A few observations:
I just saw a header advertised and it touted the fact that the 2.5 inches
continued from the collector. I assumed this meant that it was a benefit.
I run a 2.5 inch pipe and then later on found that Jack Wheeler found this to
be the best diameter on a dyno...along with other variables. (Some day I hope
to try a chassis dyno....ideally before Walter Mitty)
There are so many tube benders out there, I eliminated the flex pipe a long
> I finally managed (with a little grinding) to run 2 1/2 inch flexible
> 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
> into one 2 1/2" collector with a bolt on piece that tapers down to two
> 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
> 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
> and hill climbing the car. This other guy, who traveled with us, had a
> new Alpha rated about 30 HP more than my old TR-3. He could beat my times
> 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
> It doesn't run very well and burns oil. I then beat his times in the hill
> 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.
> 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
> 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
> he had to do to install it. -- pull the transmission, install a TR-4
> and install the shorter starter motor.