Throttle(s) before or after plenum chamber?

[Egil Kvaleberg]

On Mon, 3 Feb 1997, Todd Knighton wrote:

> Max
> power should go up if you do a good job on smoothing the port areas up.

That makes sense. Assuming that a restriction in form of an open throttle
butterfly causes more havoc in the intake runner - which seams reasonable
given the pulsed air flow. 

I'll simply plug up the holes for existing throttle spindles with exactly
the right length plugs - there is no particular restriction around the 
butterflies. 

Any suggestions for a throttle house in form of a short 3-4" dia tube? Or 
must I make one myself?  

> 	don't forget to add in the port length as well.

That has been accounted for - remember this construction dates from the 
sixties. I have a suspicion the intake runner length was dictated mainly by 
the distance available between the engine and the inside wing (!).

By making a suitable smooth 90+ degree bend, I would be able to extend the
distance from the throttle body to the plenum chamber by, say, 10 inches.

What material would be suitable? I assume the walls should be reasonable 
smooth, so a corrugated tube would be out of the question.

I am thinking in terms of a rubber tube, perhaps finding a suitably formed 
radiator hose. Would the rubber walls dampen the resonance wave too much? 

Other materials? Glass fibre/polyester perhaps?

> The book "Scientific
> Design of Intake and Exhaust" goes into great depth on this subject. 

The title sounds promising :-). I'll most definitely get it.

Egil
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