hollywub

Hi All,

The intake plenum on the Kenne Bell 2.6lc is 1000cfm. The Ford Racing twin 62mm throttle body is about 1306cfm.

My idea is to increase the intake plenum CFM to 1300 cfm, by 30%.

I know I can fabricate a new plenum, but I was thinking of making an adapter to add to the current plenum, sort of a large throttle body spacer.

Before doing this, does anyone have any ideas if this will work? I know that when guys make sheetmetal plenums, they increase the body volume of the plenum, not the length.

Would adding 30% more volume with a "spacer" flow well enough?

I don't want to waste the new ported heads and cams with a restrictive intake...

Anyone with applied knowledge to add would be much appreciated.

Diabolical!

Think of the most restrictive single plane point in the intake. That point is going to dictate the max cfm you can flow. Think wider and taller opening, not longer. The reason sheetmetal is popular is because it is thin and strong.

hollywub

Right. Makes sense. That is why the intakes are always a little "fatter" when fabricated, not longer.

I wonder what the inlet on the back of the actual supercharger can flow. Guess I need to take it apart.Kenne Bell is a horrible source for information. They just say 1000 cfm 2.6 and 1800 for Mammoth...

I would hate to go through the trouble of making a new inlet plenum for no gain.

I can tell you this. I went to a full 4" intake tube and ditched the KB plastic oval intake and my AFR went from 11.2 to 11.8.

I think it is a good test to see if the new plenum flows better with the same throttle body and intake tube by watching the AFR lean out or not...

ziperhead

What is a 2.6lc? I am only aware of the 2.6S and 2.6H

hollywub

It's the "liquid cooled". It's probably the 2.6s sc...

Diabolical!

I'd be curious to know how that affected intake temps. It seems that intake temps are the achilles heel of the kenne bell, and squeezing a lot of air through a little space definitely ups the temps. You might have stumbled onto something that will help out the kenne bell guys a LOT.

moosestang

And cheap! You can't exactly bend sheets of aluminum into an intake.


When are you going to get the one for the whipple?

moosestang

I was thinking the same thing about watching the AFR. you could also datalog the MAF or watch it using an aeroforce gauge. it displays the MAF in lbs/min.

hollywub

The 2.8 runs cooler at 15 psi than the 2.6s at 15psi. It could be 2 things. much largero plenum and throtle body or larger sc volume.

I think you are right about it being the small volume of the plenum at the back of the sc creating some heat.

I would also love to build a spacer in between the sc and the lower manifold to do an air to air setup. I have a few inches of room with my hood.

It really does run hot. With 2 heat exchangers and 3 spal fans I run about 70 degrees above ambient temp. Sometimes up to 80 degrees.

I am going to work on the plenum first though.

hollywub

Anyone know what type of sheetmetal is usually used? Is it just 1/8 inch standard sheet metal?
I thought aluminum was used. The mounts to the throttle body and supercharger looked aluminum to me as well...