Bill, I read an article some where recently (may have been Hot Rod Mag online)
that was about headers and that the necked down header collectors were a good
thing. It helped with the exhaust pulse timing, I believe.
I have 2 1/2" pipe thru my crossmember. I only have about a 12" length of flex
between the header and the 2 1/2 to take up the engine movement. I have to run
a glass pack muffler to stay under the SCCA noise limits. Open exhaust puts me
very close and over depending on the weather. I did dyno testing with and
without a muffler 5 years ago and it did not have a measurable effect on power.
Tested the glass pack and a super turbo (which is even quieter). Joe(B)
-- WEmery7451@aol.com wrote:
I finally managed (with a little grinding) to run 2 1/2 inch flexible exhaust
tubing through the frame of the TR-3, as outlined in Kas's book. The dB's
went up from 88 to 95, but I have some after thoughts. The four tubes
terminate
into one 2 1/2" collector with a bolt on piece that tapers down to two inches
in diameter. I cut off the smaller diameter portion of this piece before
connecting the 2 1/2" exhaust tubing, since I thought that this was an
additional
restriction.
Could this tapered piece have something to do with the tuning of the exhaust
header? I got into tuned exhausts in the early 60's while still auto crossing
and hill climbing the car. This other guy, who traveled with us, had a brand
new Alpha rated about 30 HP more than my old TR-3. He could beat my times in
autocrosses, but then we went to the Lowellville Hill Climb. Prier to our
runs, he was telling me that there was something drastically wrong with my car.
It doesn't run very well and burns oil. I then beat his times in the hill
climb.
He took his car to Boffo Motors in Beaver Falls and told them that there was
something wrong with it. I beat his times in the hill climb. They told him
that his Alpha may have more rated power than my TR-3, but he has less
displacement. As a result, I probably have more torque for climbing hills. He
couldn't accept this explanation.
They also told him that he probably lost power if he took off his stock
exhaust system and added a straight pipe. This was supposed to be a tuned
exhaust
system.
I have another nearly identical exhaust header I can use. Someone was going
to put it on his street TR-3. He gave the header to me after I told him what
he had to do to install it. -- pull the transmission, install a TR-4 flywheel,
and install the shorter starter motor.
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