R33 Non Turbo Intake Plenum

[assad11]

hey guys, i was just wondering if a rb25det aftermarket intake plenum or even an rb26dett intake plenum will fit the rb25de?

thanks.

[Eug]

rb25 yes.

rb26 adapter plate.

fuel rail might need new one.

done.

[GTS4WD]

Throttle bodies FTW!

As Eug Said.. the only real performance upgrade is the RB26 mani.

Edited December 25, 2007 by GTS4WD

[Hesh]

guys im confused ..ive read that the rb26 manifold on a rb20 was less powerful...and i had surmised from that that adding one to my rb25de would be negligable in terms of gains. But on here you guys say that the rb26 intake plenum is the only performence upgrade.

just so im clear which direction to take ..is this for the rb25de? and if so the power and torque gains im assumin are from better breathing and the larger volumes inthe rb26 plenum? Ive heard a brief mention of having the internals of the stock plenum on the rb25 reworked for better gas flow ...anyone done this?

also im confused as regards the routing of the air intake to the rb26....the greddy style ones ive seen withthe throttle body at the front are great from intercoolers but (as i now know ) i dont want one of them ...

so if i want to modify the intake side of an rb25de (after port polish and coby d12 are all done) whats the best way top go about it?

[GTS4WD]

..ive read that the rb26 manifold on a rb20 was less powerful...and i had surmised from that that adding one to my rb25de would be negligable in terms of gains. But on here you guys say that the rb26 intake plenum is the only performence upgrade.

just so im clear which direction to take ..is this for the rb25de? and if so the power and torque gains im assumin are from better breathing and the larger volumes inthe rb26 plenum? Ive heard a brief mention of having the internals of the stock plenum on the rb25 reworked for better gas flow ...anyone done this?

also im confused as regards the routing of the air intake to the rb26....the greddy style ones ive seen withthe throttle body at the front are great from intercoolers but (as i now know ) i dont want one of them ...

so if i want to modify the intake side of an rb25de (after port polish and coby d12 are all done) whats the best way top go about it?

Its not worth adding a 26 plenum on a 20 because the 20 had smaller head ports that all the other RB's.. so the entra flow the 26 offers will be "overwhelming" the 20 head.

In terms of 26 plenum on a 25 head. Yes.. very good idea.. a 26 plenum (correct me if I am wrong).. but it has twin throttle bodies.. better flowing for air.. and a larger amount of air an be taken in through the 26 plenum. You can attach a 26 plenum on a 25 head via use of an adaptor plate. This is your best bet.. Plenums can be quite cheap (factor in exchange rate and your cheering).. Adaptor plates.. I do not know.. The Greddy plenums and 26 plenums are quite similar in design.. but a massive difference in price. Bear in mind by putting on a front facing plenum you will most likely need to relocate the battery to the rear and run a pod in the corner.. or.. if possible.. run piping down into the engine bay itself.. infront of the radiator.. (YAY HOT AIR! )

In a perfect world (where money or mod parts grew on trees) you would want to get individual throttle bodies.. virtually no flow or starvation to cylinder problems..

You will be wanting to modify your stock plenum.. or get an aftermarket or 26 alturnative as its quite hjard to reach a decent NA power figure on a stock intake manifold.. especially if you have had your port/polish done.. you will definately want to be taking full advantage of that too!

Hope it helps Hesh

[unarmed_skyline]

the rb26 plenum has indiviudual throttle bodies not only 2, unlike the greddy which only has one, they both face the fron but in 33's the battery is already in the boot although it is quite a tight fit for a pod to fit on the drivers side of the engine bay, ideally the best way to do it would be run the individual throttle bodies of the 26 plenum and then run individual intake tubes with a trumpet on each ran on to pf where coil paks are and run an ecu which runs map sensor ie microtech so you can get rid of the afm, if anyone has seen it there is an rb30de with rb26head which was built in japan which had picturs floating round, this set-up was done that way and along side with a port and polish some cams and cam gears with some upgraded valve spring is probably the best na rb25 intake/head set-up you'll be able to make.

OHHH i can just imadgine the sound and the throttle responce, do it and post us the vid

[Eug]

jarrod is on the money.

the advantage of an rb26 head is the individual throttle bodies. take off the forward facing plenum and put on some adjustable trumpets.

i agree; big lumpy cams and the butterflies open running at full song would give anyone the shivers.

[unarmed_skyline]

yum yum yum, drool

enjoy, now this is how a na manifold should look

[GTS4WD]

yum yum yum, drool

enjoy, now this is how a na manifold should look

Im willing to sell my kidney..

how much is this going to set me back!?

[Hesh]

wow how much info! cheers all

so those pics are of a set of rb26 throttle bodies with trumpets? would that be withthe rb 26 fuel rail?

i think the way im going to go is to have an rb26plenum, and run the three twin thottle bodies. change the ecu to one with a map sensor and adjust the air intake. I do want to keep the rb25 fuel rail ..just to keep cost down, plus i can then use the standard type injector (without impedence worries) i curently have a K&N panel filter inthe standard air box. from what you say this will have to go.

I have a spec one so the battery is inthe boot ...but if poss i want to keepthe air filter on the passenger side of the car.

(some moddified hard pipe runing where intercooler does on some cars.

the rb26 plenum...three double throttle bodies between the plenum and the head ..AND one at the front> why?

also which ecu's run map sensors ...? will this have to be a standalone or can i get away with a reflash and piggy back.

cheers all and hope you had a good christmas.

[MBS206]

When tuning with individual throttle bodies. To get a nice smooth response, when running a map sensor, you want to look at something like a MAP crossed with a TPS setup.

Reason for it is you can get the same map reading at different TB openings at the same RPM... Yet one lets in more air.

Unsure if it's an issue on N/A engines, but it is a hiccup with FI, and I know the quad throttles on the toyota 20Valve I think it is, have this issue.

The AFM doesn't have this issue.

[Hesh]

cheers mbs206...so you would advocate keeping the afm?

apologies guys for the "slight" highjack of this thread. im trying to stay on topic, but as ive said before this is the sort of stuff that just gets blank looks over here. (swiftly folowed by the line...."bung a turbo on mate....")

this fabled adaptor...does anyone have apicture of a bare one? where can i source one from ?

Edited December 28, 2007 by Hesh

[GTS4WD]

bung a turbo on mate...."

[MBS206]

cheers mbs206...so you would advocate keeping the afm?

apologies guys for the "slight" highjack of this thread. im trying to stay on topic, but as ive said before this is the sort of stuff that just gets blank looks over here. (swiftly folowed by the line...."bung a turbo on mate....")

this fabled adaptor...does anyone have apicture of a bare one? where can i source one from ?

I'd say Yes, And no to keeping the AFM.

Look at things like sound, nothing beats straight off the side of the motor.

Look at extra piping. That's a restriction, minor, but still a restriction.

Then you've got 6 filters vs 1 filter.

Basically, you have to look at how much you're prepared to spend.

I know of only one ECU (Although, I bet there are more) that do a map crossed with a tps tune for multi throttle bodies. And the ecu I know of, is at pretty cheap price too.

But, then you'll need a full tune.

And then, what gains will you get from the 6 throttles + full tune?

Might as well pull the the head at the same time, port it, cams in, etc.

But then, big expense, not a "huge" gain. Are you planning on going turbo later on?

[Hesh]

welll.. i started out just being bloody minded ..."everyone has a turbo so im not" and also my driving routines dont lend them selves to turbos. havng discovered that over here there is alack of knowledge on the NA i thought id do things in stages and amass my own database for comparrison.

BUT

i cant deny that eventually forced induction would be fun .....thought it would likely be a supercharged variety..just to be bloody minded again.......but thats along way off and once shes all sorted i had also thought of an engine transplant (rb26dett) so i can keepthe nice tuned na as is.

(maybe put it in a r32 ..lighter equals more fun!

So im going to do allthe modds like the d12s etc and keep and eye othe fact that i may need better breathing for a supercharger in the future. ...and looooong way inthe future. (like when the daughter is through uni and my pension matures!

the heads already ported/polished. like i say this is a stages thing..ill dyno it at each stage before moving on. so in the medium term im gonna see about getting the standard plenum reworked and a bigger throttle body.

at that point she will have

port/polish

spitfires

coby d12 2.5 and some sytem or other

K & N panel filter standard airbox

xf throttle body and internally wrked standard rb25 plenum.

ecu of some sort.

the main concern is buying a "future proof ecu" so i dont loose money having to upgrade that.....as i know where im going (eventually) i want to keep some parts....ie ecu constant....sothe results in terms of power and torque are fromthe parts/mods im testing not the "new "ecu.

[Hesh]

and gts4wd ...you should hear it mate..they wreally dont want to know unless its got the worlds biggest turbine strapping intothe manifold.......

bloody anoying ...

i posted up over here in england (this is true) a thread on rb25de mods......

1st andswer?

"sell it and buy a gtsT"

oh how inCREDIBly helpful.......its better now though as the guys know im serious.

Edited January 10, 2008 by Hesh

[Hesh]

so has anyone got pictures or info onthis adaptor to alow rb26 plenum etc... to fit ontothe rb25 stud pattern?

Edited January 10, 2008 by Hesh

[maike]

Is it possible to fit a r34 turbo throttle body onto the non-turbo engine? Reason for asking is because I find all the hose from the Non-turbo throttle messy and it would make it easier to get to the coil cover if it was set-up like the r33 throttle body.