Inlet Manifolds

[R31Nismoid]

And results that aren't just loaded up dyno ones.

faster lap times, mph, ET... dyno results for this type of thing can be misleading, same as camshafts as they don't really show transient response, throttle etc.

[Rolls]

for the amount of money some of you guys are talking for a manifold, I can make one with custom runners, 80mm billet throttle body and billet rail and all polished....oh and did I mention able to flow more than any of them!!!! similar to the pic below. that is for an rb30, but the concept is the same.

and yes it will accept the IACV

Why does the IACV only go to the first cylinder? How the hell will it idle smoothly like that?

[PM-R33]

God some one take him up on the offer! A free plenum FFS!

[icydude]

To me a custom plenum is not so much about gains but more about function which in turn creates gains.

Evening out the airflow across the cylinders to ensure a happy engine

Removing the rats nest of crap under the plenum

integrating idle control with clever single throttle body setups

going from an rb26 stand point anyways.

[RBceffy25]

Runner length is only really a noticeable thing on NA powered cars where the the length and shape of the runners, speed or slow the airflow through them. In a force induction type of vehicle it has only a mild effect because the air is getting forced into the engine under pressure.

In big power applications well designed runners on turbo charged cars will help with efficiency but lets face it most of us will come no where close to having to worry about it that much.

Hope that helps

I just posted this elsewhere and I feel its worth a mention.

I am pretty sure there were three versions of the intake manifold and heads on the CA18DET all with different runner design. I think most Aussie models have the two runners per cylinder heads and manifolds while I think the poms got the big port single runner CA's. I think there was also a version with three runners per cylinder.

Another example is the 3RZ-FE in my HiLux which has two runners per cylinder.

One runner will be longer and thinner internally to maintain/increase flow velocity, while the other runner will be short and fat for minimal restriction at high RPM.

Take notice of all engines you view and you will be surprised at how long this idea has been in use and how many makes and models use this.

Edit: Also have a look at the manifold on the Toyota 1G-GE/GEU/GTE/GZE, just to mention another.

Edited October 26, 2010 by RBceffy25

[Lithium]

God some one take him up on the offer! A free plenum FFS!

If I was in Oz I'd probably be tempted, I am investigating the bits for the next stage of my build and a plenum would be well needed but my options so far definitely contribute to a large percentage of the costs of "the next stage".

[bubba]

I just posted this elsewhere and I feel its worth a mention.

I am pretty sure there were three versions of the intake manifold and heads on the CA18DET all with different runner design. I think most Aussie models have the two runners per cylinder heads and manifolds while I think the poms got the big port single runner CA's. I think there was also a version with three runners per cylinder.

Another example is the 3RZ-FE in my HiLux which has two runners per cylinder.

One runner will be longer and thinner internally to maintain/increase flow velocity, while the other runner will be short and fat for minimal restriction at high RPM.

Take notice of all engines you view and you will be surprised at how long this idea has been in use and how many makes and models use this.

Edit: Also have a look at the manifold on the Toyota 1G-GE/GEU/GTE/GZE, just to mention another.

Didn't the red top RB20 have dual runners with a butterfly in each secondary runner?

[RBceffy25]

Didn't the red top RB20 have dual runners with a butterfly in each secondary runner?

http://ozdat.com/forum/viewtopic.php?f=27&t=20445

Had another look at the Lux.... I was wrong about that one.....

Edit: http://us1.webpublications.com.au/static/i...7/2740_17mg.jpg

Edited October 27, 2010 by RBceffy25

[bubba]

Ahh butterfly per runner

[ISL33P]

take your pick of these two for the ca18

both surprisingly for a 8 port head, but the one with 4 runners is for a methanol powered drift car which is having the head cnc'd and the 2 ports joined together

Edited October 27, 2010 by ISL33P

[ISL33P]

C'mon, so no one wants a free plenum?

I will help out with the installation and associated pipework.

[migs]

http://www.skylinesaustralia.com/forums/Rb...b2-t342017.html

[DR 32R]

C'mon, so no one wants a free plenum?

I will help out with the installation and associated pipework.

I'm doing a forged engine RB 25 rebuild in South West Sydney, over the next few months. Would you be prepared to test against standard, or Greddy for a discount?

[ISL33P]

against standard would be best....doing against greedy as well would be great

[Lithium]

against standard would be best....doing against greedy as well would be great

Well if you get desparate, I could be convinced though obviously NZ may not be ideal. The bright side is I'd retune to suit as well.

I need to go for a forward facing plenum at some point as I am looking at going to an RB30, though currently I have all stock manifolds.

[DR 32R]

Well, where could things go from here, to a point, I was planning on forward facing any way, my engine builder/mechanic only does forward facing for GT35 forged builds any way. Some of the comparisons are unrealistic on this forum circuit etc, when it's my build and wallet. Both the mechanic and I can get a little tense in the "control freak way". I can forsee dyno only as a comparo. I can only afford one plenum. A Greddy, plazaman would have to be loaned. Stock is on the head. The build would have forged pistons, mild cams and the turbo above. Any result would be qualified by that set up.

[R31Nismoid]

Honestly, dyno doesn't really tell you that much for something like this IMO.

Same as cams.

You can see the graph move either way and what have you, which is fair enough.

But if the car is not actually any faster - then it brings back to the point of "why do it?" in terms of value if you get nothing out of it than a different line on some paper.

[DR 32R]

I guess it's a limitation of all forums, I'm going forward facing any way, even if it's "just for looks", I'm sure there are genuine gains, it's hard to prove a point, that something "feels better" sounds better "seat of the pants etc". Cost to me is time and real dollars. I don't have the time and money for strip and circuit testing etc. I'll stick with my time my dollars, my way.

[ISL33P]

it can tell you horsepower, toruqe and lag differences, what else do you want? This is what everyones wants to know. I know you are stuck on the whole price legality thing, but there are plenty more who think outside that little square.

I also have an egt logging kit to throw in there if need be. Its all about the engine's performance, how that translates into the real world can be affected by many factors, so we will just stick to what can be prove with little doubt and anything else is up to the individual consumer.

[DR 32R]

Victorian modifying seems to be tied to a "high flow" turbo and a FMIC, nothing else visible.