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roy-ceffy89
  • roy-ceffy89
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  • Member No.: 179,362
  • Joined: 17-October 09
  • Posts: 177
Post #1 post 6th March 2010 - 04:10 PM


Im looking for some like this but for an rb20.

Anyone know someone who has one?



Are the rb20 and rb25 the same?





http://cgi.ebay.com.au/NISSAN-RB25-INTAKE-...=item3a5865d241


Cheers Guys
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bdup888
Post #2

im pretty sure they are the same.....

TANKI
Post #3

Check on skylines australia, got a gut felling the flange angles are diffrent something like /////\ compared to ////\\

JET_RB25
Post #4

just spend the cash on a plasma man one. Be the best thing you do

bdup888
Post #5

they are around the 2-3x more $$ than anything else on the market....and the only time its worth it is when your chasing 800+hp

roy-ceffy89
Post #6

Yeh i just what to get a cheap one which be good enough for me, Cheers guys.

Half way thur putting the battery in the boot now, its going to be mad.

bdup888
Post #7

just be aware roy that most of the china plenums out there tend to leak coolant

JET_RB25
Post #8

QUOTE (bdup888 @ Mar 8 2010, 09:13 AM) *
just be aware roy that most of the china plenums out there tend to leak coolant



Exactly why you do it once and properly. They cost around 900 which is not that bad as the greddy ones are around 700 if not more and on top of that the china ones as you state suck balls. And they are still 300ish. The plasma man ones promise 20bhp and retain the stock runners so you dont lose any low down torque.

rx2re
Post #9

you cant go past the plazma man one. top quality. As BJ said, do it properly the 1st time.

JET_RB25
Post #10

THat is right. For the posibility of spending 300 and it leaking or not fitting i would save up and buy a good one. Like i said on the phone dude best to just leave it as my intercooler got the air temps on a drift day back to around 28 degrees so around 7 below ambient which is dam effective.

bdup888
Post #11

or you could just modify the stock plenum......same same ph34r.gif

JET_RB25
Post #12

No you cant as the runners are designed to get even distribution from air flow coming in from the centre of the plenum. Nissa would not spend x amount of dollars on designing something when they could have just welded a TB on the front of it to be so much better. Its a cheap option and has and does end up with a blown motor from not enough air getting to number 6 piston.

frcefed
Post #13

not enough air? think you will find its the other way around

JET_RB25
Post #14

nope

JET_RB25
Post #15

with the intake at the from the internal design of the plenum does not evenly disburse the incoming air into the plenum chamber thus starving number 6 from air.

frcefed
Post #16

ok and what damage does that do to your engine?

JET_RB25
Post #17

overloads the chamber with fuel and washes the bore its like running a car way to rich is not good
though i bet knowing you, you wont agree with this anyways but its been proven several times that the plenum mod is not a good idea.

frcefed
Post #18

well first of all you dont know me....
secondly iam not dissagreeing with you that its a bad idea , i was just stating that i think you will find the problem with not distributing the air correctly into the cyclinders will create a lean situation in some cyclinders and begin melting pistons etc etc , you are right that running a engine too rich isnt good but you will have damage from the lean cyclinders a long time before you see a issue caused by being rich

JET_RB25
Post #19

Um yeah i do know you dude. But either way its not a good idea and i will agree to disagree that we both make valid points. Dont do it Roy

Pure-SX
Post #20

do it right the first time smile.gif

JET_RB25
Post #21

STFU you Mr buy built and shit instead of knowing what is in there LMAO

roy-ceffy89
Post #22

LOl cheers guys, I srs didnt know thoses cheaps one would really be that bad. Ive used a lot of ebay stuff and never had any issues with them, i just google the brand name and make sure people have used them before to see the problems if any.

I understand where you guys coming from, but they sell lots of them, maybe 1 in every 5 might be stuff lol. not sure gotta find more info on them.

Cheers for your help. Or this might be cheaper. Where can you get the GTR intake adapter plate from?

JET_RB25
Post #23

Google it dude i searched rb26 plenum onto a rb20 and heaps came up

JET_RB25
Post #24

Some info i found



With all the fabricated parts ready at hand, it took about 5 hours to do the
switch over. It took another 3 hours to baseline and tweak for a good engine idle.

Parts and procedures involved would be..
- 2 adaptor plates being used between the GTR plenum and
the RB20 head. One adaptor plate to match the RB20 ports
and water jackets and another to match that of the GTR's.
- The pipe coming off the thermo-stat would need to be cut,
rotated and then re-welded to rid the interference problem
with the GTR plenum.
- The the cold-start valve of the GTR cannot be at the bottom
side of the GTR plenum because of interference. Look at
the posted picture, it shows that it now sits at the top-rear.
- A vacuum canister has to be made to hold vacuum for the brake
servo.
- The RB20 temperature sender sensor for the meter gauge was
used, this was because the temp reading was way too low
when the RB26 sensor was used, it could be that the sensor
was bad or it is not compatible. I also took no chances and
changed the RB20 temperature sensor (the one that the ECU
reads) too.
- The TPS electrical connector on the GTR is not compatible with
RB20 connector so the RB20 one was used instead.
- Also did some plumbing work mainly for the water and
air/vacuum hoses and also extensions to electrical wires due to
the lack of reach.
- The TPS, Cold-start valve and the AAC valve had to be baselined
and tweaked to attain a stable engine idle. Prior to this the
engine was idling at 2.5krpm and could not be lowered, this is
understandable because the RB26 and RB20 air intake
requirements would be different and hence the call for total
baseline. The 6-throttle positions were also re-balanced.

That's basically about all that was done, I may have missed some
thing but let me know if anyone needs more info.

roy-ceffy89
Post #25

Found this but only for an rb25 lol.
roy-ceffy89
Post #26

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...RK%3AMEWAX%3AIT


Heard really good stuff about theses ones.

HASHIRIYA
Post #27

QUOTE (JET_RB25 @ Mar 8 2010, 03:14 PM) *
No you cant as the runners are designed to get even distribution from air flow coming in from the centre of the plenum. Nissa would not spend x amount of dollars on designing something when they could have just welded a TB on the front of it to be so much better. Its a cheap option and has and does end up with a blown motor from not enough air getting to number 6 piston.

depends what your doing, for forced induction its not really a concern, look at a 26 manifold, all the runners aren't the same length from the opening of the plenum chamber, cly 6 is the furthest from the opening. and it then goes on to how big the plenum volume is.

NA motor would be a different story. and would cause an imbalance.

Pure-SX
Post #28

good on ya bj ya dumb bastard, try to back ya up and what do i get, emooooo tongue.gif

dooche' tongue.gif

I want new movies tongue.gif

roy-ceffy89
Post #29

QUOTE (HASHIRIYA @ Mar 9 2010, 10:06 AM) *
depends what your doing, for forced induction its not really a concern, look at a 26 manifold, all the runners aren't the same length from the opening of the plenum chamber, cly 6 is the furthest from the opening. and it then goes on to how big the plenum volume is.

NA motor would be a different story. and would cause an imbalance.



See i thought the same thing its a pressurised system. So the air is force in. I dont know, ive heard of people stuffing engines and good things about doing a cut and shut.

JET_RB25
Post #30

Well get someone on her to do it and find out dude. See for yourself if it works.

paddles7
Post #31

We've got an ebay greddy copy for an rb25det. Haven't run the engine yet, but everything seemed to bolt up fine during dummy fitment (we heard that was a problem with an older batch of copies). If you're looking at the greddy copy the throttle body opening is 80mm not the stocko 62mm or whatever it is so you need a bigger throttle body or an adaptor. I think it's worth it for the $$ saving over a genuine manifold, and I like the advantage of straight(er) runners over plenums that bolt to stock runners.
I imagine the coolant leak would be between head and manifold? We got ours machined so I can't see it being a problem (I don't know why anyone would buy a cast manifold and not get the faces machined)

frcefed
Post #32

QUOTE (paddles7 @ Mar 9 2010, 08:10 PM) *
We've got an ebay greddy copy for an rb25det. Haven't run the engine yet, but everything seemed to bolt up fine during dummy fitment (we heard that was a problem with an older batch of copies). If you're looking at the greddy copy the throttle body opening is 80mm not the stocko 62mm or whatever it is so you need a bigger throttle body or an adaptor. I think it's worth it for the $$ saving over a genuine manifold, and I like the advantage of straight(er) runners over plenums that bolt to stock runners.
I imagine the coolant leak would be between head and manifold? We got ours machined so I can't see it being a problem (I don't know why anyone would buy a cast manifold and not get the faces machined)


Hope it works for ya , i know first hand of these manifolds as i built a engine for a guy who put one on , the problem wasnt the manifold faces the manifold was actually poures (spelling?) and coolant leaked straight through the metal. this was on a darwin car , screamr. then changed to a genuine greddy and no problem. we never ran the car with the copy so dont know if there is a power or drivability difference between the two.

But hopefully we just got one of the shittie ones and yours is fine

VLCT WALKY
Post #33

bj's on the right track,

the 6th runs lean as all the air goes to the easiest place first being the 6th, hence why a proper built plenum will have vilociety stacks, alot of people think it doens't matter, but u have to ask your self, why do some people engine keep going bang with cheap / home made crap, putting heaps of pressure on the rod and piston through detenation and proper built ones don't have a problem,

with or with out psi it still makes a huge difference and should be put into the machine that measures the air flow under n/a condition and under psi to make sure it flows properly

the RB26 on doesn't count, it has 6 individual throttle bodies, and this does have an effect, but even with the individual throttle bodies number 6 will always run slightly leaner for the reason stated above,

google about plenums from the people that develop them, have a look inside a plenuim that cost's more than $200

it's cheap for a reason, how much is a engine or engine rebuild????

frcefed
Post #34

ah that would mean bj wasnt on the right track . his arguement was rich 6th cycl.

just sayin

VLCT WALKY
Post #35

from the man i brought my plenium off

http://www.skylinesaustralia.com/forums/Co...fo-t210411.html

all the things to take into count

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