willexoIX

Anyone ever fabbed or seen a set of runners that would go between the upper and middle plenum on a 2.8 MPFI intake?

I was thinking about fabbing a pair maybe an inch or so, depending on hood clearance, to ease the transition of air through the intake manifold.

We all know about the sharp angle that the air has to go through in the 2.8 manifold, and well a smoother transition would make better performance correct?

Thinking about aluminum obviously, but I would like feedback on the optimum length of the custom runners, and how much hood clearance is there in the 2.8 with a stock hood?

Thanks for entertaining the idea, I'm on a budget and can prob fab stuff pretty cheap, being my dad has a machine shop at his job.

willexoIX

Anyone?

58mark

iTrader: (3)

I think it's a.cool idea, but you have to also consider how it would effect the other systems that bolt to the upper plenum, like the throttle body

willexoIX

good point, I'm sure there will be things that need to be adapted, but for now I just want to get a feel for the idea.

When/if I do them, all progress and questions will be covered in this thread.

Post any comments, points or questions as I would like to give this a try.

Maverick H1L

iTrader: (8)

IIRC, if you lengthen the runners, you're going to lose low-end torque, which is something our 60* engines don't have much of anyways. Also, it's not the throttle body you need to worry about but everything that connects to it (throttle/TV/Cruise cable bracket and coolant hoses), and also the EGR transfer pipe from the valve to the intake.

AM91Camaro_RS

I did that at one point. I only did 1/4" thick spacers (plus an extra gasket). I dont think it really did much. There's not a lot of room under the hood to put a very thick spacer in there. You can give it a try though. You shouldn't have any problems with hooking up throttle brackets. i don't think you'll move it enough to cause problems with that. You might have to ditch the top a/c bracket. I did that years ago.

bl85c

iTrader: (2)

No, longer runners produce more torq and suck up top. Throttle spacers and the like are garbage on anything but single planes. If you want to improve your top end make a 'pizza box' manifold. That will cut your runners in 1/2 and add a ton of volume to the plenum.