Hello everyone, I have been a member with CL for a couple of months, but this is my first time posting something... So here's the deal I got a 01' GS430 and I have major issues with low end torque. It all started when I had a muffler shop make my exhaust from scratch, It starts after the o2 sensors, and it consists of 2.25' piping and a universal 2.5' x-pipe with straight 4' tips, no cats no mufflers... all I got is the cats up by the headers left. So once I had that done I immediatly felt the loss of torque... But it sounds incredible!!! So then I got the SRT HFI installed and it definatly made a difference but really in the higher rpm range. So at high speed my GS will spank all kinds of Mustang's, Camaro's, and even hang with a GTO, but yesterday I ran against a bone stock 04-05 automatic m3 and he beat me off the line and was ahead by about 1 car length but I finally caught up around 100-110 mph... The point of the whole story is my GS hauls *** from 80-140 but the 0-80 is disappointing... Is there anyone out there who knows of anything that can help my car kill that dam m3 when I get my rematch???

 

Hmmm....exhaust work only on a GS4XX will allow it to hang or beat an M3? That's pretty extreme! I have GS400 with an intake, exhaust, PI torque converter with a 2900 stall and a 3.76 TT rear and I will NOT be able to hang with an M3...at least I don't think I would be able to.

 

i think that you are getting a little bit confused. Although your car is fast, the race with an m3 is pointless from a dig since the m3 is probably on stick.

Second issue with you torque problem is probably the lack of back pressure. every car needs a certain amount of back pressure to achieve optimum output. Since you relieved all of the back pressure you increased you high end and decreased your low end. Go back to the muffler shop and see they have something that you can put in to increase back pressure and not lose sound

 

Less back pressure is always a good thing. What you need is exhaust velocity. Increasing the size of the exhaust means you're going to decrease the air velocity. But you do gain high end once your engine is able to pump out enough exhaust gas.

Most likely the intake isn't helping since the increase in intake size is also contributing to the decrease in intake air velocity. That explains why both mods do wonder at high speed, but not so well down low. In short of getting force induction or a higher stall torque convertor, our cars will be slow on the low end.

 

I wish it was true, but I don't care what exhaust and intake you have, no way a GS430 will hang with a gto or a LS1 camaro.

 

You need to get the car tuned with some kind of air fuel controller. That will bring out a few more ponies for sure. The SRT only compensates up to a certain point. With that big exhaust you will need a retune for sure. Oh yeah, and those guys must of been messing with you. No way a non boosted GS400/430 is gonna pull on LS1's or M3's. I got tired of getting beat so I slapped on a turbo. Now I'm the one that's 5-10 cars ahead on higway pulls

 

Agreed!!!!!!

 

A Rotrex superchager will fix your problem . Where are you located in TX? One of our client(Jeff Gordon), has a dual custom exhuast and it really improve the performance of his car.
JPI