1hotls1

iTrader: (6)

Can anyone tell me why a car may perform better with mufflers versus straight pipe? Considering this phenomenon, why use cutouts?

iamsickofitall

iTrader: (18)

it's all about backpressure...mufflers will create more backpressure and make your car feel more torquey and faster, but if you just have straight pipes/cutouts, you will gain more HP in the upper RPM's, but it may feel slower due to the lack of that torquey feel

and even with a cutout, some exhaust gases still go through the rest of exhaust system...it doesn't divert 100% of your exhaust

jmm98LS1

iTrader: (28)

No, it's all about velocity...not backpressure. The idea is to expel exhaust as quickly as possible, so you want to keep the exhaust hot and moving out fast. Too big of pipe and the exhaust cools and slows down. Pipe that's too small or mufflers that are restrivtive and there isn't sufficient flow. It's a balancing act between flow and velocity.

ChocoTaco369

you want 3 things with an exhaust setup:

1.) minimal backpressure. this yields the most hp.

2.) as high flow possible that the engine needs without losing torque

3.) the highest exhaust velocity attainable without sacrificing the minimum flow area the engine needs. this is produced by scavenging effects (x-pipe, y-pipe, h-pipe).

mufflers only restrict, they don't help. it's the piping that makes you faster. how to achieve the perfect setup is beyond you and me.

Camaro94SS

Perfect setup....Straight LTs....you'll be set, but with a few noise ordinances also

ChocoTaco369

actually you'll likely make more hp with an x pipe bolted on. the scavenging the x pipe provides will increase your exhaust velocity without restricting flow, therefore likely increasing hp

4mula

backpressure is a myth.
why do all top fuel cars and such run open headers if backpressure is needed.

Camaro94SS

lolol you'll get backpressure no matter what, 0 back pressure would be no exhaust manifolds AT ALL, straight headers still has backpressure, jsut minimal...which is why people do it...i dont think veterans at a track runnig straight headers would be to happy ahbout your statement of it being a myth....

4mula

let me restate, the least amount of backpressure is the best.
hence open headers.

98camaroLS1M6

iTrader: (35)

When you go with less backpressure, you will lose low end but gain top end that's how it works, same thing with a cam, sacrifice low end a little for more top end. Something has to give.