Thread: Running Straight Pipe

Hello guys, another of those questions with mixed answers.

I wanted to know if running straight-pipe (cat delete and muffler delete), while keeping the resonator/glasspack, would affect our GTP on performance basis.

Some say that the Roots Blower on our supercharger create all the backpressure necessary for our engine and therefore everything after manifolds is restriction and for sound-purpose only. Removing mufflers and cat would actually increase horsepower on high Rpm range. A free flowing exhaust is key.

Others say backpressure is a must on every car and that they should all run with mufflers, even if it means low restrictions one. A car without mufflers would lose low-end torque and the exhaust valves could burn...

Just wanted to know your opinion, forget about the sound, just performance-wise.

I personnally removed the mufflers and saw a small difference in low-end torque...however, since headers apparently do the same (Yes, the powerband moves, no real torque is "lost") I guess a pulley drop would fix that.

Thanks for your time.

Unless you are making 400whp cat back changes will do nothing.

Horrible idea sound like poo. Stock catback wont change power until your above like 300whp or something like that

unless ur turbo'd keep the exhaust

It actually sounds really good with the glasspack, except when the engine is cold. I'm planning on getting some stainless mufflers to reduce drone on highway.

just get mufflers that are non restrictive if your worried about it... something that is just straight through wont have any restriction and will help in sound...

headers stock mufflers no cat and no res sounds pretty decent on my car, pretty much zero drone and barely any rasp..

Hey OP i have cat and muffler delete with a glasspack as well although im a GT.It sounds excellent at idle, beastly when i rev and very good when i go WOT...buttt cruisin blows sadly.too much drone especially at highway speeds.And yea once i removed my mufflers torque does seem to be taken away a lil.mufflers to come

Originally Posted by dmahlikGT

Hey OP i have cat and muffler delete with a glasspack as well although im a GT.It sounds excellent at idle, beastly when i rev and very good when i go WOT...buttt cruisin blows sadly.too much drone especially at highway speeds.And yea once i removed my mufflers torque does seem to be taken away a lil.mufflers to come

Same for me, drone is not so bad though!

This thread...

makes me...want to do this.

Don't do it, keep your stock exhaust. I regret not keeping mine, however I will be adding a 32" triple chambered Magnaflow resonator in replacement of my zzp exhaust's 12" single chambered Magnaflow. I will keep my fingers crossed this will stealth my car down quite a bit.

It will.

People have complained plenty about ZZP's catback being droney as ****

Originally Posted by bluegtp91

complained plenty about ZZP

= Nick

Says the guy with turbo whistlers on his exhaust tips and thought they cool...

I GOT YOU BRO

ha...keep going I have pictures

Originally Posted by bluegtp91

Says the guy with turbo whistlers on his exhaust tips and thought they cool...

I GOT YOU BRO

ha...keep going I have pictures

your never gonna let that go are you...

Originally Posted by gtpsleeper

your never gonna let that go are you...

Oh...and that certain race

Care for a rematch?

Originally Posted by bluegtp91

Oh...and that certain race

Care for a rematch?

very much want a rematch my friend!

Originally Posted by gtpsleeper

very much want a rematch my friend!

You gots mah digits foo