly motor is pretty well laid out. I think our car gives a good path to NA power, however, it comes at a price. The fact that making power costs a lot is nothing new. power=$$$ always has and with a 4 cylinder NA motor it takes a lot to make less and less power (law of diminishing returns).

The point of our build was to take everything to task and leave no stone unturned.

NONE OF OUR POWER FIGURES ARE ALTERED OR INFLATED

There is no gain on our side to inflate our figures and our modest gains reflect that. Anyone who thinks otherwise should think again. After all that has been put into our engine we are only bosting a bit over 50whp.

For over $11k in parts our project turbo 97 legacy will have a lot more power. That is the nature of the beast.

Ok I am drunk so hopefully what I have said helps. ZtH was meant to see what is possible and to experiment. We aren't trying to have the most HP or have the fastest car, it is a rolling laboratory. We hope it helps you with your own car.
MeanEditor is offline   Reply With Quote
Old 10-12-2006, 01:13 AM   #208
Back Road Runner
Scooby Guru
 
Member#: 60082
Join Date: Apr 2004
Chapter/Region: MWSOC
Location: Minnesota
Vehicle:
2004 Forester STI
Silver

Default

You're not drunk enough, your words are still legible.

Good points SubaDuba420. People tend to focus on the peak numbers but sometimes they forget about the area under the curve. I too would gladdly take a good chunk more area even if it drops my max HP down a notch.

Then some things we ignore, like rotating mass. It doesn't add HP, but it frees up some to be used elsewhere when we step on the gas. It doesn't come out in the numbers but you can feel it. Drivability, throttle response, heck, even gas milage are important in the end, all things we don't measure on the dyno but improve when we build up our cars.

Numbers are one thing. How well you enjoy the car at the end of the day is another.

Hey MeanEditor, would you guys consider your build to be to the point of a "race spec" engine? ...like, you'd find a comparable engine in a race level car.
Back Road Runner is offline   Reply With Quote
Old 10-12-2006, 10:23 AM   #209
Root Moose
Scooby Newbie
 
Member#: 8289
Join Date: Jul 2001
Vehicle:
1998 Impreza 2.5RS
Blue

Default

Quote:
Originally Posted by MeanEditor View Post
In the end, mild bolt-ons will get you only so much. Maybe 20hp. Cams like the spicey cams might get you anouther 15-20 and EMS makes all these gains possible otherwise you might not get so much. We will continue to experiment and see what we can do about upping the top-end. (besides nitrous).
This is consistent with my experience with other four cylinder makes/models.

In your opinion, what do you think would be the horsepower increase with modifying the cammed engine from being 87 octane friendly to 91-93 octane friendly?

I'm going to speculate 5-10 hp.
Root Moose is offline   Reply With Quote
Old 10-12-2006, 11:31 AM   #210
Matt Monson
Scooby Guru
 
Member#: 832
Join Date: Jan 2000
Chapter/Region: RMIC
Location: Teh Ghetto Garage, CO
Vehicle:
99 2.5RS, '85 911
'73 914 and 2012 BRZ

Default

Drunkeditor,
See, this is where I disagree with you and your ZTH project has actually helped to support my longheld opinions and what I have tried to "proove" with my own personal build. I too, was very deliberate in how I did my build and in what order things were done. What I am getting at is that for a couple of years now, I have told the members here that you don't have to break the bank to get some pretty serious gains on an NA Ej25. Part of that has been the argument that one doesn't need a build bottom end to get good sustainable power. When your magazine's car has a very expensive built bottom end with custom high compression pistons and it making almost identical power as my car, it tends to support my stance...
Matt Monson is offline   Reply With Quote
Old 10-12-2006, 12:01 PM   #211
MeanEditor
Scooby Specialist
 
Member#: 123139
Join Date: Aug 2006
Chapter/Region: NWIC
Location: Oregon
Vehicle:
1993 Turbo L Wagon
RED

Default

Matt,

I would like to compare our power delivery with yours. My bet is that we have more area under the entire curve and that our torque delivery is more constant. This is a function of our bottom end and maybe the port work.

If you have the latest issue handy, take a look at the entire graph, we are making more power everywhere, not just peak. I think that is the real difference. Our engine has a lot more grunt than it did before. It pulls all the way to redline... or our shift point rather.

Back Road: Yeah, I guess you could call this a "race-spec" engine. But this is open to interpretation. The balance and blueprinting is pretty common on racing machines but with our high compression I would say that it is definitely beyond the realm of "street"

Root: We have to run 92 (that is high-octane here in the NW) becuase of the high compression 12:1 basically. However, becuase we coated everything in ceramic we can get away with running pump fuel, without we would need to run 104 or something like that. Is it worth it? Yes, again I refer to our torque curve and the fact that both tq and hp curves have more area under the curve everywhere. As far as "converting" to high octane use, it is a function of higher compression. We have to. I would imagine that running high-octane in a stock compression car could help, but to really make use, you would want some tuning.
MeanEditor is offline   Reply With Quote
Old 10-12-2006, 12:09 PM   #212
Matt Monson
Scooby Guru
 
Member#: 832
Join Date: Jan 2000
Chapter/Region: RMIC
Location: Teh Ghetto Garage, CO
Vehicle:
99 2.5RS, '85 911
'73 914 and 2012 BRZ

Default

Compare away...



http://forums.nasioc.com/forums/show...highlight=dyno

There's no doubt that I could get more power from tuning, as my AF's in particular suggest so, but to claim that you have substantially more power under the curve doesn't hold water. I've been at this a long time. There's a reason that guys look to me for guidance on this stuff. I have done my homework and deliver the goods.

My car has the exact same cams and very similar headwork to your car. What I don't have is the $4000 block and a reflash...
Matt Monson is offline   Reply With Quote
Old 10-12-2006, 12:21 PM   #213
FalconRS
Scooby Specialist
 
Member#: 92913
Join Date: Aug 2005
Chapter/Region: W. Canada
Location: Winnipeg, MB
Vehicle:
2005 2.5RS Wagon
Crystal Grey Metallic

Default

I've got the magazine in front of me, and different dyno's aside...to me the torque curves between the tuned ZtH and Matt's car have the same basic shape. You can't really compare numbers directly because they are different dyno's, just overlay the curves one right on top of the other, the shape is very very close. Even the HP curve is similar, with the power jumping up significantly just past 4k.

Matt, what's your car got for EM?

EDIT: Interestingly, the "area under the curve" from 2500-3500 actually looks significantly healthier on Matt's car...that would be the daily-driving territory.
FalconRS is offline   Reply With Quote
Old 10-12-2006, 12:25 PM   #214
Matt Monson
Scooby Guru
 
Member#: 832
Join Date: Jan 2000
Chapter/Region: RMIC
Location: Teh Ghetto Garage, CO
Vehicle:
99 2.5RS, '85 911
'73 914 and 2012 BRZ

Default

Nada! That's a stock 2.5RS ECU running that thing.

And you are correct that you can't directly compare 2 different dynos, but you can make some speculation. On the dyno I tested on, stock RS's pull 95-100whp. So, I am seeing 50+whp gains, much like ZTH is. They may have a few whp on me, but the question one has to ask themselves is it several thousand dollars worth of power?
Matt Monson is offline   Reply With Quote
Old 10-12-2006, 12:27 PM   #215
FalconRS
Scooby Specialist
 
Member#: 92913
Join Date: Aug 2005
Chapter/Region: W. Canada
Location: Winnipeg, MB
Vehicle:
2005 2.5RS Wagon
Crystal Grey Metallic

Default

I'd like to see a 5th gear highway pull from 55mph-85mph or so, if I was a betting man, I'd take $10 on Matt.
FalconRS is offline   Reply With Quote
Old 10-12-2006, 12:37 PM   #216
Migo
Scooby Specialist
 
Member#: 81352
Join Date: Feb 2005
Location: Calgary
Vehicle:
2003 '03 EJ257 wagon
Green

Default

This thread just got loads more interesting.
Migo is offline   Reply With Quote
Old 10-12-2006, 12:49 PM   #217
Back Road Runner
Scooby Guru
 
Member#: 60082
Join Date: Apr 2004
Chapter/Region: MWSOC
Location: Minnesota
Vehicle:
2004 Forester STI
Silver

Default

A small reference to my '02 Forester, stock short I-Speed RS reflash, taken on a Dyno Dynamics awd dyno up in Minnesota on a cool(~60F), moist(sprinkled a tiny bit) day during a little MN Subaru dyno days event.

I plotted up a rough curve in Excel between the two, taking points at the marked rpms on the graph.

Edit: 4 cars, completely different dynos, so numbers aren't really directly comparable, plus or minus 10%, 15%, 20% etc... Feel free to interpret as you want. The graph includes my '02 Forester(completely stock with only I-Speed flash), Matt Monson's car, the Zth car, and Zzyzx's monster NA build.



I really like the low end grunt your car has. That must feel nice. The top end is equally good. Gains over mine were a consistant 15% to 20%. Of coures, this is a relative guage as the actual numbers aren't absolute. Take the comparison as a relative guage. As well, I-Speed rates their flash as +5 to 10HP over stock, so take that as you will. It is nice, feels more powerful everywhere, so gains are there, just not sure how much.

One things that really sticks out is that 3300rpm range. There's a good dip there. I know I-Speed was commenting on this early on in their developement of their reflash. It was something they noticed too, seemed to be purposely put in there, but they don't know why. Their initial work actually tuned that dip out and from the graph, you can see that area tuned right out and smooth(for the relatively low resolution of the plot ). I have a post over in the dyno sticky over in power bragging if anybody wants to look at my actual plots(last page of thread). I'm too lazy to plot this out in more detail, just wanted a quick and dirty comparison.

If you guys could figure out why that dip is there, you could really bump up your curve over that region. That's also about where peak torque is, so the boost in HP there may be significant.

Last edited by Back Road Runner; 10-12-2006 at 06:29 PM.
Back Road Runner is offline   Reply With Quote
Old 10-12-2006, 12:56 PM   #218
Back Road Runner
Scooby Guru
 
Member#: 60082
Join Date: Apr 2004
Chapter/Region: MWSOC
Location: Minnesota
Vehicle:
2004 Forester STI
Silver

Default

Just noticed your stock ECU comment. I can see some serious gains with a good tune. If you want something quick and dirty, just get a stock ECU flashed with I-Speed's SRS-20 flash. It's set up for intake/headers/exhaust and 91 octane. For how much you guys spent, $350 is a cheap try for more power. A version for cams should come out at some point in the near future, not sure when. It works up through '04, not sure what year your car is. Heck, give it a try just for fun.
Back Road Runner is offline   Reply With Quote
Old 10-12-2006, 12:59 PM   #219
Root Moose
Scooby Newbie
 
Member#: 8289
Join Date: Jul 2001
Vehicle:
1998 Impreza 2.5RS
Blue

Default

Quote:
Originally Posted by MeanEditor View Post
Root: We have to run 92 (that is high-octane here in the NW) becuase of the high compression 12:1 basically. However, becuase we coated everything in ceramic we can get away with running pump fuel, without we would need to run 104 or something like that. Is it worth it? Yes, again I refer to our torque curve and the fact that both tq and hp curves have more area under the curve everywhere. As far as "converting" to high octane use, it is a function of higher compression. We have to. I would imagine that running high-octane in a stock compression car could help, but to really make use, you would want some tuning.
Just for the sake of clarity, what I meant by converting for a certain octane is changing compression and dialing in the ECU as appropriate. AFAIK this is the only way to take advantage of higher octane short of ricer bench racing bravado.
Root Moose is offline   Reply With Quote
Old 10-12-2006, 01:02 PM   #220
FalconRS
Scooby Specialist
 
Member#: 92913
Join Date: Aug 2005
Chapter/Region: W. Canada
Location: Winnipeg, MB
Vehicle:
2005 2.5RS Wagon
Crystal Grey Metallic

Default

Pretty sure Monson doesn't need recommendations on mods for his car.

But you can't plot it like that, just overlaying them by the numbers...and did you take the chart Matt posted? Or the one from the Subiesport article? Because Matt's graph isn't the ZtH car, it's his own. Without delving back into the god-forsaken dyno debate, it just doesn't work that way. Same-dyno, same-day, that's the ONLY way you can directly compare. You CAN compare shapes of the curves, but that's it.
FalconRS is offline   Reply With Quote
Old 10-12-2006, 01:45 PM   #221
Back Road Runner
Scooby Guru
 
Member#: 60082
Join Date: Apr 2004
Chapter/Region: MWSOC
Location: Minnesota
Vehicle:
2004 Forester STI
Silver

Default

Hense, my clarification of that in my post.

Sorry, I wasn't paying attention to who posted what, in reference to Matt's car yes, I should grab the Zth car too...again, as you and I both stated, quite relative, but yes the curve can be compared, just not raw numbers. I'll change up the graph quick...
Back Road Runner is offline   Reply With Quote
Old 10-12-2006, 01:45 PM   #222
Matt Monson
Scooby Guru
 
Member#: 832
Join Date: Jan 2000
Chapter/Region: RMIC
Location: Teh Ghetto Garage, CO
Vehicle:
99 2.5RS, '85 911
'73 914 and 2012 BRZ

Default

You know, I really don't have a problem with people making suggestions. I just have no obligation to listen to their advice.

I considered the I-Speed reflash, and spent a good deal of time discussing with Bill Knose a custom map for my car. In the end, I decided it was good enough as is, at least for now. I have never held the goal of the highest HP streetable RS. What I value is good solid reliable power that is streetable. If you read my linked thread, you will see my emissions numbers from before headwork. I was 50 states emissions legal. I am getting my car smogged again in the next 2 weeks, but now with the headwork. We'll see if I can still fly under the radar or not post headwork...
Matt Monson is offline   Reply With Quote
Old 10-12-2006, 02:00 PM   #223
Back Road Runner
Scooby Guru
 
Member#: 60082
Join Date: Apr 2004
Chapter/Region: MWSOC
Location: Minnesota
Vehicle:
2004 Forester STI
Silver

Default

Ah, fixed, now all 3, just for reference. I was wondering why the Zth car was underinspiring.

Anywho, a rough comparison, give or take 10-15% Take it all with a grain of salt, but yeah, even with room for error, stock form gets stomped.
Back Road Runner is offline   Reply With Quote
Old 10-12-2006, 02:08 PM   #224
Back Road Runner
Scooby Guru
 
Member#: 60082
Join Date: Apr 2004
Chapter/Region: MWSOC
Location: Minnesota
Vehicle:
2004 Forester STI
Silver

Default

Ah...the times I love living in a state that doesn't care what comes out of your tailpipe.

Frankly, I didn't choose I-Speed for HP. I just hated the stock ECU, thought it was a bit crude and did weird things. It seemed like it got confused every time you moved the throttle. The reflash did wonders to smooth things out, get rid off all the goofiness that was the stock ECU, just a well refined product. To boot, you get slight gains all around which gives the car a little more pep everywhere from idle to redline. When I do my exhaust in the near future, I'll probably bump up to the SRS-20 flash.
Back Road Runner is offline   Reply With Quote
Old 10-12-2006, 02:21 PM   #225
Migo
Scooby Specialist
 
Member#: 81352
Join Date: Feb 2005
Location: Calgary
Vehicle:
2003 '03 EJ257 wagon
Green

Default

That's the torque graph? That is a very large contrast. I'd like to see what happens to this after Matt gets some headwork and EM.
Migo is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Build-up plans, please critique bongchild Normally Aspirated Powertrain 11 09-27-2005 03:25 PM
OT: Please Critique my resume DrDRum Off-Topic 25 07-20-2005 04:48 PM
Please critique this computer... GarySheehan Off-Topic 67 09-13-2004 06:40 PM
OT please critique my resume suprsubepower Off-Topic 17 03-23-2004 04:15 PM
IT/Developers please critique my resume maaw Off-Topic 9 08-22-2003 03:16 PM


All times are GMT -4. The time now is 06:12 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.