Jump to content
SAU Community

Recommended Posts

Hi Guys.

So in pursuit of making my RB26 a well even and smooth running engine I've done a lot to it, putting all the best bits on it

I'd like to know some more information on the Nismo and Greddy manifolds.

The question is do they make the engine run smoother and respond better.

The theory is these try to get the airflow to each cylinder as even as possible, especially fixing the 6th lean condition.

Speaking to many tuners about it and a lot are in disagreement, most say with modern ECU's you can adjust the individual injector to ensure a proper A/F mixture so these manifolds won't help.

My theory still is though if one cylinder is getting less airflow, for that power stroke it makes it is making less power and pushing down with less power down the crank, and the engine won't ran as smooth.

So my first question is, while the theory exists, in practice how much of a difference does it make - I don't mind spending the money if it makes some improvement in your guys experience if you've ever done back to back.  I know a lot of SR guys notice improvements when they put aftermarket OEM replacement plenums on but have not heard so much talk with RB26's

Much reading I done mentions that this helps get the twin turbos working more evently, I'm running a single though.


The 2nd question is, Greddy or Nismo, big price difference.  And which ones can or can't be replaced with the engine in, apparently the engine needs to come out for these to be fitted.

The Greddy one i wonder why is a 2 Piece.

I'm also considering, the Hypertune multi TB plenum

Edited by RB335
Link to comment
https://www.sau.com.au/forums/topic/474139-rb26-oem-v-greddy-v-nismo-plenums/
Share on other sites

theres people making 900+hp on a stock plenum. not much point in changing it unless youre chasing four figures plus.
... or want to tidy up the engine bay and make it less of a headache to work on. On the downside, youre changing oem stuff that works just fine and increases possibility of failure

The theory of uneven power strokes making the engine less smooth doesn't really hold water.

And the idea of tuning out lean cylinders only works if you put 6x TCs or 6x O2 sensors on the runners to see the effect otherwise you're "fixing" something with no evidence.

  • Like 1
5 minutes ago, Leroy Peterson said:
16 minutes ago, WantGTR said:
theres people making 900+hp on a stock plenum. not much point in changing it unless youre chasing four figures plus.

... or want to tidy up the engine bay and make it less of a headache to work on. On the downside, youre changing oem stuff that works just fine and increases possibility of failure

nothing fits better than or fits like oem. theres larger plenums take up more room and are harder to work on. not to mention they change the angle or position of the outlet so you need to change cooler piping as well. aftermarket is not always better. and GTSBoy is right.

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

    • You’ll be very upset when you bust that too not to mention the gearing totally sucks. Don’t do it.
    • Is the panel filter one that is oiled? Have you ever cleaned or touched the AFM?
    • So.... the K&N air box thingo was too big, ended up gifting it to a mate, well, by gifting it he actually supplied food and beer at the pub,  which was nice, as it will not sit on a shelf in the garage for the next 10 years I did trim up some of the existing stuff to neaten it all up and gave it some wrinkle paint, unfortunately it currently has a used and abused mish mash of different types of hose clamps, 4 big fat T bolt type (shit), and a few normal clamps of vairing sizes and brands, but..... only until the 6 constant tension black worm clamps that I ordered from EFI solutions turn up next week Currently the current hose clamps are triggering me hard, LOL Is this the final version, probably not, I really want just 2 silicone pieces, a straight bit of silicone from the filter to the MAF is easy and will happen as soon as I head into Just Jap tomorrow, the problematic part is a 30° silicone bend from the MAF to the TB that I can connect the engine breather from the head, I found that there are bulk head fittings for boat bilge pumps that should work, but until I can get a 30° silicone bend the alloy pipe, and the 11ty thousand hose clamps, are there for the foreseeable future 4 hose clamps are golden, 6 are grudgingly acceptable, the 8 currently holding it all together is just taking the piss    I've also ordered 60 more retaining wall blocks for the front yard, I mis-gonculated the height that was required to get above the base of the Photinia's (red robin's) that are the hedge behind the front fence, currently it is 2 blocks high, and about 1/2 a block short, so going 3 blocks high will be above the base of the red robin's, and allow some room for mulch
    • It is the stock air box with the panel filter. Everything else is stock except the exhaust at this point, as I also went back to the cleaned 270cc injectors. I will check the RPM when the IACV is unplugged and report back.
    • As MBS suggested if this is happening when the engine is cold you're going to want to remove the intake air regulator and verify resistance + that the shutter is physically opening and closing. At -20C should be fully open, 20C half open, over 60C fully closed. At 20C should be 70-80 ohms. For AAC valve testing using a Consult cable see if you can raise and lower the idle by commanding more or less AAC duty cycle. Hopefully it's pretty linear as well, shouldn't be like 30% AAC valve is barely idling and 40% is 1500 rpm.
×
×
  • Create New...