In your own opinion, which of the three in our TPI system is most restrictive for performance and what would you do to improve it? The phlenum, runners or intake manifold? Go nuts guys. I think it's the phlenum and runners. A larger phlenum would draw and hold more air and larger runners would be able to deliver it to the manifold.

 

In order of restriction..........

1. Base manifold

2. Runners

3. Plenum

Actually, I don't consider the plenum a "restriction". It's shape and design is a function of the TPI systems long runners.

 

Just like Acceld says!

 

Would it be fair to say then if one was to purchase shorter runners with a stock phlenum, the gains would not be as noticable if the shorter runners were used with an aftermarket phlenum?

 

Ive never seen an aftermarket plenum in the same tpi style as stock... But what your talking about is pretty much the super ram. shortened runners and a big plenum.
After porting runner and plenum and evaluating the base on the car I can see why everyone says its the most restrictive. Not much you can do with stock runners other than clean up that lip where the tubes meet the flange. I dont think a stock plenum is terribly restrictive or anything but porting it is easy and makes a pretty decent difference at WOT IMO. You would be surprise how poorly made the 2 holes for the TB were made... I also cleaned up the bolt nibs that enter the plenum to make them a bit more aero dynamic, doubt it make a difference but I figured it cant hurt.