Is there a formula for calculating the size of a plenum chamber, I'm thinking of making one for the jaguar, in case the ITBs don't work out. It will be along the lines of production car designs with the 6 runners into the plenum, and a single throttle body on to and air filter.

I have googled, and found lots of references to small plenum good low end / acceleration, large plenum good top end but poor acceleration, but nothing for a good all round chamber.

If all else fails I'll fill an XJ6 plenum I have with water and see what its volume is, but I'd like to be a little more scientific

Cheers.

Pete.

Bell suggests 0.8-1.5x displacement on 3-6 cyl engines.

Given that the primary purpose of the plenum is to ensure even air delivery at the required pressure to each runner, I would work on the basis of aiming for the 1.5 and making sure it is designed well.

[Edited on 11/6/14 by coyoteboy]