How to Design a Custom Exhaust System

[Ron@Flowmaster]

Originally Posted by Jafa

Agreed, nice write up with some good information.

Question if I may, on the website it gives pipe diameter for approximate horsepower, but that's for v8's. What pipe diameter would you recommend for a 4 cylinder, race-only ( road course ) engine putting out 180hp at the flywheel. 12:1 compression ratio, running straight avgas ( piston aeroplane engine fuel ). Car weighs 2300lbs.

Thanks in advance.

With your horsepower at 180hp, we’d recommend 2.5” mandrel bent tubing. In terms of sound, a Flowmaster Super HP-2 or DBX Series muffler would also be a nice addition to your system. Mandrel bent is key because compression bending will make the 2.5” more like a 2.25” at the bends and disturb exhaust flow. For any other questions or concerns, give us a call at 707-544-4761.