Hi everyone, I'm barely making 400whp right now (tuned in hot weather in 91 octane it's cold as hell here and higher octane) with APS TT, 8.5psi, Unichip, and running richer than usual. However I have Kinetix Resonated 2.25" Test Pipes . . . . into 2.5" straight pipes (no cats, no mufflers). I was thinking maybe that was cutting off my flow, how much more power should I see with 3.5" test pipes?

 

It is not so much that they add power but they will allow the turbos to spool up quicker and you will have to keep an eye on the boost as it might want to spike a bit, but in th eend 8.5 is 8.5 and you will proably get same hp maybe more torque up front.

 

I have the Greddy TT w/built engine and found out tuning the 2,25" Injen exhaust backed up at 4500 RPM using 14psi boostand barely made 400Hp. I changed to 2.5 " APS exhaust , changed from Greddy e manage to HKS V-Pro EMS , changed 440 injectors to 850cc , added waste gates and now make 540HP. 550 Ft -lbs torque. I thought about going up to 3" APS exhaust , however, it was too loud for me . I set my target at 500 Hp but probably could get over 600 Hp with more boost.I believe the 2.5" exhaust is OK However, I found getting all the bits and pieces of the total system balanced was the key. Probably the VPro EMS was as much help as anything. I am very happy with my set up , however, so far I have torqued my half axles in two . and find my JWT heavy duty clutch ( Rated at 500Ft-lbs torque ) heats up after about 30 minutes on the track and can't change gears. So it's a never ending battle.

I would suggest getting some new half axes from the DRIVE SHAFT SHOP if you plan to run over 400Hp.and put some drag radials on at the drag strip.

 

I don't drag my car and I rarely take it to a road course. I have the JWT Heavy-Duty clutch.

450whp is about the MAX i want. Personally, 9.5 to 10psi is where I would feel safe with a stock motor and a good tune. I would probably have UTEC by then and AAM fuel-return system.

I understand balance is key, hence why I'm upgrading the Test Pipes, I feel they are too small and they are the most important piece, right after the Turbos.

Thanks

 

You need 3.5inch from the turbos back. a 3.5 inch going into a 2.5 inch pipe is still choking the turbo. You can add in 3.5 inch glass packs before the mufflers and it will not be horribly loud.

 

Not only to the larger pipes increase spool, trq, and whp...but they also reduce engine operating temps significantly, due to the reduced backpressure. So even if you dial the car back, you will end up with a safer 400whp. Hope that made sense.

 

I thought you totalled your Z last week?

 

Question for you guys, I have the fujitsubo catback which I know is not a true dual and is not good for the setup I have( I am working on that issue) now when I floor the car it gets up to 4k and then starts to stutter, I can not get past 4krpms, first I thought it was the clutch not holding the power but if that was the case then my clutchpacks would have gone within seconds (5AT) but now that I think of it this maybe back pressure stopping me from building power....could this be. I also have Crawford HF cats which again do not help the TT setup out.

 

You might check your cats. Pull em off and check the honey comb.

 

Yes. Yes I did. Now be quiet.

 

Dude get APS Test Pipes and Exhaust . . . . now.

 

Edit . . . wow.