Quote:
Originally Posted by jhein
Interesting. Just out of curiosity, what do you think it would do with a 2.25 exhaust system?
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That would choke that size engine too much above 2500 rpm at full throttle. We discovered at the pure stock drags that the mandrel bent 2.5" exhaust systems from the manifolds (log & RA) to at least the tailpipes would greatly add to the power band for Pontiac 400's/455's of all stripes and reduce et's by .2 to .3 seconds (or more!) and add a 2-4 mph. So they are totally worth installing. The Pypes 2nd gen Firebird system with, or without, the X-pipe and the Race Pro transverse muffler is a great system. It does need tweaking to make it fit right (a little cutting and welding), but it's not leaving much on the table for a 450 hp engine with RA manifolds. If you are wanting 500+ HP, go with the 2.5" outlet manifolds and at least 3" headpipes/X-pipes to the mufflers.
Dennis