Jim, as a reference point, the most noticable change that I made some years
ago in my 3.5 TR8 was the addition of an off stock exhaust system beginning
with a set of Huffaker tri-y headers, the same headers that have been copied
and used by all the TR8 guys for years. The effect was quite noticable,
much more so than later added 4 bbl Holley. I can't speak to larger
versions of the engine with worked heads and cams. John Roper
Jim Stuart wrote:
> Mike-
>
> This a question most of us have faced in doing our conversions. Untill
> recently, we had one choice, the traditional headers originated in
> England by Ken Costello. These have been available from several sources
> in both mild & stainless steel. They are marginally better than the
> Factory cast iron manifolds, & not as likely to crack. Very restrictive,
> though, as you have noted.
>
> Several individuals have had custom headers made, or in a few cases,
> made them themselves. I have some pictures from a show about a year ago
> of some really outstanding home built, through-the-fender headers. This
> is part of the problem- THROUGH-THE-FENDERS. Most of us have shied away
> from cutting holes through, letting water in, etc. It is destructive to
> some degree, in the eye of the beholder. Without going through the
> fender, little or no improvement over the traditional header is
> possible.
>
> Enter the RV8. Now we have a factory header, that goes through the
> fender. Social acceptability. Real source. Something that can be copied
> at improved effectiveness or lower cost or both. The wave of the future.
> $500.00. Or more. Maybe less.
>
> Both Ted at TSI and Glenn Towrey are selling RV8 header copies. Choice
> of one piece stainless or two piece mild steel. The two piece can
> conceivably be installed with the engine in place, one piece certainly
> can not. While the 'RV8 style header may not be ideal, it is a big
> improvement over the traditional, in terms of performance. But, you have
> to cut those holes.....
>
> My personal opinion, just my opinion, mind you, please no flames, is
> that for a 3.5 engine with stock or mild street cam, you will not feel
> the difference in "the seat of your pants". Dyno tests will probably
> show an improvement, but you will not feel it unless you race & measure
> time in .001 seconds. Stay with the traditional headers, less work,
> fewer problems. 3.9 engine, high performance versions, you may be able
> to tell the difference, depending upon how experienced/perceptive you
> are. 4.2 street motor, also marginal. 4.2 or larger high performance
> need better breathing, go with the RV8. Gee Whiz Factor, you need the
> RV8 in polished stainless or high gloss ceramic RED.
>
> For myself, I am getting ready to install a 4.2 with a little more than
> just a street cam in my 3.5 GT. Problem is, I already have a new set of
> stainless headers installed on the present engine, & can't afford to
> spend $400-500.00 on new headers, & let the stainless just sit on a
> shelf. Ted, do you have a trade in policy?
>
> Ted, if you read this, send me a template/description of where to cut
> the holes. I may do the cutting while the engine is out, buy the headers
> later.
>
> Jim Stuart
> 2V8's, no dollars or sense
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