I've seen a number of posts on ITB's and the pic's are sexier than the avatars!

However, I was wondering if the ITB's are all that they are supposed to be. How would a well constructed plemum with a set of fabricated adjustable length runners with air horns inside the plenum compare to a set of ITB's?

With the plenum set-up there would only be one butterfly in the way so the intake runners would have cleaner flow into the head.

Anyone have any thoughts on this?

John

 

now you're talkin bout fluid dymanics...if you ran as fast as you could, then made a very quick 90 degree turn, how clean could you negotiate that turn? not very. that is why ITB's make decent HP. the path is clear from point A to point B. the thing to watch out for is size for the ITB's. Toda uses 40mm. thats a good size.

 

I agree except that individual runners with air horns in a plenum arent too far off from ITB's in an air filter box. Don't forget that we are dealing with pulsing air rather than a steady stready flow. Additional flow has been found by the placing of a flat plate opposite ITB's so that the reverse pulses bounce back. See 'Pulse Plate' on page 12 of "Engine Management" by Dave Walker.

John