Possible big quad throttles?

[Malcolm]

I was at pick-a-part today and was looking at a gen 2 3sge in a carina. I started pulling the intake manifold apart because I'd often wondered if the ACIS thing involved a butterly in each runner, and it does! this bit sits on top of the intake manifold and the butterflies open to increase the intake volume - anyway that doesn't matter, here's some pictures...






they're oval shaped, but if you turn it so you're looking parallel to the open butterflies the holes are perfectly round. I was thinking you might be able to make an adapter plate that goes from this to the inlet ports, and put the flange this part bolts to on the opposite angle so the butterflies are horizontal when fully opened. Obviously you'd have to attach a TPS and a bellcrank, but that wouldn't be a major hassle

the point is though, how big are silvertop and blacktop throttle bodies? The narrow part of the oval on these is 46mm.

[Malcolm]

oh yeah, also you'd have to chop the little plenum off and weld runners on (or make a manifold that will bolt over the top of just the part of this that holds the butterflies, like how the TVIS sandwich goes)
you could possibly just add an inlet to this and make it the plenum instead? It's smaller than most plenums - is this good or bad when trying to make big power?

[RomanV]

I would assume that you would want a much larger plenum than that....

The ACIS 'plenum' is tiny.

Think about it, the volume of the ACIS plenum is the volume difference between the ideal plenum size at low and high RPM for an NA 3SGE.

So I doubt it would be suitable as it is, for a turbo application.

But thats an interesting idea about turning it into quads.
Youd definitely want some long intake runners coming off it though.

P.S. Have a read of this thread.

Blacktop throttles are 45mm inside diameter.