Plenum Structure

[PortWerks]

I'm designing a custom intake manifold and ran into a dead end. I plan on running individual throttle bodies encased in a plenum to run on a turbocharged application. I understand that the job of ITB's are to push in an equal and maximum amount of air into each cylinder, however how do I know what size to make my plenum to get max. efficiency out of the throttle bodies? I would assume you just need to find the volume of each cylinder and multiply it by 4.. it sounds logical on paper, what do you guys think?

[PortWerks]

alrighty, so I looked a little bit more into it and I guess in most applications, the most efficient plenum size is the volume of all 4 runners multiplied by 2.5 for a plenum enclosed ITB setup, would this mean the volume from the top of the trumpet to the surface of the head? Do I compensate for gasket thickness?

[butch11a]

for turbo itb's i usually go for runner length than volume....for n/a usually 2 to 3 times displacement, depends really on the space available in the engine bay.... here'ssomething i made sometime ago... http://img181.imageshack.us/img181/1056 ... ka6.th.jpg