I was going to have an exhaust shop locally here fab me a "Y Pipe" for my Hooker 2460's. No one that I know of does mandrel bending. I've called tons of shops and all of them say "I don't know of any place that does mandrel bent exhaust". So what next. Am I really gonna notice the difference of mandrel bent vs. tradtional with the ripples? I know it creates more turbulance, but I'm only shooting for @ 300hp out of my 305.

Thanks for any input!!

 

The bad part about non mandrel bending is that it crimps the corners and makes them smaller, and a pipe is only as big as it's smallest point. So that expensive 3" pipe you just had them fab turns out to really be a 2.5" pipe because of the bends in it.

 

There is no doubt that a mandrel bends are better and less restrictive, but the pipes with crimped bends can still support a decent amount of power (will get more power obviously with smooth bends, though).

Last year I was running 13.2 @ 105 with my 350 LT1 with a small cam and heads with the following crummy exhaust:

Edelbrock TES headers (oval primary on a D shaped port head)

standard flow catco cat

2.75" OEM pipe for an IROC with crimped bends and a big crimp where it hops the axle

OEM style higher-flowing-than-stock muffler

OEM tailpipes for an IROC with crimped bends