I had a pretty interesting discussion with Neil about the differences between the rev and torque pipes - and wow, what an eye opener! My original info was close, but not completely correct. It's good to get the skinny straight from the designer. Most of my info had come from Don - who wasn't involved in the development of the pipes like Neil and Jay were.
Rev and torque pipe - the names are very misleading - it came from necessity of advertisement years ago when they developed the pipes and started selling them. "We had two pipes and didn't know exactly how to label them."
The two designs were set about the rev limiter and/or lack of rev limiter. Stock Pilots rev to 7,000 - 7,300 rpm before the rev limiter kicks in. Neil said that the CDI's seem to vary a touch on the cut off point, so he says, in general, that the rev limit is 7,200 rpm. (I was told 6,800 - 7,000 years ago - was wrong)
Torque Pipe:
This pipe was designed for performance gains using a STOCK or near stock jug and head and a STOCK CDI. It peaks out about 7K, giving a good broad power band up to that point. It comes into the meat of the band about 6,500 and signs off about 7,200.
Rev pipe:
This pipe was developed for the performance setup jugs. Ported! It was also designed to be used with an engine that has a modified rev limiter (no limit). This pipe works best between about 7,000 and 8,000 rpm.
The output curve on the dyno between the two pipes is very similar - with the Torque pipe having a bit more low end and the Rev pipe having better top end performance (where the names ended up coming from), but they are actually quite different animals and designed to be more specific to the engine modifications used.
I also asked why the rev pipe was two pieces and was quite surprized by the answer.
It wasn't a vibration issue at all (as I was told a long time ago).
The whole reason the rev pipe has a separate header section is for ease of removal! The pipe was developed for the MTGP (Mickey Thompson Grand Prix) series of the past and since those guys were always pulling the jugs and doing engine work between races, it was easier to design a pipe that allowed removal of the jug w/o having to pull the entire expansion chamber. It's a convenience thing. Pretty cool, eh?
Next time I have a Pilot specific question, I'll just go straight to Neil and get the info correctly from the start.
