Bad day at the track
11-09-2006, 05:13 PM
#1
Bad day at the track I made it to the track for the first time yesterday since I installed the STS turbo (18 months!). My best time was 13.364 @ 108.17 with a 2.2 60' time. 
I was hoping to be under 13, so I'm a little disappointed. Looks like if I get the launch better it should make 12's. The turbo seemed to be slow reaching full boost after launching, so I'm planning to wrap the exhaust with insulation to keep the heat in better. I also plan to replace the 2.73 gears with 3.42's. The motor and exhaust are completely stock, at least up till the turbo.
What sucks more than running slower than I wanted is that I got in a small accident on the way home. Several cars in front of me on an exit ramp slowed way down for no apparent reason, and then the guy in front of me slammed the brakes and came to a stop. I screeched the tires and could have gone around to the left, but there was another car there. I figured it's better to tag the guy from behind than side swipe someone, and the damage was pretty minor. His bumper has some scratches and slight dent, and my car just has some scratched paint by the passenger side headlight. The good part is that I was planning to re-paint the whole nose panel anyway, so this doesn't add much if any work for me. I just hope my insurance doesn't go up after his repairs. I need the money for more mods!
I was hoping to be under 13, so I'm a little disappointed. Looks like if I get the launch better it should make 12's. The turbo seemed to be slow reaching full boost after launching, so I'm planning to wrap the exhaust with insulation to keep the heat in better. I also plan to replace the 2.73 gears with 3.42's. The motor and exhaust are completely stock, at least up till the turbo.
What sucks more than running slower than I wanted is that I got in a small accident on the way home. Several cars in front of me on an exit ramp slowed way down for no apparent reason, and then the guy in front of me slammed the brakes and came to a stop. I screeched the tires and could have gone around to the left, but there was another car there. I figured it's better to tag the guy from behind than side swipe someone, and the damage was pretty minor. His bumper has some scratches and slight dent, and my car just has some scratched paint by the passenger side headlight. The good part is that I was planning to re-paint the whole nose panel anyway, so this doesn't add much if any work for me. I just hope my insurance doesn't go up after his repairs. I need the money for more mods!
11-09-2006, 06:10 PM
#2
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You really need to work on getting the motor breathing. Headers, exhaust. (these are the most vital) You need to get air flowing, because your way restricted at the moment. On the STS your intake is in the back underneath right?
It seems a gear change would help you get it spooling faster. This is an auto im assuming, get a stall!
Im sure your gonna see a dramatic improvement once you get the flow.
It seems a gear change would help you get it spooling faster. This is an auto im assuming, get a stall!
Im sure your gonna see a dramatic improvement once you get the flow.
11-09-2006, 06:30 PM
#3
Yeah, I realize that the stock manifolds are very restrictive, but I've read that headers can hurt the rear mount turbo in two ways. For one it creates more volume in the exhaust system and also dissipates more heat, which will cause more turbo lag. Yes, it's an auto, and I am considering a stall as well. With winter almost here I should have some time for projects.
11-09-2006, 09:31 PM
#6
No problems that I am aware of. The A/F was between 11 and 12 all the way through the runs. Maybe some knock retard? Another thought is that one of the cats is clogged. I had problems with cat overtemp protection kicking in under normal driving until I disabled it a couple months ago. I will say this, when it was dyno tuned, the spark advance tables were lowered down to 19-20 degrees at high rpm/MAP. I'm not sure if this was needed due to KR or if they just made it conservative since it's a stock motor on boost.
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11-10-2006, 08:27 AM
#9
Originally Posted by LT1MAN
you need at least a cat back, and some gears and apparently some better tires, with a 1.XX 60' you could be in the 12's with what you have now.
He has an sts turbo, there is no catback on the car... the turbo replaces it. 2.73 gears will help the turbo spool up fatser than 3.42's... the more load, the faster the spool. A stall will help get off the line and get moving. Do a search for "zombie" in the FI section here. He has documented gear changes, header versus manifolds, turbo sizing, and stall converters on his sts LS1 car.
Do you have the factory cats (or cat)?
11-10-2006, 01:39 PM
#10
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I wouldmgo with headers also. I know for a fact that all the guys that run the STS have headers fabbed up for their cars for this application. This will help you a lot.
Also get an LT4 knock module, your car may be reading a knock and adjusting timing to where it saves the motor.
Also get an LT4 knock module, your car may be reading a knock and adjusting timing to where it saves the motor.
11-10-2006, 05:03 PM
#12
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No to offend you but, Imo you should have done the supporting mods before you put the turbo kit on. Did you get a tune after you installed the turbo. Also it depends on you as well. Can you drive?
11-10-2006, 06:21 PM
#13
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Originally Posted by koolaid_kid
Something is wrong. You should be in the 12s with that boost.
11-10-2006, 08:26 PM
#14
I would say low 12's or better should have been expected especially with those numbers in your sig. My hotcam TA with 3.73's and all the other bolt ons netted it a high 12.
11-10-2006, 09:52 PM
#15
Plumber,
I figured I could install the turbo early on and get a big jump in performance with a lot less effort up front. I always planned to do supporting mods afterwards, but I thought taking the big step up front would make the car fun to drive right away. And yes, I had it dyno tuned at speed inc after the turbo was installed.
As far as my driving skills, this was only the 2nd time I've ever been to the track. The first time was two years ago when the car only had a CAI, and I ran 14.1@100 mph at that time. I don't remember what the 60' time was, but I don't think it was anything special.
In looking at the changes made to the tune, it looks like the spark advance was reduced significantly down to 19-20 degrees at high MAP/rpm. This could be part of why it seems to run weaker than expected. It may have been done to be conservative since it's 7 psi on a stock motor.
In any case, I've been planning a motor rebuild for boost, going to forged bottom end and lower the CR, etc. I even have a spare LT1 engine in my garage to work on in my spare time. More immediate mods will be gears for sure and maybe a stall and suspension. I'm still thinking things out.
I figured I could install the turbo early on and get a big jump in performance with a lot less effort up front. I always planned to do supporting mods afterwards, but I thought taking the big step up front would make the car fun to drive right away. And yes, I had it dyno tuned at speed inc after the turbo was installed.
As far as my driving skills, this was only the 2nd time I've ever been to the track. The first time was two years ago when the car only had a CAI, and I ran 14.1@100 mph at that time. I don't remember what the 60' time was, but I don't think it was anything special.
In looking at the changes made to the tune, it looks like the spark advance was reduced significantly down to 19-20 degrees at high MAP/rpm. This could be part of why it seems to run weaker than expected. It may have been done to be conservative since it's 7 psi on a stock motor.
In any case, I've been planning a motor rebuild for boost, going to forged bottom end and lower the CR, etc. I even have a spare LT1 engine in my garage to work on in my spare time. More immediate mods will be gears for sure and maybe a stall and suspension. I'm still thinking things out.
11-11-2006, 12:44 AM
#16
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I think it was good move to do that first and have the motivation to do supporting mods, which you'll then get huge gains from. I do think it's weird that you'll running 'slow' compared to having a turbo V8. I ran a 13.4 at 104 with intake, exhaust, and gear with my convertible, you should blow me away I would think
