Exhaust Pipe Sizing

Proper exhaust pipe sizing is key. These calculators can help approximate the ideal exhaust pipe size for a given vehicle. For the first calculator; input the displacement, pipe gauge, and the engine speed that the torque/horsepower boost is desired at. Try to size the pipe as close to the outside diameter as possible, choosing one size larger when needed. Remember that this calculator will provide ideal scavenging at the RPM given, thus anything after will suffer. If a low torque peak is chosen, ultimately top end horsepower will be reduced. For a calculator based on power for more "all around" applications, see below.

NOTE: These calculators are good for approximations. The only real way to find out what works for a given situation is to try it out.

For more information on exhaust systems. Read the exhaust scavenging technical article or visit the header sizing calculator.