Ported Inlet Plenum

JJanney

Registered User
I've seen a few people around on the boards with these. What exactly is ported on the inlet plenum to get them to flow better? I assume where the TB mates up and the exit. Anything in between? (Seems it would be hard to port the the interior regions without cutting it in two and welding.)

If anyone has pics of the ported piece, I would be very grateful.

Thanks,
Jeremy
 
I've done a few, here's some random pics. You can port the inlet to 75-76mm but the outlet really doesn't need porting unless you are porting the inlet on the blower to match. The interior of the plenum can't be ported but acn only smoothed due to limited wall-thickness.

'bird

here's a link to pics of the plenum I did for Vernon...
Vernon's throttle body swap

Here's a pic of an early plenum I modified to fit a late blower (couldn't resist showin' off :)). You can kinda see how the radius is transitioned into the port to make a smooth entry.
late931886.jpg


this is a straight-on view of a plenum ported to 75mm for j57ltr. The first 8 inches is smoothed, with the right tool you could probably get farther.
jg536F6.jpg
 
Last edited:
Thanks a lot Wynne, this helps me out a great deal. Now, you mentioned not porting the outlet unless porting the inlet of the blower. Do you have any pictures of a ported inlet that is say, matched to your ported outlet?

When I was looking at my stock plenum, the TB side was begging for some widening.
 
this is what is done to mine

I ported my stock 92 intake much like those above exept,
my lower blower mount is like this [minor welding needed.]
 

Attachments

  • 6.jpg
    6.jpg
    6.7 KB · Views: 252
Back
Top