Throttle(s) before or after plenum chamber?

[Todd Knighton]

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

	If by "throttle house" you're referring to a throttle body?  There are
many good aftermarket suppliers of misc. diameter throttle bodies to
choose from.	
	If by "throttle house" you're referring to the plenum chamber?  Fab one
your self using some of the formulas from the book I suggested.
> 
> 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 (!).

	The book I quoted was originally published in 1962 and goes into great
detail about the scientific theories behind this stuff.  In other words,
they knew what they were doing, they might have compromised the install
for a car, but they knew it.

> 
> 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?
> 

	Depends on what you have available.  Be aware that rubber tube is
typically not good to use in fuel surroundings as it will degrade.  We
typically fab intake stuff in aluminum, but we also have the facilities
to work with it.

> > 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.

	I put the info on a previous post.

-- 
Todd Knighton
Protomotive Engineering
knighton at net-quest.com