I'm thinking of maybe buying a header tech header w/ merge collector which has transition pipe that flares out to 3". Would keeping 3" exhaust piping all the way through be too much for all motor setup? Or would it be recommended to get a 2.5" reducer and use 2.5" exhaust?

Jay Kim

 

been debating about this very thing now for quite some time... I would say reduce to 2.75 pipe and run from there... I think 3 is too big for NA. What HP are you going to be running? as that will make a difference in pipe size

 

I've actually seen a chart for exhaust tubing sizes based on single or dual ( true dual V config enines) and power level. Based on that, no you dont need 3". IMHO, 2.5" is the way to go.

 

From all I've read, 3" exhaust is too large for a light to mod bolt-on N/A car. I would not go any higher than 2.5" and even then would need to be a heavily modified car.