Rb25det Front Facing Plenums

[daxter]

Hi

Just wanting to know if there is anything wrong with changing the stock throttle-body on the Rb25DET plenum to front facing?

My reasons for changing to front facing is too reduce lag and increases throttle response.

Are there many people here who have done this mod and gained good results?

Or am I better to spend the money on a genuine side feed unit RIPS, GReedy ect

(aiming for 240rwkw)

[SLY-25T]

havent done this myself mate but ive seen a bit written on it.

some people have cut there original throttle body off their stock plenum and had it moved to the front. personally, i dont think this is sufficient for flow purposes. the second pic shows this. as the stock plenum isnt flowed etc for a front facing, i dont think the air flow would be even going to all the cylinders. RIPS make an awesome looking front facing plenum

or you could always go for the GREDDY one and im sure there are more out there.

the only thing is that when you put this on, your intercooler piping needs to be changed. must people have cut a hole to do this.

i guess it will increase throttle response etc due to the shorter intercooler piping.

gl

[daxter]

Hi auss13

That RIPS item looks hot, any idea on the price?

Ive also found Boosted Performance who does these -

$700 Installed (Everything supplied, joiners + hoseclamps etc)

I see there is a lot of controversy on changing the stock plenum to front facing, but Ive also seen people who have gone ahead and does this anyway with good results.

I'm sort of leaning towards the Boosted Performance setup tho, drive in drive out, done and good price.

[bombtrack]

2 noob questions:

Where are boosted performance located?

Where can I get RIPS products?

Cheers!

[SLY-25T]

a few people have chopped their stock plenum and had great results. but im just saying from my personal view, i would rather buy one thats made that way.

unsure where boosted is bombtrack.

RIPS is from NZ and he has a profile on here. just do a search for plenums as this topic has been covered before along with prices

[dano4127]

a few people have chopped their stock plenum and had great results. but im just saying from my personal view, i would rather buy one thats made that way.

unsure where boosted is bombtrack.

RIPS is from NZ and he has a profile on here. just do a search for plenums as this topic has been covered before along with prices

What exhaust you running - looks the goods!

[daxter]

bombtrack - boosted performance is also in NZ

[SLY-25T]

thanx mate

its a Fujitsubo Jasma exhaust. but ive done some searchs and cant find it anywhere cause it came with the car. dont think they make em any more.

[**RB2530**]

Cory,

Factory plenums modified to front facing...do they work? BUT read on

I have had this debate with many internet scientists on these forums...IMO The front facing plenums will work but simply do not work as well as ones such as the Greddy one...

It all depens on what you classify as working.

If you classify working as supplying air to each cylinder with enough consistency between cylinders so as not to blow up the engine through lean out, they do work. If you want to achieve the best possible distribution of air between cyclinders to maximise performance, they don't work...

For front facing plenums I would only use the Greddy style plenum or similar with the taper. There is a reason they are tapered the way they are...plus it is no coincidence that this shape also happens to be the same as the RB26 plenum...It has been designed for even flow at resonably high fluid velocites

cheers

[dano4127]

thanx mate

its a Fujitsubo Jasma exhaust. but ive done some searchs and cant find it anywhere cause it came with the car. dont think they make em any more.

nice! is it for sale?

Swap you my Kakimoto JASMA one...

[bombtrack]

Thanks gents.

[SLY-25T]

nice! is it for sale?

Swap you my Kakimoto JASMA one...

lol sorry mate

not for sale. i really like its look. if i could find another one thats shaped this way id sell u mine. lol. but i like it too much

hope u find another one you like

[JET-25L]

This has been covered many times and there's even a tutorial in the tech section on how to do it with a greddy style plenum. A lot of people claim to have no noticeable difference between the stock one. There really is no reason to change the stock side facing plenum until you start making some serious horses (400hp) other than looks and making it easier to work on your car (changing spark plugs etc). There was a reason nissan put it on... even and smooth flow to each cylinder and probably something to do with equal pressure in each of the runners as well.

As for modding the standard one to a forward mount, i would avoid this option as it's been proven that cylinders 5 and 6 can be starved for air with this style.

If you want a really good quality forward facing plenum try one of the following:

Plasmaman

JPC

Greddy

But to answer your original question, no there is nothing wrong with changing to a forward facing plenum. If you want one go for it... Just do it properly and don't skimp on one.

Cheers.

[stricnynel0s]

that pic

http://forums.nicoclub.com/zerothread?id=295315&page=10

and that forum post is about my front facing intake

Edited September 17, 2008 by stricnynel0s

[daxter]

Thanks for all the reply's.

Its interesting to read of people who have modified there stock plenum and swear by it.

Though I'm sure a genuine built front facing plenum is better.

Looking at the SR20DET factory front facing plenum, there very similar to a modified RB plenum. Would be good to pull the two apart and match them up to see what there insides are like.

On another note how much does the length of the runners matter? Factory there quite long, after-mark plenums they look short.

Edited September 17, 2008 by daxter

[R.I.P.S NZ]

www.ripsracing.com in the products section there's pix of a few of our plenims.

There will always be alot of differening information and opinions but if you stick with a plenim that has proven itself to be good in the application your going to use it for thats a safe option.

Most people in the lower hp range usually change for the looks and simplicity of plumbing and maintainence.

We've run 8.7 @ 162mph with just 2 bar of boost in a street car on street tyres and unless we are being REALLY fussy fuel trims between cylinders is not neccessary and when we do trim its only the tinyest amounts.

Rob

[TiTAN]

Thanks for all the reply's.

Its interesting to read of people who have modified there stock plenum and swear by it.

Though I'm sure a genuine built front facing plenum is better.

Looking at the SR20DET factory front facing plenum, there very similar to a modified RB plenum. Would be good to pull the two apart and match them up to see what there insides are like.

On another note how much does the length of the runners matter? Factory there quite long, after-mark plenums they look short.

longer runners tend to be good for low rpm torque.

[PM-R33]

Correct, and the shorter runners like on the greddy one give better top end power but sacrifice low rpm power.

[bubba]

longer runners tend to be good for low rpm torque.

More critical on smaller capacity engines..

My forward facing plenum makings are currently at the fabricators' being cut and welded. GTR plenum onto stock runners with flange for Q45 t/b on the front. Pretty much like the plenum on that 370rwkw RB20..

[juggernaut1]

Thanks for all the reply's.

Its interesting to read of people who have modified there stock plenum and swear by it.

Though I'm sure a genuine built front facing plenum is better.

Looking at the SR20DET factory front facing plenum, there very similar to a modified RB plenum. Would be good to pull the two apart and match them up to see what there insides are like.

On another note how much does the length of the runners matter? Factory there quite long, after-mark plenums they look short.

I have a blacktop SR20 and had the intake manifold flow balanced and extrude honed by Andrew Sanders. The stock intake suffers from unequal flow between the runners and the lower runners are also quite restrictive (Andrew flowed the runners and the plenum separately to gain an undertanding where gains could be made). In the end each runner flowed almost identically and some runners (the poorer flowing runners) picked up nearly 50 cfm of flow at 28 inches. And no the manifold wasn't hogged out to gain that flow increase. The gains primarily came from reducing the audible turbulence occuring in the standard plenum and porting the lower restrictive runners.

Unfortunately I can't attest to the real world hp differences the flow balancing and extrude hone work on the standard manifold would have had as I ended up buying a Hypertune intake.

Edited September 18, 2008 by juggernaut1