Intake Plenums, does size matter

[BrianRA23]

That TRD manifold just show how much of a restriction they have had to apply to stop all the air rushing to the end and making cylinder four leaner than the rest.

If the air is considered a liquid then this becomes more apparent. With a hose blocked off at the end and a set of hole in it the result is more water out the furtherest one. This was shown on one of the early stages of the Zoom mag Excel project car, before it was supercharged.

Initially they found that there was a vacumn at full throttle and were going to fit a larger throttle, but decided fitting a second throttle to the other end of the plenum would provide a constant flow across all cylinders. Maybe if they had tried the larger throttle first it might have been able to truly verify the point, but I was convinced.

For the turbo engine it seems leave the runners alone (or make them the same size as the ports) with length being relatively unimportant, then position the throttle and design the plenum for even, unrestricted flow out of each runner.

Equal amounts of fuel, equal amounts of air to all cylinders makes the engine more tunable, other wise you might just be tuning to the average. If one cyliner is not providing its fair share of power and its rich or lean exhaust gases are being used to add or remove extra fuel to other cylinders the whole engine has to suffer. Any tuning done would then be a compromise.

[cptsideways]

I've always wondered why we don't use a reversed exhaust collector style, It would seem to make sense. I see how the intake trumpet itself need a full view of the incoming air as such otherwise otherwise one or another may get a preference.

If liquids are anything to go a smooth intake route is far more important than volume.

[BigWorm]

I've always wondered why we don't use a reversed exhaust collector style, It would seem to make sense.

You mean something like this?

[Ben Wilson]

I've always wondered why we don't use a reversed exhaust collector style, It would seem to make sense. I see how the intake trumpet itself need a full view of the incoming air as such otherwise otherwise one or another may get a preference.

If liquids are anything to go a smooth intake route is far more important than volume.

The problem with a reversed collector style manifold, is it's very difficult to do with short runners. I think the Echo motor might have something similar factory.

[ReQuieM]

I sketched up an idea just like that on sunday night. tho i have got a design that suits a turbo 4 cylinder/twin turbo V8. I think for a 6 it would be a massive pain. You need to go 1-2-3 splits to get truly even flow.

[SLO-055]

doesn't the 3S previously mentioned run in JGTC??? if so it'd have a restrictor on the inlet somewhere, maybe the plenum is designed around that...

[BrianRA23]

I sketched up an idea just like that on sunday night. tho i have got a design that suits a turbo 4 cylinder/twin turbo V8. I think for a 6 it would be a massive pain. You need to go 1-2-3 splits to get truly even flow.

On one version of the 1JZGE they use the 1-2-3 splits as you suggest and where it splits into two they are at least 20cm long with quite reasonable cross sectional area. The butterfly sits between cylinders 3 and 4 but over above the exhaust side to get maximum length.

[ed]

the 1uz's plenum...

note - the intake pipes are just kinda clamped on to get an idea of position - they wont actually protrude that deep into the plenum *der*

volume is 6.5L per bank

[JustCallMeOrlando]

That is t3h s3x. I love it.

[takai]

Looking good there Ed, bridged over in the middle to increase plenum size i guess. What are you runners going to look like?

[ed]

runners will just have short 30mm tall bellmouths (90mm dia flare) on top

the x-over:

basically a balancer rather than a volumer expander. will help cancel any resonance that may decide to try and establish itself in either plenum bank.

its also a convenient way to encapsulate the linkage arms insie the plenum making it a sealed system

[takai]

Ah ok, i was wondering whether you were going to use the larger plenum size to extend the length of the runners. Vaguely in a cross over design.
I had a brilliant pic a while ago of the induction system on one of the V8 Supertaxis, but i cant find it now

EDIT: Very much like this

But carbon and better spacing.

[ReQuieM]

Ed: they're skyline throttle plates yeah? Any chance I could get a copy of the flange set up on them? I'm using a set for my 1jz some where down the track...

What format do you have them in? Im not that familiar with CAD (the missus is) but can it be exported into another format? Like a vector eps?

Did you use CAD to calculate the volume? My GF can use CAD basicaly but she doesn't have a clue with 3d so i can use it to work out the volume of my intake set up! Any hints, tips ect? OR this is a big ask i know, but if I provided 2d vedtor art could you 3d it in CAD? Yep i realise it'd take more then a place file ect, Let me know man!

Last Q, any pics of how your seting up the linkages to the throttle cable? thats the part I have SFA info about and have no idea how to tackle just yet.

Thanx

Sorry to get off thread!

[ReQuieM]

PS love the $20 bunnings work bench! I've got one too, killed it in about 5 secs when doing my IC piping tho!

[ed]

Ed: they're skyline throttle plates yeah? Any chance I could get a copy of the flange set up on them? I'm using a set for my 1jz some where down the track...

What format do you have them in? Im not that familiar with CAD (the missus is) but can it be exported into another format? Like a vector eps?

mate, i just saw this post - sorry...

yeah, very very esy to get you the CAD files for the rb26 throttles...

i can get it to you in .dxf formate which should be cross compatible with practically any CAD program...

fire me an email: [email protected]

cheers
ed