Road dyno after mods and a road tune

Phibs · Post by **Phibs** » Tue May 29, 2007 11:31 am

Mods:

Cobb TBE
Cobb Short Ram Intake
Custom road tune

Does anything look bad here and could I improve my numbers at all with say upgrading the fuel system? Odd that HP doesn't continue to rise and seems to flatten?

Post by **Sabre** » Tue May 29, 2007 11:51 am

Wow, there is a LOT of smoothing in that graph! Those are very respectful numbers. It's doubtful that you would see much benefit from an upgraded fuel system, but we also can't tell unless we have: Your AFR's (Air Fuel Ratio) and your IDC's (Injector Duty Cycle). How much boost are you running for those #'s?

sirwilliam · Post by **sirwilliam** » Tue May 29, 2007 11:51 am

By the graph, I am guessing Jeff tuned you up? How do you like it? The 2.5L are by nature torque monsters, especially when still utilizing the stock manifolds and turbo. I would rather have more torque. You can change how that looks by upgrading your turbo and/or changing to some aftermarket EQL headers.

drwrx · Post by **drwrx** » Tue May 29, 2007 11:54 am

Your numbers look very good. That is how most stage 2 STi dyno charts look. Without an air/fuel ratio or some kind of data-log to go along with the chart any other input we have will be guess work.

It should be said, that the vf39 just doesn't have much more to push past 6k RPMs. That is your limiting factor right now, not your fuel system. When you got your road tune did you see what your IDC (injector duty cycle) was? My guess is at this power level your around 90% or so.

If your looking for more power, w/o swapping injectors and fuel pump, consider either headers, alky injection or both.

drwrx · Post by **drwrx** » Tue May 29, 2007 11:55 am

Wow, we all chimed in at the same time didn't we?

zaxrex · Post by **zaxrex** » Tue May 29, 2007 12:01 pm

Without seeing the IDC or AFR logs, I can't say about your fueling.

Nice results for your mods, though.

zaxrex · Post by **zaxrex** » Tue May 29, 2007 12:03 pm

Ugh, got caught on the phone before I had a chance to submit my last post.

Is there a concensus here, or just an echo?

sirwilliam · Post by **sirwilliam** » Tue May 29, 2007 12:07 pm

Some things that would help:

-Upgraded fuel pump (Walboro or even better would be the stock supra fuel pump...pushes more fuel and is quieter than the Walboro but costs slightly more and you must modify the wiring a bit)
-Upgraded injectors (650cc or 740cc Deatschworks vs. stock 550cc)
-Larger turbo (would suggest FPGreen)
-Larger TMIC
-Aftermarket EQL headers
-Perrin EBCS

It really depends on what you want exactly. Power and mods are EXTREMELY addictive. Take your time and think about it. Changing your mind after a choice has been initiated can be costly.

sirwilliam · Post by **sirwilliam** » Tue May 29, 2007 12:09 pm

zaxrex wrote:Without seeing the IDC or AFR logs, I can't say about your fueling.

Nice results for your mods, though.

I am guessing at those numbers w/ the stock pump and injectors you are almost maxing (if not maxing out) the stock setup. I would guess that boost is probably around 18-20psi at the most and 15 at the lowest.

Phibs · Post by **Phibs** » Tue May 29, 2007 1:14 pm

sirwilliam wrote:Some things that would help:

-Upgraded fuel pump (Walboro or even better would be the stock supra fuel pump...pushes more fuel and is quieter than the Walboro but costs slightly more and you must modify the wiring a bit)
-Upgraded injectors (650cc or 740cc Deatschworks vs. stock 550cc)
-Larger turbo (would suggest FPGreen)
-Larger TMIC
-Aftermarket EQL headers
-Perrin EBCS

It really depends on what you want exactly. Power and mods are EXTREMELY addictive. Take your time and think about it. Changing your mind after a choice has been initiated can be costly.

Yes tune was from Jeff and I definitely plan on doing the upgrades you mention above. I basically want a fast spooling street car, no real plans to track it.

What larger TMIC is recommended ?
What about EQL headers ( and how much $ ? )
What does the EBCS do for me?

Jeff mentioned replacing my Cobb DP with a catless Cobb DP, is it really worth it and would anyone want to either trade or purchase my catted DP?

sirwilliam · Post by **sirwilliam** » Tue May 29, 2007 1:24 pm

Phibs wrote:
sirwilliam wrote:Some things that would help:

-Upgraded fuel pump (Walboro or even better would be the stock supra fuel pump...pushes more fuel and is quieter than the Walboro but costs slightly more and you must modify the wiring a bit)
-Upgraded injectors (650cc or 740cc Deatschworks vs. stock 550cc)
-Larger turbo (would suggest FPGreen)
-Larger TMIC
-Aftermarket EQL headers
-Perrin EBCS

It really depends on what you want exactly. Power and mods are EXTREMELY addictive. Take your time and think about it. Changing your mind after a choice has been initiated can be costly.
Yes tune was from Jeff and I definitely plan on doing the upgrades you mention above. I basically want a fast spooling street car, no real plans to track it.

What larger TMIC is recommended ?
What about EQL headers ( and how much $ ? )
What does the EBCS do for me?

Jeff mentioned replacing my Cobb DP with a catless Cobb DP, is it really worth it and would anyone want to either trade or purchase my catted DP?

There are a ton of different manufacturers making good TMIC out there. Best to do is get a good deal on a used one. As far as good ones: Perrin, Spearco, TXS, APS, etc....the list goes on and on. Just make sure you get a good seal from the splitter you are using w/ the new TMIC.

EQL is the same boat. There are many manufacturers and best to grab a set of used ones. Just do some research as to who is happy using what? I would try to spend as little as possible b/c they are pretty expensive for some and possibly get them coated (JETHOT!) if not at least wrapped.

You can can run the stock BCS or go w/ an aftermarket that will give you a little more control and faster spool up vs. the stock unit.

Your catted COBB DP should be easy to sell and I am sure there are people that would even trade w/ you. The COBB DP are a well made piece.

Phibs · Post by **Phibs** » Tue May 29, 2007 1:32 pm

sirwilliam wrote:
Phibs wrote:
sirwilliam wrote:Some things that would help:

-Upgraded fuel pump (Walboro or even better would be the stock supra fuel pump...pushes more fuel and is quieter than the Walboro but costs slightly more and you must modify the wiring a bit)
-Upgraded injectors (650cc or 740cc Deatschworks vs. stock 550cc)
-Larger turbo (would suggest FPGreen)
-Larger TMIC
-Aftermarket EQL headers
-Perrin EBCS

It really depends on what you want exactly. Power and mods are EXTREMELY addictive. Take your time and think about it. Changing your mind after a choice has been initiated can be costly.
Yes tune was from Jeff and I definitely plan on doing the upgrades you mention above. I basically want a fast spooling street car, no real plans to track it.

What larger TMIC is recommended ?
What about EQL headers ( and how much $ ? )
What does the EBCS do for me?

Jeff mentioned replacing my Cobb DP with a catless Cobb DP, is it really worth it and would anyone want to either trade or purchase my catted DP?
There are a ton of different manufacturers making good TMIC out there. Best to do is get a good deal on a used one. As far as good ones: Perrin, Spearco, TXS, APS, etc....the list goes on and on. Just make sure you get a good seal from the splitter you are using w/ the new TMIC.

EQL is the same boat. There are many manufacturers and best to grab a set of used ones. Just do some research as to who is happy using what? I would try to spend as little as possible b/c they are pretty expensive for some and possibly get them coated (JETHOT!) if not at least wrapped.

You can can run the stock BCS or go w/ an aftermarket that will give you a little more control and faster spool up vs. the stock unit.

Your catted COBB DP should be easy to sell and I am sure there are people that would even trade w/ you. The COBB DP are a well made piece.

Well I know there are good manuf, but how do I tell which is bigger and which will suit me?

Yeah I will put up a private for sale then. ANy concerns running catless?

sirwilliam · Post by **sirwilliam** » Tue May 29, 2007 1:42 pm

Phibs wrote: Well I know there are good manuf, but how do I tell which is bigger and which will suit me?

TMIC: Check to see what people are running, check all problems (long and short term) for all choices, see which ones fit better w/ certain parts, and go for cheapest in cost (not in quality). My buddy was getting good numbers from his HELIX TMIC while using an FPGreen. You can find those used for $300-400.

HEADERS: They are USUALLY all the same w/ some slight differences in the layout and coating. I really don't think spending $2000 for the higher end ones will make that much of difference to warrant that expenditure. I would go w/ one that people know works, makes good power, has little problems connected to it, and you can get used for cheap. The only downfall w/ the EQL headers is the loss of the boxer rumble. I would just stick to the stock manifold if you want to keep the boxer rumble...they have proven power up to 600WHP. I would keep the cost between $400-$700 for the EQL.

Phibs wrote:Yeah I will put up a private for sale then. ANy concerns running catless?

Yes.

First, environmentally it is bad.

Second, if the guy doing the inspection decides to do a physically look over all of your exhaust system, he can see that you don't have a CAT and can fail you.

Third, if you are at a light (w/ a catless 3" TBE) and a cop pulls up behind you, blazing him w/ a fireball puff when the light changes is not good...more noticeable at night.

Fourth, noise is dramatically enhanced. Makes it easier for cops to harass and ticket you.

Five, the smell can be bad, even in the car.

I think that is all...well all I can think of now.

Post by **Sabre** » Tue May 29, 2007 2:31 pm

Just a side note: Equal length headers WILL get ride of your boxer rumble and make your Subie sound like a Honda....

sirwilliam · Post by **sirwilliam** » Tue May 29, 2007 2:33 pm

Sabre wrote:Just a side note: Equal length headers WILL get ride of your boxer rumble and make your Subie sound like a Honda....

Hmm, where have I seen this statement...oh yeah, a couple posts up

sirwilliam wrote: HEADERS:...The only downfall w/ the EQL headers is the loss of the boxer rumble. I would just stick to the stock manifold if you want to keep the boxer rumble...they have proven power up to 600WHP. I would keep the cost between $400-$700 for the EQL.

Post by **Sabre** » Tue May 29, 2007 2:41 pm

lol....

Phibs · Post by **Phibs** » Tue May 29, 2007 3:59 pm

Hondas suck, keeping my rumble.

drwrx · Post by **drwrx** » Tue May 29, 2007 4:41 pm

As far as headers go, there are a number of ways to go:
1. Go cheap and grab a set of ebay "megan racing" type header/up-pipe combo for under $200. Just know you'll have to put in a ton of time and effort installing them, but they work!
2. Spend a bit more get a set of Gruppe-S headers for $379 or ceramic coated for $575.
3. Or drop some serious coin and get the best performance headers you can buy. The Perrin Equal Length Headers run about $750 but have the best gains of every header I've ever seen tested.

sirwilliam · Post by **sirwilliam** » Tue May 29, 2007 5:11 pm

Sabre wrote:

Okay Mr. 5,000 more posts in only one year

Phibs wrote:Hondas suck, keeping my rumble.

It will sound like a hooked up Porsche Boxster. Do you think Porsches suck?

Phibs · Post by **Phibs** » Tue May 29, 2007 5:25 pm

well that does sound better now that you mention it

And yes most porsches suck, in my rearview.

Does anyone else around here do a good tune like Jeff since he is moving to CA soon?

Post by **Sabre** » Tue May 29, 2007 6:26 pm

sirwilliam wrote:Okay Mr. 5,000 more posts in only one year

Even with 5000/yr, it's QUALITY vs quantity as some others on the boards.

sirwilliam · Post by **sirwilliam** » Wed May 30, 2007 7:24 am

Sabre wrote:
sirwilliam wrote:Okay Mr. 5,000 more posts in only one year
Even with 5000/yr, it's QUALITY vs quantity as some others on the boards.

Quality...Sure

just kidding

gsx-lex · Post by **gsx-lex** » Wed May 30, 2007 10:03 am

What type of dyno is this on?

sirwilliam · Post by **sirwilliam** » Wed May 30, 2007 10:14 am

gsx-lex wrote:What type of dyno is this on?

It isn't a dyno, just a pretty @#$% close estimate using software equations/formulas. And of course all dynos read differently.

Mr Kleen · Post by **Mr Kleen** » Wed May 30, 2007 10:55 am

yeah, all dynos read just a little differently. you can only really compare readouts from the same dyno. and remember: they're a tool for tuning not for bragging...