Jump to content
SAU Community

Recommended Posts

Hi all

I've been vaguely thinking about upgrading my inlet plenum on my rb26/30, and have noticed that 3 or 4 vendors have popped up on ebay recently selling the same or very similar cast alloy inlet plenums for the rb26.

An example is here:

http://cgi.ebay.com.au/EPR-RB26DETT-Intake-Manifold-Plenum-/290513936378?pt=AU_Car_Parts_Accessories&hash=item43a3fadffa

SOme of the listings state straight out they are copied from the greddy one. In addition to having a larger 95mm inlet, they claim to boltup to the factory throttles and have a much larger internal volume.

THe other advantage is, being a matte alloy finish, they don't have the 'cop bait' look about them that some other polished or chromed ones have.

Just wondering if anyone has purchased one of these yet, and had any comments they'd like to share. I'm particularly interested in:

1) ease of fitment - did things more or less line up and seal at critical points where it is supposed to, including machined surfaces and bolt holes

2) any interference - eg does it foul on the clutch m/c like many other upgrade plenums

3) inlet piping - how much of a hassle is it to source an adapter flange

4) performance - did it make any noticeable change in performance (good or bad)?

5) overall assessment - am I better off paying for a hypertune or similar?

There is no market for something like this...

If you want less than say 500rwkw then a standard one is fine, if your getting serious about big top end power there is no reason why you shouldn't be able to afford a genuine Greddy or Hypertune

As above. Couldn't agree more. I can't see how going bigger is going to offer and performance benefit.

Infact I've never seen results to show the GReddy is any better than factory.

The nismo one makes a minor midrange diff, but for the price its really not justified at all.

So what is the key advantage with the hypertune style plenums? Is it the internal trumpets, better shaped runners/plenum, or something else?

I'm going to be retaining the 6-throttle setup, if that makes a difference.

well the nismo and trust plenum both have basically the same principal. they have better air distribution (factory plenum send too much air to cyl 5+6 which causes them to run a bit lean). and they are larger volume. larger volume is basically a benefit to on/off/on throttle response. having a larger volume of air in the plenum before the throttles mean when you crack them open there is plenty of pressure and volume there to fill the head. the better design does increase midrange and response a bit. the nismo one I think is a little better in midrange and the trust one a little better in top end. the hypertune one also seems to be a good design.

as far as the cheap ones go, personally I'd stay away. they are usually so poorly cast it's a joke. all the copy plenums i've seen were ill-fitting and needed plenty of work to fit nicely. for the effort spent you still have an inferior product and it leeches money off the people who spent the R+D to design the thing. the trust ones are not super expensive. nismo ones are a little more so but not too bad used if you can find one.

as far as performance increase don't expect it to do anything magic. i'm running a trust plenum on my 32 with the 2.7 Jun engine and it seems to work fine (with 6 throttle set-up). the car is quite responsive and has great midrange but how much of that is due to the 2.7 and the combo of the cams and 2530s or the tune in the motec or the plenum is anyones guess as the plenum was on it when I bought it.

Fair enough. The issues with quality/fitment are enough to decide this issue from my perspective. There is very limited space to work with around the plenum of a GTR so any issues with fitment will rule out any knockoffs as an option. Also the amount of screwing around required to remove the plenum with the motor in the car means I will be doing it once and doing it right - having to remove it because of leaks or gaskets not sealing etc is not really an option.

It seems as if the genuine greddy ones routinely come up for sale for $900-1000, whereas the hypertune ones are around $2k, so I'll probably go with a greddy one at this stage (together with an r33 clutch m/c).

I have a RB26/30 and can't help to think the larger capacity will be better. The reduced velocity from the larger intake should also aid better cylinder distribution. The gains due to the butterflies being after the Plenum are not the same as other plenums however. The linkages on the 6 throttle OEM have to be lengthened by 10mm or so. There should be enough adjusment available to do so. Not sure about clearance from the brake lines on the master cylinder. For the money, I will eventually give it a try. The Casting on there is much better than the Rb25 ones.

Matt

lol, do it. fatz is pretty drunk most of the time so there's a 50/50 chance he'll give you the genuine greddy one for $150... :) worth the gamble I say.

ps your engine bay will be tight as all hell now. 6 boost taking up all the real-estage on the ex side and trust plenum is bloody huuuge on the inlet side, plus the fact you've got a 30 in there. you will never get a hand down in there again!!!

my thing is tight enough now with just 2530s with the same HKS piping you have and hks manifolds and a trust plenum and it's a standard block jun 2.7.... I had to move my PS res too but it's actually a good thing as it takes it further away from the turbo heat. mines now up near the passenger headlight and radiator support.

Actually I reckon the rb30 block sitting the head, and therefore the plenum, up slightly higher would improve access to the lower plenum bolts, and give more hand-space in the critical area which is between the transfer case and the underside of the plenum.

Or knowing my luck it makes it worse, more than likely its the latter.

ps your engine bay will be tight as all hell now. 6 boost taking up all the real-estage on the ex side and trust plenum is bloody huuuge on the inlet side, plus the fact you've got a 30 in there. you will never get a hand down in there again!!!

my thing is tight enough now with just 2530s with the same HKS piping you have and hks manifolds and a trust plenum and it's a standard block jun 2.7.... I had to move my PS res too but it's actually a good thing as it takes it further away from the turbo heat. mines now up near the passenger headlight and radiator support.

I have to move my PS tank aswell. What did you use for the lines?

Actually I reckon the rb30 block sitting the head, and therefore the plenum, up slightly higher would improve access to the lower plenum bolts, and give more hand-space in the critical area which is between the transfer case and the underside of the plenum.

Or knowing my luck it makes it worse, more than likely its the latter.

Yep ,oil filter is easier to get to aswell.

Matt

as best I can remember it's still using the stock ones. just moved. it;s still about the same distance from the PS pump just different place (now near headlight). I'll have a look. there's only low pres line anyway from res to pump so it's quite easy to change.

  • 2 weeks later...

hmmm.... dosn't look all that much different to my genuine greddy unit.

bugger!

It'll be interesting to see if there are any gains/losses.

I'm so happy your doing all the testing on alot of parts I'm planning to use shortly. I just won't be going 3lt... stroker for meee :thumbsup: and a little (mm maybe alot) of giggle gas.

Cheers

Justin

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I wasn’t able to replicate the sound anymore. It was a one time sound so maybe it was just coincidence but it was like small pebbles being dropped in a coke can.   should I try cleaning the MAF? It could be it’s functioning but dirty? I don’t know.
    • Update 4: Hi all. The car drives again! Haven't driven for long, only to store it in the garage again, but the test drive was successful. The coolant and oil leaks seem to be fixed for now. Temps on the engine were also very good, while moving I never even saw 80C water during the approx. 30 minute drive. Ate up all the coolant in the reservoir though so will have to fill that even more when I go to the car next time. One thing that pisses me off is that the RPM gauge is still f**ked, I even resoldered the board twice and used copper paste on the silly screws that are used as connections. Next time I take it out I'll take apart the board and fit new components, I'll see if I can get a replacement IC for it.  I have an appointment set for 22nd of September for the engine tune to 370hp. Alignment also still needs to be done. My hope is that I can get all the legal stuff over with by the end of this season. Anyone of you have advice regarding intercoolers? Currently there is an APEXI core fitted, one of those weird hybrid ones, 600x270x76. I don't think it's bad but it's not new and now I still have the chance to change it now to legally include it in the paperwork. Only issue is that the only options that would arrive in time are a HKS Type R intercooler or generic Ebay spec intercoolers comparable to a JustJap one. Ideally I'd order a Plazmaman but it takes over a month to receive which would mean making the car legal has to wait until next season. Would love to hear some input on this. Same story for my injectors, the previous owner was a nunce and put ID 1050x on the engine. They work but are obviously not ideal at "normal" power levels. But I don't see a reason to change them unless the tuner says it's necessary. I read online before buying a different exhaust that the top secret style rear diffusers won't fit due to the size of the rear resonators. My buddy and I made it work by slightly "adjusting the shape" of the mounting bracket and making some spacers out of 3d print for the mounting bolts. Fits like a charm. Just putting this here in case someone has this problem. Even the hefty HKS Silent Hi Power rear can fits without hitting anything.
    • Well they got my money but they are not getting my gearbox ! 
    • It's needed for rolling idle up, and I think it is a decider on VCT also.
    • I mean, not really. Link ECU's can absolutely still have errors from the ECU thinking it's getting a sensor it's not expecting. I would imagine the speed at the ECU level in Nistune does absolutely nothing anyway? I assume the ECU does not do any fancy TC stuff with regards to front+rear wheel speed or anything of that like anyway. Someone who uses Nistune may be more fluent in it. 
×
×
  • Create New...