phrkshw

so the new corsa comes in a 2.5in pipes setup - in the 500 rwhp area is 2.5in enough? i have been told 3in is really the only way to go when you get up in that HP range. true?

im going with a kenne bell and such later on - so she'll put out about 470rwhp to start. im just worried the 2.5in wont be able to breathe as well as needed.

any experience or opinions are welcome - thanks for the help!

Scooter80

If 2.5" ain't enough for you, you are sol. You'd have to go with a completely custom exhaust. I would think 2.5 is going to be fine though. Alot of guys oout there (including me) are supercharged with the 2.5. It is so free-flowing from the factory, I don't think you would notice much of a change to 3", though if you are looking for another dozen horses after the fact, I guess that could be your next project. I think you will need internals before 3" exhaust. Its a small motor, so I really don't think 3" is called for.
JMHO

classj

2.5 will be fine. No significant gains by going to 3" until you are closer to 600hp at the crank.

phrkshw

thats what i wanted to hear - thanks guys

bring on the kenne bell!

Sleeper05

i hope you are building the engine if you seriously intend to run 470rwhp...its fun to throw numbers around, but thats a lot

Tres Wright

3" pipes are a muffler shop's worst nightmare too. Try bending those suckers around an axle!!