Tips before racing at the track

[subiekillrGST]

Hey everyone, Iam going to the 1/4 mile raceway next week and I have a few questions. I have a 3 inch downpipe, and 2.5 inch cat back exhaust, and I was wondering would i benefit from removing my exhaust after the downpipe? I have stock fuel system right now, and i run 15psi, should i keep the boost at 15psi or turn it up for the track? And also, I have adjustable coilovers, and i was wondering if it would help to raise the rear up an inch or so? I hit 14.5 last time I ran with stock downpipe and cat, now iam hoping for low 14s. Thanks for the help.

 

[kelvinb]

i have a complete 3in turbo back with no cat, and ran without the catback for awhile (cut off after the doors) and it was actually slower. it sounds super sweet, but no performance increase for me

 

[danielbui]

don't raise it. traction will only get worse. get an alignment and adjust the camber on the camber kit adjusted to as straight as possible/ you do have a camber kit right?

 

[Burnett03]

i have a complete 3in turbo back with no cat, and ran without the catback for awhile (cut off after the doors) and it was actually slower. it sounds super sweet, but no performance increase for me

its all in your head

 

[Burnett03]

Hey everyone, Iam going to the 1/4 mile raceway next week and I have a few questions. I have a 3 inch downpipe, and 2.5 inch cat back exhaust, and I was wondering would i benefit from removing my exhaust after the downpipe? I have stock fuel system right now, and i run 15psi, should i keep the boost at 15psi or turn it up for the track? And also, I have adjustable coilovers, and i was wondering if it would help to raise the rear up an inch or so? I hit 14.5 last time I ran with stock downpipe and cat, now iam hoping for low 14s. Thanks for the help.

things were looking good until you said you had a 3inch downpipe to a 2.5 inch catback.. why would you create such a bottleneck?

 

[subiekillrGST]

Thanks for the replies. I bought the car with the 2.5 inch cat back exhaust, and Iam working on buying a new 3 inch cat back. I guess the best way is to keep the exhaust on, and keep my ride height where it is at. I hit 14.5 last time i went to the track, and that was redlining 3rd gear at the end of the track. Any reccomendations on what rpm to shift at in each gear. I know my T25 craps out at high rpms, so I dont plan on redlining 3rd next time I go.

 

[TurboDSM86]

Thanks for the replies. I bought the car with the 2.5 inch cat back exhaust, and Iam working on buying a new 3 inch cat back. I guess the best way is to keep the exhaust on, and keep my ride height where it is at. I hit 14.5 last time i went to the track, and that was redlining 3rd gear at the end of the track. Any reccomendations on what rpm to shift at in each gear. I know my T25 craps out at high rpms, so I dont plan on redlining 3rd next time I go.

a little off topic here, but what do you launch at in your GST?

 

[CanadianTSi]

I would think raising the rear would transfer more weight to the front which could only be a good thing...

As for where to shift, why not experiment. Try shifting at like 6k then 6.5 then 7 and see what happens to your times.

 

[subiekillrGST]

Last time I launched at like 3000rpm and dumped the clutch and i had a lot of wheel hop. I have falken azenis, and they grip pretty good. Any launching tips? I was able to pull my best 60' time of 2.29. I think Iam gonna try riding the clutch out at 3500rpm next time. I will experiment with the shift points, i was just wondering if anyone with a T25 found the best rpm to shift at.

 

[Waredtalontsi]

Raising the rear of the car about one and a half to two inches would increase traction, the reason is that the car has more wieght on the front and it won't squat as much during the launch. As far as shift points try shifting between 5.5K and 6K and see where the car feels faster.

 

[subiekillrGST]

Thanks, Iam gonna try raising it before I go to the track. Does anyone reccomend using racing gas. I can buy some at the pump, it's 100 octane. i heard it helps quite a bit, just want to know if I would benefit from it. And also is 15 psi the best for my stock fuel system or should i push it a little further? Thanks for the help.

 

[subiekillrGST]

Anyone reccomend running racing gas? I can get 100 octane at the pump, just wondering if it is worth using.

 

[Jahjahpoet]

Hey there.. I just filled my tank with Sunoco GT 100octane unleaded... my boost was set at 20psi.. I noticed that after the computer re did the fuel map automatically, it ran alot better.. smoother... and it pulled in the higher gears alittle stronger.. the revs seem to climb a little faster, cause the boost seemed to hit sooner... I had about a half a tank of this stuff without anything added... I lowered the boost to 15 to see how it would do with cooler air... compared to 94 octane at 15psi, I think that it pulled better in the top gears again... I also noted that I got a little better gas mileage with this stuff...Its great what you can do when your pulling higher timing... Expensive though.. If anyone is from Central PA, you can go to Sunoco in York *exit 19a* and pay 4.75 a gallon... There's my observations.. I'm sorry I didn't do any logs, but my cable is busted.. OF course, the results could have just been in my head, but I don't think soo.. then again.. I'm pretty crazy.. and it is 4:20am for me...

Gut your interior.. take out the backseats, spare tire, and subwoofers *if applied*... If you haven't already of course.. You can also unbolt your left headlight and remove it so you get nice cold air to your intake *if you have a short ram*... It's a pain in the butt, but could be worht the .3 seconds it saved me... Other than that, good luck buddy!