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Thanks, Mongo. Our intake manifold project is still very much alive, but as you can imagine the fire we had in the shop set us back a few months. More news on that manifold coming.
I have a 5.3L GM block in my garage and a T76 turbo sitting next to it. Trying to avoid the temptation of putting that in with a *GULP* Renegade Hybrid kit.
We had a shop fire last year, and that set everything back a bit. This project is still very much alive, and has floated to the surface of the list of product development again.
Let me get past our 20th Anniversary Open House on 9/28, and then I will be going on this project again.
When I left off, I almost had the flanges done to my liking, they have one more tour through the machinist and I to go. It will go faster after that.
Just to return the reader to the original track... our current intake manifold development project is to take this manifold (picture below) which proved out very well on the engine dyno and repackage it so that it will fit completely under the hood of a 928.
My goal is that the new manifold fit without any modifications to the motor.
To get the plenum to fit under the hood isn't that hard in this case. With the manifold pictured above, we only peaked out of the hood about an inch at the front, and we were beneath the hood at the back. The customer that commissioned that intake manifold wanted big numbers and didn't mind if the HP curve was peaky - hence all the runners the same length.
But for road racing or street driving, you will want a intake manifold that does not produce peaky output curves. Usually a road car prefers a nice broad power band. So I plan to simply shorten the runner lengths at the front a small amount, not unlike the manifold I made below, and this will not only allow it to fit under the hood but it will also broaden the power band nicely.
The intake manifold in this picture makes some 700+ HP NA (estimated) and 1114 HP with 20 pounds of boost on our 6.5L 928 motor. It obviously flows extremely well, and fits under the hood of a 928. The problem with it was it was very expensive to make, and the heads and the water bridge had to be modified to accept it. The plan for the new intake manifold is to flow similar numbers, cost much less to manufacture, and not require any special mods to any other part of the engine. The new intake will have one plenum, instead of the twin plenums shown here.
I hope you can see from these pictures that the difference in height from the back of the plenum to the front isn't that great. That's all I needed to get it to fit under the hood of my 928.
03-06-2019, 10:48 AM
