intake length with Eaton charger

[striker]

Hey all,

I'm in the design proces of an Eaton set-up (intercooled water-air)

Do the same rules apply to manifold design as in an NA set-up? ie moving the peak power around the RMP range?

Seems that teh richwood manifolds don't have runners at all, someone with some theory behind this?

regards Thomas

 

[Anaema]

doesnt really need any intake runner length, on account of the style of SC. the roots will give instant torque, so it doesnt need long runners. but i do recall seeing very short runners, maybe 1" or so.

 

[striker]

Is that thought comming from the ,in my eyes, misconception that
"boost fixes flow"
or are the intake dynamics actually rendered usless with the introduction of linear boost from moment 0?

I see a lot of different styles of eaton manifolds in the ford dohcV8 corner, some with intakes just as long as the original manifolds.... why would they bother if it doesn't matter that much... there must be something to back both types up.

grtz Thomas

 

[Anaema]

the runner length and such still apply, but its just less relevant when you have a roots blower, as they naturally make gobs of torque from very low RPMs. also, there is just no room under a Lexus hood to put a long runner roots manifold, so a short one is needed.

 

[Zuffen]

The Richwood manifold can't have long runners or it wouldn't fit under the bonnet (hood) of an SC400.

The Ford Lightning also has very short runners.

I think fitting the blower in the valley of a V8 precludes runners of any length.

 

[turboandrew]

If you can get the blower to blow up, in to a plenum, then have the runners go from the sides of the plenum, straight down to the heads, that would give you decent length runners, while retaining the blower close to the "V". This is probably very hard to do with pre '98 motors, as the intake port angle is not upward enough. It is very easy to do on the later engines, and that's what the TRD 2UZ supercharger (also an Eaton) does. Hood clearance still needs to be considered because of the plenum on top of the blower, but IMO, it can be done. The TRD charger will probably not clear the Lexus models' hoods, but that's because they also route the intake path from the throttle (front of engine) to the inlet of the chager (rear) over the plenum, taking up even more space. If you route that on the side, like most chargers, clearance should be a little easier.

 

[striker]

So Same rules apply as per NA engine though the goal of the Low rpm torque will be met anyway because of the blower pushing air in, making "velocity ram effect"(intake veocity vs cylinder filling) rendered more or less useless.

OK cool, I'll see what the shortest runner possible on this engine and it's peak RPM is and go from there. if that fits Yippie if not......

Take a look to jordy's skiboat manifold btw (the M90 one, so before the JAG system) he's got: runners, trumpets and all inside there. though he's got no bonnet to close.

grtz Thomas