Utec tuning with Crawford S2 in '02 WRX

[cegpcola]

I just got the car back together, and now it seems to run rich. I noticed that the car is turning around 11.5:1 AFR at 20% throttle. The car has a stutter when you go over that point. I need to see if anyone has a good MAP for the 2.5L swap with WRX heads.

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[nmyeti]

As I told you on the phone, the map is not really that different. We tuned a car with a 2.0L and an 18G. A few weeks later the customer decided that he wanted a 2.5L. The car came back to us with a 2.5L, same heads and the same turbo. The AFR of the map didn’t change a bunch between the two different short blocks. We had to make some adjustments to get the most out of the 2.5L block, but the car actually ran fine on the old map.

Your problem sounds like something mechanical.

-Nathan
www.turboxs.com

[hondaeater69]

Originally Posted by cegpcola

I just got the car back together, and now it seems to run rich. I noticed that the car is turning around 11.5:1 AFR at 20% throttle. The car has a stutter when you go over that point. I need to see if anyone has a good MAP for the 2.5L swap with WRX heads.

did you try leaning it out?

[mick_the_ginge]

Originally Posted by nmyeti

As I told you on the phone, the map is not really that different. We tuned a car with a 2.0L and an 18G. A few weeks later the customer decided that he wanted a 2.5L. The car came back to us with a 2.5L, same heads and the same turbo. The AFR of the map didn’t change a bunch between the two different short blocks. We had to make some adjustments to get the most out of the 2.5L block, but the car actually ran fine on the old map.

Your problem sounds like something mechanical.

-Nathan
www.turboxs.com

I'm tuned a UTEC map for my 2L setup with PE800 injectors and a GT30R. I have now swapped in a 2.5L block with heads and am able to run almost the exact same map. I had to add a little fuel in places but mostly it ran just fine.

Sounds like you have a mechnical issue. Maybe you are not running on all 4? Post turbo leak?

[TypeC]

Originally Posted by nmyeti

As I told you on the phone, the map is not really that different. We tuned a car with a 2.0L and an 18G. A few weeks later the customer decided that he wanted a 2.5L. The car came back to us with a 2.5L, same heads and the same turbo. The AFR of the map didn’t change a bunch between the two different short blocks. We had to make some adjustments to get the most out of the 2.5L block, but the car actually ran fine on the old map.

Your problem sounds like something mechanical.

-Nathan
www.turboxs.com

That's odd, I started with the base stage IV map with my hybrid and the timing was WAY off. We're talking 5-10 degs too advanced. I'm at 8.78:1 vs the standard 8.67:1, but that's not going to make that much of a difference.

The fuel map was fine though. The main problems (besides the timing) was that the 2.5 was reaching higher load, low rpm sites that the 2L can never hit. But that's my experience, YMMV.

And to the original poster, PM me your email and I'll gladly send you my street map (EJ257, WRX heads, VF39, 770 injectors). It should at least be a starting point.

[nmyeti]

Originally Posted by TypeC

That's odd, I started with the base stage IV map with my hybrid and the timing was WAY off. We're talking 5-10 degs too advanced.

Sounds like you have other problems. You shouldn't have to take more then 2 degrees out anywhere other then the mid-range where you might need another degree. 10 degrees of additional retard over the stg4 base map would put you at 15-11 degrees at 7000rpms.

-Nathan

[Javier]

Isn't all this really dependent on CR? One person's results being different could originate from different headgaskets or someone decking the heads, etc....

[nmyeti]

I seriously doubt anyone is running any significant boost on a higher compression motor then the one we have built for our shop car, and even that one at insane power levels for pump gas doesn't require that much timing retard.

Although there is a common mistake when people make the swap that could cause all sorts of issues with knock retard. The WRX UTEC’s knock thresholds are not calibrated to the STI short block. If you run the WRX thresholds, you’ll have some false knock issues.

[tmarcel]

Originally Posted by nmyeti

If you run the WRX thresholds, you’ll have some false knock issues.

Sooooo......what do you recommend? I've got mine at 3 (vs 2 IIRC which was the WRX UTEC param). I also decreased the values for rpm sensitivity. What's the solution?

[Javier]

+1 Natahn please fill us in. I just swapped in a crawford S3L and I'd love to know how I shoudl set the calibration...

[nmyeti]

Originally Posted by tmarcel

Sooooo......what do you recommend? I've got mine at 3 (vs 2 IIRC which was the WRX UTEC param). I also decreased the values for rpm sensitivity. What's the solution?

For an STI short-block, you should use STI sensitivity settings. Beyond that, you’ll have to attempt to calibrate the sensitivity on your own.

[cegpcola]

Ok so here is what I found. No Vac or boost leaks, which I new already because I went over those about ten times before I finished the install. I did pull one of the TGV Sensors off during the teardown, and when I reinstalled it, putting everything back together I did not preload the spring in it. Thus throwing the TGV code and sending the ECU into Limp mode. Just like that the problem is solved. The car runs great, although I have not seen any high RPM load points yet since I am still breaking in the new motor. I just got the car back together on Sunday, so I still have a while. I still want to see someones 2.5L Map(s), so I can see what they look like verses my modified stage four map. I have no doubt they are close, but I would like to see what others have done with their tunes.

[tmarcel]

Originally Posted by nmyeti

For an STI short-block, you should use STI sensitivity settings. Beyond that, you’ll have to attempt to calibrate the sensitivity on your own.

Nathan,

Thanks but more specifically, are you speaking of the rpm sensitivity areas or the threshold or both? Can you clarify?

Todd

[nmyeti]

Originally Posted by tmarcel

Nathan,

Thanks but more specifically, are you speaking of the rpm sensitivity areas or the threshold or both? Can you clarify?

Todd

The sensitivity numbers are the only ones that really change between the two platforms.

-Nathan

[cegpcola]

So what should the Sesitivity be at when running the STI block?

[TypeC]

Originally Posted by nmyeti

Sounds like you have other problems. You shouldn't have to take more then 2 degrees out anywhere other then the mid-range where you might need another degree. 10 degrees of additional retard over the stg4 base map would put you at 15-11 degrees at 7000rpms.

-Nathan

I'm running 16.5-17 deg from 5200 on. Clark (AZ) also suggests running ~17deg. Anymore and the car will knock. The motor was assembled perfectly. The block was decked .003" and the heads milled .006", netting 8.78:1 (STi gaskets). At torque peak I'm only running 13 degs. Hell, I might as well post my whole map!

Originally Posted by nmyeti

Although there is a common mistake when people make the swap that could cause all sorts of issues with knock retard. The WRX UTEC’s knock thresholds are not calibrated to the STI short block. If you run the WRX thresholds, you’ll have some false knock issues.

What is this common mistake? I have (MY THREAD WITH SPECRUM ANAYSIS ) have had a lot of issues with false knock. I just reduced the threshold on the top while logging the KS.

[cdvma]

Originally Posted by cegpcola

So what should the Sesitivity be at when running the STI block?

Have a look at the STi parameters file on the TXS website, its got them listed.

[nmyeti]

Originally Posted by TypeC

I'm running 16.5-17 deg from 5200 on.

Ignition timing should almost never flatten out like that unless for some reason your motor's VE is increasing as you approach redline. Given what I know about Subaru motors, I seriously doubt that's happening in your case.

As for your knock thresholds, it looks like your sensitivity may be too high, but I frankly haven’t looked at your thread too closely.

[SBW]

is the only real way to determine knock thresholds with the use of det cans and headphones?

[TypeC]

Originally Posted by nmyeti

The WRX UTEC’s knock thresholds are not calibrated to the STI short block. If you run the WRX thresholds, you’ll have some false knock issues.

Thank you! I switched to the STi thresholds and my 'knock' is gone! I'm still running retarded timing for the time being.

The STi thresholds are MUCH lower than that of the WRX (STi is 60 vs 80 at the last data point). I wonder if it's just a noisier engine.

[ride5000]

Originally Posted by SBW

is the only real way to determine knock thresholds with the use of det cans and headphones?

imo, yes.