Senior Tech Team
Join Date: Aug 2002
Location: Gold Canyon, AZ
Re: Questions on 2.5" vs 3" Exhaust
2.5" exhaust (head) pipes work very well with most street/strip applications with turbo-style mufflers and 2.5" or even 2.0" tailpipes. As the exhaust pulses enter the collector, from the primary tubes, a significant amount of velocity is lost. As the exhaust gases enter and exit from the turbo-style muffler, the velocity/pressure is further reduced. With straight through mufflers, a 3.0" exhaust system may (or may not) result very slight increase in horsepower - but the sound will be atrocious.
64 Chevelle Malibu Sport Coupe (original owner) car now has 427" BB, Jerico 5-spd. trans., Dana 60 rear end.
SAE Member (25+ years)
ASE Master Certified Engine Machinist
AERA Certified Professional Engine Machinist