R33 Intake Plenum

[BookyVL]

StockyMcStock,

I had the entire engine built from ground up in the VL. This was something I asked for so the cooler pipes didnt go back over the engine because as everyone knows, heat rises!!!!

Give them a call mate and ask becuase i could only tell you that I spent $13,000 in total, no break down on the price.

btw, this was about 3 yrs ago now and I have sold the car...unfortunatly..

[ISL33P]

stocky - you can flow test all you like, the dyno doesnt lie (much) when you have back to back comparisons

[neo32]

dude where can u get greddy plenum for $ 900

[paulr33]

I have a cut and shut plenum identical to the one on the VL that i am looking at selling because i can get a greddy for $900 (brand new).

I have been told that the cut and shut is fine as long as you use a standard turbo and dont run more than 1 bar. The problem is that if you exceed that it will starve some of the cylinders.

If you where going to do a cut and shut you should probably cut a wedge out of the plenum starting at the front and increasing towards the back (then weld it up afterwards) so that your plenum tapers of towards the back. Then flow bench it and move the throttle body to the front and by then you could have just dont it properly and bought a greddy plenum (probably for the same amount of money)!!!

<{POST_SNAPBACK}>

so whats the point of getting the plenum changed exactly?

[r33_racer]

i believe it was something to do with the piping restrictions because of the space or lack thereof.

[StockyMcStock]

the only real way to tell if it's leaning out a cylinder or two is to take EGT measurements off each cylinder. simply making more power is not what you're looking for. you want a plenum that will distribute evenly, not just flow more air, which is why i said flow testing is largely useless. all it really shows is that a runner has a larger diameter than another and will allow more air through at a given pressure.

just getting more power out of it is not such a useful indication that you have a better plenum, for instance it may simply be making more power because three of the cylinders are running white hot exhaust runners because of the mixture leanness there.

if i could afford a decent jap-brand plenum i would get it, but cutting up and modding the standard one would be a lot cheaper.

[r33_racer]

well you are welcome to do that. it is your car. People are just offering their opinions and/or experiences to make sure you make the best choice before rushing into it. Cause no one wants to see a fellow member make a hurried decision which may cause damage to their engine.

[ISL33P]

..... and that is why i have an industrial digital thermometer to measure the temps of each exhaust outlet.

so are you saying the runner diameters are different from factory, i would have to totally disagree.

even flow is the best indication of a plenum that will no casue vastly diff egt's.

[33SOM]

I have s subzero plenum on my rb25. Regardless of what people say it does make a difference to power/ response. Also the turbo did spool up quicker (maybe less restriction with my 4 inch intake I just sold it though (I think). Only problem is the FC has fits with it and I miss my cold start warm ups

[Spook's_Skyline]

ive got a custom plenum

no dramas so far

just less piping in better positions

Edited October 4, 2005 by Spooks_Skyline

[r33_racer]

Nice. Looks very custom. I agree with the piping verdict.

I have a greddy plenum on my 33...only reason i got it was for the piping change and the tidying up of the engine bay, more access to often checked or changed things.

Each to their own!

[race_snooze]

I was under the asumption that 1 and 6 will lean out, due to the flow being changed with in the manifold.

[TurboX]

I just like the look of mine

If you wait a few months I may do some testing on our drag RB20 as we have pyros on each cylinder exhaust.

I was thinking of swapping my manifold onto it after first testing the standard one - RB20 though!

[StockyMcStock]

sorry i was referring to porting the inlet runners there, which is what most people do with a custom plenum anyway. how'd you set up the thermometer ISL33P? i'd be interested in doing this myself but you'd need six of the buggers, making it possibly very costly?

33SOM: i'm using a powerFC too, which is another reason i don't want to ditch the factory plenum with the AAC valve. cold starts etc are very useful things to have working well i have found.

[Jordan]

I saw this once, it would make everyone happy.

[BookyVL]

Hey, dont draw on my engine (previous engine)

[BookyVL]

Yeah, i guess it would make everyone happy though..

Not sure about the right angle at the end though...

[The Mafia]

well, someone mention that in physics, bends like that could actually speed up airflow...

anyone thought of this?

[StockyMcStock]

no, it would create a horrible obstruction to flow. air conditioning textbooks are very interesting reading. IIRC one 90 degree bend with radius equal to diameter of the pipe is the same as three metres of straight pipe.

[stR33ter]

I FITTED MODIFIED PLENIM TO MY R33S2

WITH THAT AND FMIC STD BOOST POD FILTER

GOT 256 RWHP AT HYPERDRIVE

NO OTHER MODS