AMS's 05 STI Baselines and Tuning Results!!


After spending a few hours on the dyno getting acquainted to the stock ECU in the 05 STI we were able to make some changes and get some respectable numbers from it.

The car is COMPLETELY STOCK. Boost Peaks/Spikes to about 18 psi and drops to 14.5 psi by redline. The car is VERY consistent with only 1 or 2 hp/tq difference in between multiple dyno runs.

After adjusting timing, timing compensation, AVCS, air/fuel ratio, boost response, and wastegate duty, Martin and I were able to extract these results.

http://amsteam.net//files/3/AMSstockSTI2.JPG

For those of you who like to use alternate correction factors, here is a chart in
standard :)

http://amsteam.net//files/3/AMSstockSTI3.JPG

Written by Chris Black of AMS Performance

Eric

REALLY impressed with your guys EVO cars now i just cant wait to see what you guys do with an STi

yeah, do a GT42R sti!

very nice numbers....i can't wait to see what you guys do with suby's..

UPDATES:
05-21-2007

Well here is our 2005 Subaru STi. So far we really like the car and want to make it even better. Having come from the EVO world and making very fast drag and road race cars we think the Subaru’s are a solid platform.

http://amsteam.net/files/8/smallP4141836.JPG


We’ve done some baseline horsepower tests that show the motors strong potential

http://amsteam.net/files/8/stockdyno-1.jpg

If any of you are familiar with AMS then you know we take an engineering approach to modifying cars and evaluate it’s systems before making blind modifications. Part of this process is testing. We’ve outfitted our STi with a data logging system and will start implementing sensor to further test the performance of different components on the car. I’m very excited about this and I think everyone on here will love the data.
After the dyno testing I wanted to get some baseline runs at our local road course. Joliet Autobahn South course has a great mix of speed and handling and is quite technical. I took the STi in stock trim on 93 oct pump gas to the track to see what it could do. The modifications where Performance Friction 97 compound front & rear pads along with a good brake fluid flush with Wilwood EXP 600+. If I was to push the car I didn’t want to be babying the brakes the whole time. I also looked at the front suspension and noticed that the car had no negative camber. I loosened the offset bolt on the strut saddle mount and was able to get about 1-1.2 degrees of negative camber, which is still not nearly enough. I set the front toe to zero and off I went. With a full day of testing and getting comfortable with the track I was able to pull off a 1:39.36 hot lap and consistent high 1:40’x and low 1:41’x once the stock tires got greasy.

Here is the video link to the hot lap. It was the second lap out so the tires where still grippy and I had an M3 on R compounds to catch! The mic is built into the chasecam and it's in the center console so sound quality is poor.


:cool: http://media.ams-evo8.com/videos/amssti/amssubaru.mov :cool:


We're working on some packages for handling and power that will be track tested.


-Martin Musial

05-22-2007

Here is a screenshot from the Racepak GX2 system we're using

http://amsteam.net/files/8/GX2-STi-screen1.JPG

From the data I'm seeing sustained G's in the low 1.00-1.04 range and peaks as high as 1.20 but that's again, those are just peaks. Sustained G's of 1.00-1.04 is really good for street tires.

I've done some more testing already and with one change I picked up about about .03-.04 G's in sustained cornering, so about 1.03-1.07g's with a passenger in the car!

We'll have more data and video's coming soon.

05-29-2007

One of the first things we did to get more power is flash the STi.

We're using the COBB AP and also used ECU flash. Both work well but the AP has the ability for live tuning which is a quicker way of getting the car dialed in.

On the dyno we use a large fan in front of the car and a blower fan on the TMIC. The problem with the blower fan is that it sucks in hot air from the engine bay and blows it back onto the TMIC. What happens is that when the car is cold it makes about 10whp and 10ft-lbs more and then it heat soaks.


http://amsteam.net/files/8/Stock%20vs%20Flash.jpg


Peak power: 285 whp
Peak torque: 317 ft-lbs

http://amsteam.net/files/8/P5222226small.JPG

These runs are with the IC relatively cool and not heat soaked.

After the flash we wanted to try a cat-back exhaust. We had the car on a lift and after looking at the exhaust it seemed that most of the restrictions are in the downpipe and mid-pipe. We installed the cat-back and our suspicions were confirmed. Power gains were minimal and it was hard to tell if there was any gain at all!

Next step was a cold air intake. We did our research and went with the AEM CAI. After installation we made sure to keep an eye on the wideband in the car to see if A/F changed. Some of the power claimed by intake companies might come from the way the MAF pipe changes the A/F ratio. If the car was running 10.5:1 A/F and it runs 12.0:1 A/F after the intake then you’ll see a big power increase from that. Having said this we went into the test skeptical of any power gains.

We were pleasantly surprised that the A/F didn’t change at all after the AEM CAI installation and we saw decent power gains. Peak power went to 295whp (+10whp) and peak torque stayed the same. Even though peak power went up by only 10whp the power gains were an impressive 20whp at redline! :cool: Being a cold air intake the system breathes in ambient air and not hot under hood air.

I highly recommend against short ram intakes that pull in hot under hood temps, especially on a stock turbo. With under hood temps reaching over 150deg F you could be losing 20hp over a CAI. The difference might not be seen on the dyno since the hood is usually open anyways but will manifest itself on the street, track, or autocross. Having said that here is the dyno graph with the added AEM CAI.

http://amsteam.net/files/8/Flash%20Vs%20CAI.jpg

Sorry the dyno graph is in MPH as the ignition pickup wasn’t working correctly so we don’t have torque #’s or RPM.

NEXT: Stock TMIC testing & downpipe!

06-05-2007

Data AQ system is going in the car as we speak. I've got thin wire (quick reacting) Type-K thermocouples before and and after the IC and also in the intake. We've already done pressure drop tests of the stock IC with a very accurate Magnehelic pressure differential gauge.
I'll post up the file from the GX2 soon

06-12-2007

The next step in testing is to see what a downpipe would do.
We chose a turbo XS downpipe for the STi. Installation was easy and luckily all the bolts came loose. Seems like these cars are notorious for bolts that strip out or break on the exhaust system.

We also installed the Vibrant Cat-back exhaust on. On the dyno it made a good power gain and the spool up was much quicker. The RPM pickup was on the fritz so we didn't have rpm for this run. But according to the logs spoolup is about 400rpm quicker!! Peak power gains where not that significant but you can see that low and mid range power picked up significantly. These runs where made a 19psi. This is with no tuning just the parts changes

http://amsteam.net/files/8/DPTest.jpg


Next we installed a manual boost controller and dialed in about the same amount of boost. We got about 19.5 which is slightly higher than before. With a little bit of tuning this is what happened.

http://amsteam.net/files/8/DP%26MBC.jpg


Next up we test TGV deletes & try to squeeze 325whp out of it!

06-19-2007


So here we are. 328whp and 370ft-lbs on pump gas!!
since we last tested we did the TGV delete, turned the boost up to 21psi peak (drops to 15psi at high rpm) and dialed in the tune.

I have one very important thing to say about the stock ECU. Although it seems like a great ecu it will allow knock without actually pulling timing. I've seen the same thing with EVO ECU's. For some reason some ecu's will actually allow some knock events while other ecu's are over sensitive. I'm sure this has something to do with sensor tolerances and a slew of other variables. I've had some EVO's come in that where flash tuned by other vendors that were audibly knocking on the dyno and the ECU was not pulling timing! During tuning of our STi I actually heard a knock event and we had to back the tune down. It's rather surprising that the ECU didn't pick it up.

After many runs and dialing things back to where each run was very consistant you can see the results here.

http://amsteam.net/files/8/325whp-93oct.jpg

As you can see each run is almost identical to the next. The dynamic timing is still active in the ECU but the tune is dead on. There was a short interval between each run but the car was definitely heat soaked. The way we have our IC fan draws hot air from the engine bay and blows it back onto the IC. We're very impressed with the power and torque levels from the minimal mods.

I'll post up just the TGV delete results tomorrow along with our 100 octane tune....wait until you see the torque on that one!!

-Martin

06-26-2007

TGV Delete

http://amsteam.net/files/8/TGVDelete.jpg

As you can see the gains were mostly upon spool up and low to mid RPM range. Upper power really stayed the same.

Here is the 100 octane tune!!

http://amsteam.net/files/8/Stocktrubo100oct.jpg

I love the torque!!

While we're at it I'd like to try for the stock turbo record.

We did some prelim runs at the strip and on my second run I did a 12.5 at almost 110.X mph with a crappy 60' time. It's got a 12.2 to 12.3 in it the way it sits no problem. This car has about 40K miles and it's full weight with my 240lbs ass in it. With some tweaks and tuning I think mid 11's aren't out of the question :cool:

07-06-2007

We're stepping up the power!

We've installed a new test header to see what it would do. I didn't think it would make that big of a difference but the torque gains where huge. We lost a little bit of spool but the car spools so quickly anyway it's ridiculous.

343 whp and 402 ft-lbs of torque
Peak gains:
34 ft-lbs of torque
15 whp

This is on 93 octane and the only thing we had to change was to add fuel because it ran leaner with the header. Timing was the same and maybe a degree less in some areas! This is still on the stock fuel pump & injectors. A/F are in the 11.3-11.4 range under full boost. We'll be doing some longevity testing on the header with some heavy road course abuse coming very soon.

402 ft-lbs of torque on pump gas is awesome, I'm really liking this engine. With some future mods I think we'll be able to get 350-355whp on the stock turbo & pump gas.

http://amsteam.net/files/8/exhaust-1.jpg

07-23-2007

I took the Subaru to a NASA event at Joliet Autobahn this weekend. There good and bad things happened. First the car is an animal. On a pump gas tune it's making over 340whp and about 400ft-lbs of torque. The power made an incredible difference on track. My front end alignment setup added mechanical grip and the center diff sent a lot of power to the rear, this made for a fast and fun car. I could get into a corner and play with the power to keep the car very neutral.

Corner #4 on south track is a long and fast left hander where I needed to keep the car in 4th gear to in the power band so I could move the car with throttle. Now with over 140ft-lbs of torque gained I could leave it ni 5th gear no problem. I also noticed my exit speed improved by 3-5mph due to the camber change up front and what the power did to the balance of the car. When the car was stock it would hit 111mph on the back straight. Now I was approaching the braking zone and looked down at the speedo and saw 120mph before looking back up. I'd guess 121-123 when I got on the brakes.
With gobs of power I was looking forward to some killer lap times but I ran into a problem.

After my session I noticed some smoke out the exhaust. After parking the car I saw oil coming out of the boost control bleed hole, WTF? After sitting for a few minutes I started it up and saw fresh oil smoke come out the exhaust...great blown turbo! I was pretty upset because I signed up for the HPDE 3 and was going to get evaluated to be approved for my Time Trial liscence. My sales manager Eric Gaudi was kind enough to let me use his car for the testing but I really wanted to know why our turbo blew. The car has about 40K miles and it has had plenty of abuse so I wasn't too surprised. On the ride home the smoke susbsided quickly and everything was ok, again I was a little puzzled until we though about the PCV system. Either the PCV is bad or there is oil in that area when I'm under engine vacuum and it's sucking it right into the intake of the turbo. I know crawford makes a nice seperator and I'll have to look into that some more. Now that I think about it, every time I took the car to the road course I saw a little oil smoke after a session and the car sonsumed more oil than I thought it should, and only when road racing.

We'll get the issue fixed and get back to the track really show was the extra power does to lap time and track speeds. I think it would be cool to make a video of a side by side lap so you guys can see the difference.

BTW so far so good for the header, granted I only abused it for about 30 minuted on track but it's holding up so far. 30 minutes of track abuse is about 3 months of street driving :cool:

keep up the good work!! very interesting project you got going!!