Exhaust discussion?

[special-k]

Since l finally put my flattracker together it' kind of lit under a fire under my ass lol A Anyhow is there a general rule of thumb for type of exhaust system? We race in vintage 1/2 mile flattrack. At the last race we had 4 yamahas and 4 separate types of pipes lol

 

[MaxPete]

Interesting....what sort of pipes and where do you race?

 

[special-k]

I'm in southern ontario. I have 1 5/8 primaries going into a 3"x14" collector with a 6" perforated tube baffle 1 3/4 id with a stock 256 engine and 36 mikunis. The other guys had a 2-1 with longer primaries dumping into a single 36"? Jemco style megaphone. That was a full race 750. The third one had off the shelf jemco high pipes with a mild 256 style 750 and 34 mikunis. The final yamaha has a mild 447 style 750 with dual short megaphones down low. Phil Little style. Looking forward to different theories.

 

[Signal]

My advice is buy the 650/750 Engine modification guide. Its a PDF download from 650 Central.
Lots of info on pipes that have been used for racing.

 

[grizld1]

+1, Signal! Craig Weeks is the author, and he's a member here: board name 650performance. Craig did a wonderful job of research, backed up by his experience on the track and on the bench.

 

[DanielBlack]

I couldn't find the download on 650Central. But I did find it at 650performance.com

 

[grizld1]

Right, Daniel, you can't order the manual from 650 Central, but there's reference to it with a link to www.650performance.com on the 650 Central home page. I should have posted the link before, sorry 'bout that.

Guys, even if you're not interested in doing performance mods to your own motor, Craig's manual is a great read. If you are doing a performance engine build, the manual will save you many times its price in bullets dodged.