Bob Lang wrote:
[snip]
> The primary advantage to the expensive header is that the primary tubes
> are 1.5" OD - this is more than 1/4" larger than the other "quality"
> headers out there. The large tubes theoretically increase power.
[snip]
> The principle advantage of the expensive system is that the primary tube
> lengths are pretty close to ideal and they then add secondary tubes which
> was about the right length - so in theory you should get more power from
> this setup than you would get with the Monza header.
[snip]
As I understand it, the expensive s/s headers from TRF are reproductions of
the headers used by Group 44. They are mandrel-bent in the UK using very
accurate reproductions of the original jigs.
The Group 44 headers move the powerband significantly to higher rpm than
other headers currently available. I suspect that the builders of the repro
knew this, and attempted to shift the power-band to lower revs by using a
1 7/8" collector. I have this system, and I believe it works as intended,
but in my mind it does negate the advantages of using 1 1/2" tubing. I do
not have any dyno information to support this statement.
On a near-stock or mild motor, I doubt if you will notice any difference in
power over a cheaper header, but with a built motor and revised collector, I
would expect to see significant difference on the dyno.
Shane Ingate in Maryland
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