Up until 1985, I also used a 2 1/2 inch pipe back from the header on my
SCCA EP TR-4 (per the Kastner 'bible'). When I put the engine on a dyno in
1985 we found an improvement by goung to a 3 inch pipe (this was the
largest diameter I could fit through the 'X' section of the TR-4A frame).
We also kept lengthening the pipe and kept getting better results with a
longer pipe. We finally put on a pipe that was basically the length of the
car, and found better horsepower at this length than any of the shorter
lengths we tried.
SO, I ended up using the same headers (Stahl), but installed a larger
collecter to tie into the 3" exhaust pipe, and I ran the 3" pipe as close
to the end of the car as I could get it (put a little turn-out on the end
for noise control).
Hope this helps, and good luck.
At 08:38 AM 3/1/99 -0500, you wrote:
> I have a friend here in Ft. Myers, Fl who owns a Dynojet Dyno and he had
>encouraged to put my TR4 vintage racecar on it.
>
> " After installing the long pipe (easy on the elevated Dynojet platform),
>my friend made a crayola line the length of the pipe.
>
> We wound up with a pipe that just did pass through the x opening in the
>frame and attached the turn down extension to it.
>
> All this for about $150 investment--the cheapest power you're likely to
>find.
>
>I hope this helps.
>
>Roger Beasley
>Cape Coral, Fl
>'62 TR4
>
>----------
>><matthews-home@worldnet.att.net>
>><susan@bearcom.com><fot@autox.team.net>
>> Subject: Re: Spit exhaust questions
>> Date: Saturday, February 27, 1999 8:30 PM
>>
>> Our spitfire currently has a pipe that stops just after the driver. However
>> we have been told by some more experienced folk who have raced spitfires
>> successfully in the past that they respond well to longer tail pipes. The
>> car originally had a full length exhaust that started in to a flat
>> megaphone just behind the driver and ended about a foot wide. We have seen
>> on other like this, the car was reputed to be ex group 44. We intend to go
>> back to the longer pipe when we get other problems sorted out.
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