Performance Exhaust Research

[smcohio]

Currently pulling together information, pictures and measurements on performance exhaust systems for the FT500. Any help will be greatly appreciated.

[J6G1Z]

Currently pulling together information, pictures and measurements on performance exhaust systems for the FT500. Any help will be greatly appreciated.

Pull up the search feature. Select all the headings under "First Generation Ascots" along with the "General Technical" underneath the "Round The Campfire" section. Enter "Exhaust" into the search & begin reading the results. That should answer most questions.

J.

[smcohio]

Currently pulling together information, pictures and measurements on performance exhaust systems for the FT500. Any help will be greatly appreciated.

Pull up the search feature. Select all the headings under "First Generation Ascots" along with the "General Technical" underneath the "Round The Campfire" section. Enter "Exhaust" into the search & begin reading the results. That should answer most questions.

J.

Yep I have already collected alot of info from all of this.
How did the thumper stuff exhaust age for you? Still holding together? Anything you would change? Any mistakes besides the collars and some slight bending to get fitment?

[J6G1Z]

Thumper-Stuff header is a nice piece.

I think the primary tubes may be a bit large for a stock engine, but still a better design than the OEM pipe. Slight loss of initial torque with stock engine, but quicker throttle response.

J.

PS. Check this out: http://ascot500.com/index.php?topic=4.0

[smcohio]

Thanks J. I have referenced some stuff off of that drawing. I have made several exhausts over the years and with the very limited options out there I would love to make a great exhaust for the ft500. I have looked into kerker, white brothers, jemco, and some various other one off exhausts that have been made over the years. Looking for all input on all exhaust systems to know the pros and cons of all of them were. Hopefully in the end o can come up with a well rounded exhaust.

[J6G1Z]

I suspect the HRC exhaust design favors a high RPM track bike.

Think I would try for long slender primaries to maintain velocity that merge as seamlessly as possible into the collector. I like the reverse megaphone design. http://victorylibrary.com/brit/mega-c.htm

I'm not much of a BMW fan, but found this interesting: http://bmwmotorcycletech.info/InExTuning.htm

J.

[Dynachuck]

I used 1-1/4" OD stainless tubing for my headpipe,  but installed an integral torque cones in the flanges roughly equal to the stock ID (.875). then at the collector, I went to 1.75 OD, then to a werkes exhaust can. (which has a reverse cone shaped perf tube inside.) I was amazed at the difference to the pipe i had before which was a roached out stock header with a mechanical baffle. Note that i have an open air box and foam Uni filter.  this thing pull hard now. may people think that 1-1/4" head pipe is too big for a stock bike but the torque cones seem to make up for that and it does still have nice top end.
I got all of my material from cone engineering, (180's, straight pipe and collector) but making it this way was a lot more work than i thought.  (every change in direction requires two welds and a pie section) next time I'll use a tubing bender.

[smcohio]

I do agree that the hrc pipe is a little too open of a design for a road pipe that needs to utilize the full rpm range.  As stated in the link that you attached about reverse megaphones they are designed to increase velocity at the exit of the pipe which is a great thing to have at that point. I wish that my father in law was  in this forum because he has a great conversation about the science of a reverse megaphone. If you are ever on advrider i recommend having a conversation with markk53, be prepared because one question will turn into a 3 day conversation haha. As dynachuck was saying about torque cones you need to keep the back pressure and heat contained to a certain point in the pipe to maintain your low end torque range and then after that speed it back up on the exit with a reverse megaphone design. And lastly the final pipe will be mandrel bent so very little weld sections.

[J6G1Z]

...I wish that my father in law was in this forum because he has a great conversation about the science of a reverse megaphone....

Please feel free to invite him over if he has an interest.

Thanks
J.