Mike,
I have to agree with Joe on this. Yes, the headers look cool but to me they
are not worth it. They are noisy, hot, and almost always leak. Working in an
auto parts store, I can't tell you how often someone comes in looking for
thicker gaskets or two sets to double up to fix leaks. I'm sticking with the
twin pipe cast manifold and adding a large single pipe system.
Last Fall I measured back pressure at the head pipes, below the manifold on
the late twin pipe exhaust. Naturally my readings don't reflect pressure
backed up in the manifold but from the manifold back there was barely 1LB of
backpressure at 5,000rpm. The gauge didn't even start to move off the pin
until 3500 rpm. Looks to me that the twin pipe system is pretty darn
efficient. I wonder if some of the noticeable power increase is more from
the sweet sound rather than less backpressure?
Same set up running a supercharger at 9lbs of boost showed 9lbs of
backpressure. I still haven't redone the piping yet but have just ordered a
2 1/2" Dynomax stainless muffler. Maybe next month's project.
Braced for flames-
Rick Patton
http://sidedrafttbi.com/index.htm
http://topshamautoparts.com/tr6/
> Mike, I spent an awful lot of money on a nice set of powder
> coated headers a
> couple of years ago. While I had no fitting issues ( you really
> do get what
> you pay for), I wish I'd spent the money elsewhere. I don't know that I
> recognized any "seat of the pants" difference in my modified
> engine with the header
> upgrade, except at rpms greater than 4500. The free flow
> exhaust by itself
> frees up a lot of HP. If I had to do it again, I'd have stayed
> with the cast
> manifold. (although the headers look cool with triple carbs)
> Joe Davis
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