Stage1 06STI tuning diary

Guest_1u53r · 11-26-2006, 08:52 PM

Mid-November 2006:
Stripped off all the power mods from my STI that I could justify removing including:
-APS Catless R2 exhaust
-APS Header with APS Heatshields
-Typhoon Intake w/ better heatshield, bigger filter
-Cobb AP & StreetTuner

What is left, power-wise on my car is the following:
-APS Turbo Inlet Pipe
-Walbro Fuel Pump
-NGK LFR7AIX sparkplugs (one step colder than stock)
-Knife-edging/Porting and polishing of the IC inlet elbows, IC Outlet, and Throttle Body
-JDM IC Spray switch w/ Pressure-activated spray @ 13psi

Previously, this car dynoed at 321whp and 360lb-ft of torque. I was pretty impressed with its power but much annoyed by the 'ricer' noise of the car. I have grown decreasingly tolerant of any loud exhaust noise and my exhaust, as many will tell you, was not loud at all. The R2 is the quietest exhaust APS makes and the header just made it even quieter and this was still too loud. My first impression upon reverting to 'stock' was "ahhhhh silence" followed quickly by "hmmm there's no power below 4000rpm and not much above 5500".

So last week, I placed an order for a Tactrix cable and will be tuning it at roughly stage1 levels using Enginuity open-source software.

My main goals to start with are:
-adjusting everything to work properly with Virginia's E10 fuel
-improving boost response, especially down low
-overall flattening of the torque curve
-eliminating a couple nag features like the slam-shut throttle at 7000rpm and the initial IAM of 0.5.

Mechanically, my plans include some slight modifications withing the following restraints:
-no mod may increase sound levels or emissions. This means a STOCK exhaust and STOCK intake. My first candidate for improvement is more porting. I am most interested in doing a mild port and extensive polish on the exhaust manifold, as well as knife-edging the turbo inlet and outlet to gain precious efficiency.
-no mod may decrease efficiency, safety, reliability, or driveability.

I will update this as I go along, with road-dyno results at each step.

WolfPlayer · 11-27-2006, 09:22 AM

Any reason you don't want to install a catted downpipe and run it with the stock catback? The Cobb catted downpipe with the cast top section works very nicely with minimal sound increases (if that). Part of me REALLY wishes I was running a Cobb catted downpipe with the stock catback. So quiet.

Other things ...
1) Low restriction air filter (eh)
2) Better TMIC
3) GM boost solenoid

t

LOLSTi · 11-27-2006, 09:24 AM

Maybe some 6gun BJAs?

drees · 11-27-2006, 01:23 PM

Sounds like an interesting project. I too had a Prodrive oval tip on my wagon which is supposed to be one of the quietest axle-backs on the market, but also found it to be too loud, especially on long freeway trips. Having a wagon doesn't help, but now I have a STi axleback which is just about perfect.

I think that you are going to have a hard time making significant power with the primary downpipe cat still in the system. As Wolfplayer suggested, a catted downpipe or perhaps a shorty downpipe like the Crucial would really help with the expense of an increase in cold emissions, hot emissions shouldn't be significantly affected. (I personally wish someone made an affordable bellmouth shorty downpipe like the ScoobySport, heck, Helix can make a nice full-length DP for $199).

Besides that, I think that water injection would really help offset the backpressure caused the stock cats and let you increase boost/timing without detonation.

Guest_1u53r · 11-27-2006, 01:39 PM

The catted cobb downpipe is something I might consider in the future, but for now, I'm okay just with the stock setup. I'm not really looking to make a lot more power.... just trying to make better use of what's there. The biggest problem with stock mapping is that they bring boost on very late which destroys the 2500-3500 driveability.

thrlskr · 11-27-2006, 02:32 PM

WolfPlayer-

What advantage does the GM Solenoid offer at this level. I searched but nothing useful came up. I used a GM Solenoid on my Turbo Miata, but it was more of a price point decision than a absolute performance decision.

crystal_Imprezav · 11-27-2006, 04:24 PM

It helps a great amount in achieving target boost in lower gears such as 1st and 2nd. It also allows way more head room to make more boost up top where the factory solenoid will not hold more that 15psi (16psi easy with the Perrin I have). Along with that it gives you more headroom with WGDC where before I was running 80-90% to make 20-21psi and now I am more around 55% and making 22-23psi. My stock solenoid sucked in 5th gear where it was bleeding way too much air to the WG and it was fluttering and getting osilating boost which was horrible and annoying. The EBCS is one of the best mods IMO being that I am trying to run as much boost as I can on the stock turbo and meth. On just pump gas, the stock unit worked just fine and never had problems with 18-20psi.

Nhlurh, have you considered running the Stealthback again with the stock axleback. I really liked that setup for the noise level and still gained all the low end that I desired. As for other mods that will satisfy your stock like needs, how about some TGV deletes, P&P stock headers, and maybe WI to run the car safer with its knock resistance. Running straight water allows you to maybe add some more DA save some gas, make up for the crappy e10, and best of all it requires very little tuning if just water is injected. If the unit ever failed, by just adding DA the ecu should be able to pull any unsafe additional timing like a self fail-safe.

JJ18Sniper · 11-27-2006, 04:36 PM

Quote:

Originally Posted by WolfPlayer

Any reason you don't want to install a catted downpipe and run it with the stock catback? The Cobb catted downpipe with the cast top section works very nicely with minimal sound increases (if that). Part of me REALLY wishes I was running a Cobb catted downpipe with the stock catback. So quiet.

Other things ...
1) Low restriction air filter (eh)
2) Better TMIC
3) GM boost solenoid

t

Very interesting idea on the Cobb downpipe with the stock catback Wolf... I wonder how much of a "bottleneck" would exist. I doubt the cat vs. catless would be the bottleneck of the exhaust... but moreso the catback region.

WolfPlayer · 11-27-2006, 04:53 PM

Quote:

Originally Posted by JJ18Sniper

Very interesting idea on the Cobb downpipe with the stock catback Wolf... I wonder how much of a "bottleneck" would exist. I doubt the cat vs. catless would be the bottleneck of the exhaust... but moreso the catback region.

I know that nhluhr is not going to go with an upgraded turbo and obviously he isn't looking at making any serious power (because he parted his car out). Thus, I think the Cobb catted downpipe makes a lot of sense. I bet with just the catted downpipe and the stock catback he can make 280-290whp.

t

WolfPlayer · 11-27-2006, 04:55 PM

Quote:

Originally Posted by thrlskr

What advantage does the GM Solenoid offer at this level

Crystal_imprezav covered it. My suggestion is simply because it's cheap and it will allow him to hold boost better up top.

t

***Tomerville*** · 11-27-2006, 05:04 PM

I like the sounds of this project. In a sense it's a magazine worthy project considering you are taking the stock car, and showing how much Subaru leaves on the table.

If the car dynos ~260, and Wolf thinks nhl can get ~280, that's a solid improvement (obviously) for a car with basically no aftermarket modifications.

Good luck, can't wait to see the results.

Guest_1u53r · 11-27-2006, 05:31 PM

It had occurred to me that I want to try to get as much performance out of the car with absolutely 0 impact on driveability or civility. I've just searched and found Aaron's dyno test of the STI muffler.... it's self-explanatory. He took a stage2 (with stock muffler) car, reset the ecu, then started doing dyno runs. Then took the muffler off, reset the ecu, and did dyno rusn. These are the two last runs of each set.

This tells me that even on this catless stage2 setup, the muffler is *almost* no restriction at all. So I definitely don't need to deal with any increased noise levels. A Catted Cobb downpipe with stock catback would be great, IMHO.... super quiet, decent emissions, and powerful enough.

I am also trying to do the same thing with my suspension setup, but that's another story entirely.

kts262 · 11-27-2006, 05:52 PM

Quote:

Originally Posted by crystal_Imprezav

Nhlurh, have you considered running the Stealthback again with the stock axleback. I really liked that setup for the noise level and still gained all the low end that I desired.

I was also going to suggest a catted downpipe or TXS Stealthback for a bit more power w/o the noise. I loved the extra power I got from my Stealthback and it was nice having a car that wasn't that much louder than stock.

If you want to try out a Stealthback I have my old one I just put up for sale. I'll make you a hell of a deal if you're interested....

crystal_Imprezav · 11-27-2006, 08:11 PM

Quote:

Originally Posted by nhluhr

I am also trying to do the same thing with my suspension setup, but that's another story entirely.

I can get these parts off your hands

Guest_1u53r · 12-02-2006, 11:31 PM

ok so I got my Tactrix cable and flashed on a basic map to start with.

I started with the stock map and made the following changes:
-Boost Targets flattened from 3200 to 6900 (still a very mild ramp up and taper of about 1/2 psi)
-WGDC increased to match the above changes
-open loop fueling leaned by 0.1 AFR to cover most of the WOT range
-initial IAM of 1.0
-Checksum fix enabled
-Injector scaler set to ~485 to compensate for E10 fuel
-LowSpeedBoost set to +3% instead of the -% and 30mph
-TDC table last row bumped up to just barely below the 6700 row to reduce the 'throttling' at high rpm
-Rev limit changed to 7000/6950
http://wrx.dicknogs.net/tuning/opene...ti_working.hex

The results are a very slight improvement from stock in terms of throttle response from lower rpms, but there seems to be a 'hole' in the upper rpms where it feels like it stutters. I need to do some logging to figure it out...

Also, looking to get ahold of the timing and fuel tables for AP-stage1 from somebody who has a StreetTuner...

11-26-2006, 08:52 PM	#1
Guest_1u53r Banned Fav Mod: knowledge Location: Bristow, VA Posts: 392 Join Date: Apr 2003 Trader Rating: (1)	Stage1 06STI tuning diary Mid-November 2006: Stripped off all the power mods from my STI that I could justify removing including: -APS Catless R2 exhaust -APS Header with APS Heatshields -Typhoon Intake w/ better heatshield, bigger filter -Cobb AP & StreetTuner What is left, power-wise on my car is the following: -APS Turbo Inlet Pipe -Walbro Fuel Pump -NGK LFR7AIX sparkplugs (one step colder than stock) -Knife-edging/Porting and polishing of the IC inlet elbows, IC Outlet, and Throttle Body -JDM IC Spray switch w/ Pressure-activated spray @ 13psi Previously, this car dynoed at 321whp and 360lb-ft of torque. I was pretty impressed with its power but much annoyed by the 'ricer' noise of the car. I have grown decreasingly tolerant of any loud exhaust noise and my exhaust, as many will tell you, was not loud at all. The R2 is the quietest exhaust APS makes and the header just made it even quieter and this was still too loud. My first impression upon reverting to 'stock' was "ahhhhh silence" followed quickly by "hmmm there's no power below 4000rpm and not much above 5500". So last week, I placed an order for a Tactrix cable and will be tuning it at roughly stage1 levels using Enginuity open-source software. My main goals to start with are: -adjusting everything to work properly with Virginia's E10 fuel -improving boost response, especially down low -overall flattening of the torque curve -eliminating a couple nag features like the slam-shut throttle at 7000rpm and the initial IAM of 0.5. Mechanically, my plans include some slight modifications withing the following restraints: -no mod may increase sound levels or emissions. This means a STOCK exhaust and STOCK intake. My first candidate for improvement is more porting. I am most interested in doing a mild port and extensive polish on the exhaust manifold, as well as knife-edging the turbo inlet and outlet to gain precious efficiency. -no mod may decrease efficiency, safety, reliability, or driveability. I will update this as I go along, with road-dyno results at each step. This ad is not endorsed by this member. Please register or login to hide this ad. Last edited by nhluhr : 11-26-2006 at 08:55 PM.

12-02-2006, 11:31 PM	#15
Guest_1u53r Banned Fav Mod: knowledge Location: Bristow, VA Posts: 392 Join Date: Apr 2003 Trader Rating: (1)	ok so I got my Tactrix cable and flashed on a basic map to start with. I started with the stock map and made the following changes: -Boost Targets flattened from 3200 to 6900 (still a very mild ramp up and taper of about 1/2 psi) -WGDC increased to match the above changes -open loop fueling leaned by 0.1 AFR to cover most of the WOT range -initial IAM of 1.0 -Checksum fix enabled -Injector scaler set to ~485 to compensate for E10 fuel -LowSpeedBoost set to +3% instead of the -% and 30mph -TDC table last row bumped up to just barely below the 6700 row to reduce the 'throttling' at high rpm -Rev limit changed to 7000/6950 http://wrx.dicknogs.net/tuning/opene...ti_working.hex The results are a very slight improvement from stock in terms of throttle response from lower rpms, but there seems to be a 'hole' in the upper rpms where it feels like it stutters. I need to do some logging to figure it out... Also, looking to get ahold of the timing and fuel tables for AP-stage1 from somebody who has a StreetTuner... This ad is not endorsed by this member. Please register or login to hide this ad.

11-27-2006, 09:22 AM	#2
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,622 Join Date: Jun 2004 Trader Rating: (6)	Any reason you don't want to install a catted downpipe and run it with the stock catback? The Cobb catted downpipe with the cast top section works very nicely with minimal sound increases (if that). Part of me REALLY wishes I was running a Cobb catted downpipe with the stock catback. So quiet. Other things ... 1) Low restriction air filter (eh) 2) Better TMIC 3) GM boost solenoid t

11-27-2006, 09:24 AM	#3
LOLSTi S204 Racer Car: RIP 02 WRX Fav Mod: 2004 Aspen White WRX STi Location: Cincinnati Posts: 3,621 Join Date: Dec 2005 Trader Rating: (1)	Maybe some 6gun BJAs?

11-27-2006, 01:23 PM	#4
drees STI Driver Car: 03 Subaru WRX wagon Fav Mod: Tuned by Enginuity Location: San Diego Posts: 223 Join Date: Aug 2005 Trader Rating: (0)	Sounds like an interesting project. I too had a Prodrive oval tip on my wagon which is supposed to be one of the quietest axle-backs on the market, but also found it to be too loud, especially on long freeway trips. Having a wagon doesn't help, but now I have a STi axleback which is just about perfect. I think that you are going to have a hard time making significant power with the primary downpipe cat still in the system. As Wolfplayer suggested, a catted downpipe or perhaps a shorty downpipe like the Crucial would really help with the expense of an increase in cold emissions, hot emissions shouldn't be significantly affected. (I personally wish someone made an affordable bellmouth shorty downpipe like the ScoobySport, heck, Helix can make a nice full-length DP for $199). Besides that, I think that water injection would really help offset the backpressure caused the stock cats and let you increase boost/timing without detonation.

11-27-2006, 01:39 PM	#5
Guest_1u53r Banned Fav Mod: knowledge Location: Bristow, VA Posts: 392 Join Date: Apr 2003 Trader Rating: (1)	The catted cobb downpipe is something I might consider in the future, but for now, I'm okay just with the stock setup. I'm not really looking to make a lot more power.... just trying to make better use of what's there. The biggest problem with stock mapping is that they bring boost on very late which destroys the 2500-3500 driveability.

11-27-2006, 02:32 PM	#6
thrlskr The Next Petter Solberg Car: 05 WRX STi Fav Mod: Seat Time Location: San Diego, CA Posts: 916 Join Date: Mar 2005 Trader Rating: (4)	WolfPlayer- What advantage does the GM Solenoid offer at this level. I searched but nothing useful came up. I used a GM Solenoid on my Turbo Miata, but it was more of a price point decision than a absolute performance decision.

11-27-2006, 04:24 PM	#7
crystal_Imprezav Spec C Club Car: Slow 05 STi Fav Mod: Loping Idle Location: Chewy's Garage Posts: 1,862 Join Date: Mar 2005 Trader Rating: (11)	It helps a great amount in achieving target boost in lower gears such as 1st and 2nd. It also allows way more head room to make more boost up top where the factory solenoid will not hold more that 15psi (16psi easy with the Perrin I have). Along with that it gives you more headroom with WGDC where before I was running 80-90% to make 20-21psi and now I am more around 55% and making 22-23psi. My stock solenoid sucked in 5th gear where it was bleeding way too much air to the WG and it was fluttering and getting osilating boost which was horrible and annoying. The EBCS is one of the best mods IMO being that I am trying to run as much boost as I can on the stock turbo and meth. On just pump gas, the stock unit worked just fine and never had problems with 18-20psi. Nhlurh, have you considered running the Stealthback again with the stock axleback. I really liked that setup for the noise level and still gained all the low end that I desired. As for other mods that will satisfy your stock like needs, how about some TGV deletes, P&P stock headers, and maybe WI to run the car safer with its knock resistance. Running straight water allows you to maybe add some more DA save some gas, make up for the crappy e10, and best of all it requires very little tuning if just water is injected. If the unit ever failed, by just adding DA the ecu should be able to pull any unsafe additional timing like a self fail-safe.

11-27-2006, 05:04 PM	#11
*Tomerville* Likkle Jacob Car: '06 STI Fav Mod: AVIC D-3 Location: Too many places. Posts: 1,116 Join Date: May 2006 Trader Rating: (5)	I like the sounds of this project. In a sense it's a magazine worthy project considering you are taking the stock car, and showing how much Subaru leaves on the table. If the car dynos ~260, and Wolf thinks nhl can get ~280, that's a solid improvement (obviously) for a car with basically no aftermarket modifications. Good luck, can't wait to see the results.

11-27-2006, 05:31 PM	#12
Guest_1u53r Banned Fav Mod: knowledge Location: Bristow, VA Posts: 392 Join Date: Apr 2003 Trader Rating: (1)	It had occurred to me that I want to try to get as much performance out of the car with absolutely 0 impact on driveability or civility. I've just searched and found Aaron's dyno test of the STI muffler.... it's self-explanatory. He took a stage2 (with stock muffler) car, reset the ecu, then started doing dyno runs. Then took the muffler off, reset the ecu, and did dyno rusn. These are the two last runs of each set. This tells me that even on this catless stage2 setup, the muffler is almost no restriction at all. So I definitely don't need to deal with any increased noise levels. A Catted Cobb downpipe with stock catback would be great, IMHO.... super quiet, decent emissions, and powerful enough. I am also trying to do the same thing with my suspension setup, but that's another story entirely.