Outlet Plenum Modification

Rich Thomson

Registered User
I have been going through the IC system identifying the restrictions. If you port the raised top you can get 2.4" ID (more on this later) also the Outlet plenum is 2.4" opening while the intake opening is 3.69" x 1.44" which is 5.31" sq inches or equal to a 2.66" pipe. So I find several limiting areas in the IC system. The top and Outlet plenum opening are my focus here. Extrude Hone would save alot of grinding on the outlet plenum and gain about another 1/16" ID. So without major fabrication 2.4" ID is it for the IC system.

Anyone have ideas or mods they have done that would allow greater flow through the IC plenum.
 
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Rich,

On Chris Wise's intake we tig welded additional aluminum and Chris machined the opening larger and made a custom adaptor to match the volume of his 3" IC tubes. As you can see from the pictures it required lots of fab work and the fit is very tight.

Here are a few pictures.

weldedintake.jpg



topandintake.jpg



sensors.jpg


David
 
gee wizzz

i knew chris was into some heavy duty engine mods but damn i never saw pictures of his work.

any full engine pics, or whats his website



thanks
jim
 
Lots of Work

I see that it requires many hours of fab work. Has Chris flow tested any or all of the system? From the SC top to the intake I would like to see what CFM air flow it is capable of flowing at 28in water. As for selecting pipe sizes I would have thought a 2 3/4" IC system would have been able to support the air flow. I believe the modified M90 is capable of flowing 600cfm do you belive it can flow more? Your thoughts?
 
Rich,

I would have to agree with your assesment about pipe size requirements. The MP FMIC on my car has 2-3/4" ID tubing from the SC top to the IC and from the IC to the intake manifold adaptor it uses 2-5/8" ID tube. My manifold and intake adaptor have both been ported by ESM to flow more than stock, but it isn't nearly as large as the opening on Chris's engine.

Chris is running a little higher compression, 1500 CFM Spearco liquid IC and is stroked to about 4.2 liters, other than that our mods are the same or very similar. He is only making about 15 more rwhp and 20 more rwtq than I am, which is most likely coming from the increased displacment.

So I'm guessing that 2-3/4" IC tubing will flow plenty of air. I think he only used 3" because of the pipe adaptor sizes that came on the IC. I'm sure his will run better in the summer though not because of the pipe sizes, but more because he can cool his intake charge down below outside temps and I can't.

I think Chris used 650 CFM on the Dyno 2000 modeling program. He has an ESM late model and I have a Magnaport II. We are both overdriving the supercharger by about 23%, so I'm not sure how much CFM it's pumping at 6000 rpms.

David
 
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