Stock Exhaust Limits

[JEDI]

Does anyone know the upper limits of the stock exhaust system for a GS-T? How much, or what can I do, before the stock system becomes too limiting.

Intake, BOV, Raise Boost a few pounds?

 

[Rob_DSM]

I'd be interested to hear some opinions on this as well.

 

[bwhite]

First off it never hurts to upgrade an exhaust system. In my opinion I think a stock system can be good for around 250-275 horsepower, and that may be pushing it. Off-road pipe and different muffler. Stock your already pushing 200 or more. You can get alot out of a stock turbo, but when you turn it up you got to have a place for all that to go. The exhaust is probably the first mod to do, along with hacking the air can and using a k&n and a manual boost controller. IMHO
If you want to upgrade the intake, turbo IC etc, you better run a larger exhaust and fuel system and something to control it all. Otherwise the mods are useless. This is just my opinion for what its worth. It all has to work together on both sides.

 

[ProjectTalon130]

Definitely do the exhaust before messing with the boost levels, the other 2 things (intake , BOV) should be OK to do. But as bwhite stated, you need a place for it to all go, if not you create unwanted backpressure within the motor and will eventual have major problems.

 

[Laser-man]

i have a gutted cat and removed muffler with a resinator tip, doesnt sound to bad, but it is kinda loud. it did the trick to get more flow till i can afford a real exaust.

 

[Rob_DSM]

That's about what I figured. I'm about to buy a full exhaust because I'm a little afraid of what that restriction could do to the engine at higher power levels.

In this book I've been reading off and on, the author talks about the exhaust gases not completely escaping the cylinder head if there's too much back pressure. I don't remember all of what I read, but I do remember that the lingering exhaust tends to heat the air in the chambers which leads to more detonation, I think. Anyhow, it does seem like a good idea.

How much difference does a cat-back and test pipe make if one were too cheap to buy the full system?

 

[will2shower]

it would all be depending on the system and what you do, such as no cat or a high flow. or just stock dp. But i think with a 2.5-3.0 " dp no cat, or high flow. and a 2.5-3.0 " cat back i would say maybe 15-20 hp.