So I'm looking for advise for a 13bpp exhaust set up. Track day car only with no sound restrictions at the tracks I frequent. I have about 72" to work with, any ideas about primary lengths, when to add the collector etc ... thanks in advance

Scott.

 

we really only know 2 things,

first, it helps to have a straight section from the engine. the RB headers are like mid bend from the engine, and if you start measuring its weird. straight is better.

two for lengths, longer tends to have a broader power band, and short tends to make more top end. how much, will depend on other stuff, so you'll just need to cut and paste.

for my car i (someday) will buy three 4' sections of pipe. one of these gets cut in half. so have two 4 foot long pipes, 2, 24" pipes, the header, and collector. with some clamps, i can then just try whatever the header is. add 2 feet, then try 4 feet, and then 6 feet.

so its like 4 dyno runs to see what mine wants.

 

Great thanks!! what about i.d. of tubing? not a lot of info out there on the internet, seems to be some kind of black magic!

Thanks Scott

 

Rotary Tech Tips: Exhaust System Configurations

Towards the bottom of the page there is a table that lays out guidelines for building exhaust systems for different kinds of engine porting

 

Get in touch with Carlos at CLR motorsports out of Miami. He has done a lot of dyno testing on different configurations over the years and may be able to help depending on your configuration.