pipe size

[sappy96]

Lets see, my GTO has dual 2.5 exhaust for a 400hp+hp car.
The aveo is about 1/4 of that w/ even less than 1/4 displacement. Sooo 2.5 is way to big.

This is actual math equations I am sure to figure out the optimum size of exhaust tubing.

Unfortunently it has more to do with displacement then with horsepower

Not really.
A turbo 4 cyl car can use a 3" exhaust.

[Aveo_Tuner]

2" 2" 2" 2" 2" 2" 2" 2" 2" 2" 2" 2" 2" 2" 2" 2" 2" 2" 2" 2" 2" 2" 2" 2" denis you have seen my car ive got a 2 inch dont go bigger

[aveodude]

Lets see, my GTO has dual 2.5 exhaust for a 400hp+hp car.
The aveo is about 1/4 of that w/ even less than 1/4 displacement. Sooo 2.5 is way to big.

This is actual math equations I am sure to figure out the optimum size of exhaust tubing.

Unfortunently it has more to do with displacement then with horsepower

Not really.
A turbo 4 cyl car can use a 3" exhaust.

Some even have a 4". But he is talking about N/A engines. The turbo provides all the backpressure needed. Hell, I have seen people go with a 4" downpipe straight to the ground. It helps spool the turbo.

[sappy96]

Ok a s/c.
The point I am making is that if you make more hp you need to flow more air and to flow more air you will make more hp until a certain point where the exhaust no longer is conducive to scavenging. Same thing w/ an intake. There is a tube for a reason. Open TB sucks for intake velocity.

[kirko]

Im running a 2.5" exhaust after the downpipe with a stock nissan resonator and a edelbrock sdt chambered muffler.