Throttle Location In A Forced Induction

[Twinky]

Hey guys,

 

So my EFI setup is coming along very well and is almost at the state of completion with locking the dizzy being the final step.

My original plan was to supercharge the motor with a light 5 psi setup on the stock 5k. I have been contemplating where to run the vac hose

from the rocker cover and have come to the thought that the location of the throttle body is going to change the way that the supercharger behaves

as well as vac ports. So as it stands the throttle body is nicely sitting on the plenum but I think that I am going to have to move it to the intake of the supercharger.

Would this be the correct way setting it up? Because locating it there will give me a constant vacuum port in-between the throttle and supercharger.

 

In that case what would be a good throttle to use? The EFI setup is using the 4KE manifold so it's quite small. I was thinking of using a throttle body from

the Holden 3.8's as they use the same TPS that I have already set up. Would it be too large or would it be ok to use a slightly larger throttle than the rest of the intake system?

 

Cheers

Edited August 4, 2011 by Twinky

[ke70dave]

how is it done on a 4agze?

 

i would be inclined to just copy that.

[Twinky]

Seems as though all the pics that I have been able to find have the throttle before the supercharger, So I'll do that.

[Hiro Protagonist]

4AGZE has throttle before the 'charger, as do a lot of Roots blower setups - you can have problems with mounting it after the 'charger unless you run a proper bypass/BOV system otherwise since the 'charger is driven by crank speed and not engine load/exhaust gas likea turbo.