Jump to content
SAU Community

Recommended Posts

So I've noticed on eBay there's a few greddy 6 throttle body's intake plenum replicas on ebay, now the greddy is around the $1100 mark and the eBay jobs are around $300 to $500 but still boast of decent power gains. Has anyone brought a eBay special and noticed the gains with there rb26? Or had any troubles with them?Or is it best to stay with the original intake?

Link to comment
https://www.sau.com.au/forums/topic/444211-ebay-plenum-for-rb26/
Share on other sites

Who's to say the Ebay one won't also?

Have you checked this theory by measuring the egt's in each runner, or are you just happy to quote old wives tales? Gibson didn't have any trouble with it afaik...

I'm just asking questions to find out if it's worth while or not. I'm no mechanic and trying to find these things out on google is hard if not to no answer at all. That's why I've tyres to the forum to hopefully find someone that has done this and that may help me out

People do all kinds of stupid things, that doesn't mean you should copy them... :P

I have seen 500kw through a factory setup, intercooler, plenum, manifolds, piping, airbox, fuel lines etc. If you are near that I would be more worried about the block splitting than the runner flow. Just run a fat mixture and cram some more boost in.

Just to help the OP, ive got a genuine Greddy and had a ebay/china copy side by side.

You had to look really hard to spot the differences, runners, diameters, everything identical, slight differences in casting lines...very slight.

Would come down to the quality of the alloy IMHO.

Ive met and spoken with a Chinese manufacturer that makes them, as he said to me with any part, supply me with the brand name original and ill copy it for a fraction of the price and you wont tell the difference.

And just to throw a spanner into the works, he was offering them to me for $US 80 dollars each 2-3 years ago, no wonder there are so many copies out there......

Would come down to the quality of the alloy IMHO.

This... And how it's actually made. You can have the same materials, same design (making a mould isn't hard) and still stuff it up by having the casting temperatures or cooling speed all wrong. End up with a brittle part of the product which will be the first to crack under a high load.

Personally, I wouldn't want anything potentially breaking off a scraggy bit of metal under high temp / pressure and going straight into my engine. So if you go for a cheap copy get it checked out with a scope and cleaned up before it goes near the car.

  • Like 1

I found a few forums searches off google saying that they lean number 6 , thought I'd ask before I finished my motor because it would be easier to change a manifold whilst it's out. I'm thinking I might buy the greddy/trust manifold for peice of mind

Re cylinder 6 - true. Although tuned around.

Stock plenum is awesome and you will have no issues so keep it. Don't waste your money on these for the RB26

In my opinion the best is the Nismo Plenum - max 2-4% improvement - EDITED: 1-2% power and 0.4% fuel saving - SUBJECTIVE. Yes I have one

At $1500-$2000 money is spent better elsewhere.

Topic covered heaps already

Edited by Sinista32
  • Like 1

I'm building my motor ATM to have around 450 to 500kw

I found a few forums searches off google saying that they lean number 6 , thought I'd ask before I finished my motor because it would be easier to change a manifold whilst it's out. I'm thinking I might buy the greddy/trust manifold for peice of mind

I see.

Well I'd double check with Racepace, just give them a call to confirm.

As I have said before, you can get decent power gains with the stock Inlet Plenum but how much to what point, I'd double check.

So yeah, don't go throwing your money on ebay parts.

I noticed your user name and that you had a R32 GTR, so im assuming your doing a RB30 bottom end?

If so, before you go any further, the Greddy plenum will hit your clutch master, there are work arounds, or a few ways to do it but if your only going to 500Kw you may as well stay with the factory item, it does still work well.

Yes 6 can lean out, or run leaner, quick cheap way is get your injectors flow tested and put the highest flowing one on number 6. ;)

Otherwise 6 EGT probes on the manifold will do the trick......as will getting the tuner to run injector 6 a little longer.

Edited by GTRPSI
  • Like 1

Yeah mate I'm halfway through building a 26/30. Can the stock manifold be port match to the head or is it already done from factory? Also is there threads on how to fix the greddy manifold with the clutch master cylinder touching?

There are a few threads, all with different suggestions/methods in the RB30 section.

From using spacers under the cross member to steering shaft spacers to cutting the bonnet, some even remove the clutch booster and use a different clutch slave with spacer.

We are doing the same build right now for our 26/30 R32 GTR.

Edit, Forgot to add, port matching always helps, all depends on how far you are going or are prepared to look at details.

Edited by GTRPSI
  • Like 1

I've had the 30 bottom end in my GTR before but I never went crazy on the head. My n1 pump let go so I'm spending abit more this time. But all I did was cut the inner braces out of the bonnet and tapped the floor up abit with a hammer near the low mount dumps for clearance. Everything else was sweet. Well I've got an aluminium die grinder bit so I better port match it

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

    • Does that German restaurant still exist in the old place out the NW end of Goulburn? When I say "out the NW end of"...I am really being vague. It was 1997 when I was last there, and the only point of reference I can recall is that it was on the opposite side of the main drag from the big merino. And when I say "opposite side of the main drag", I don't mean "on the main drag". It was either a couple of streets back from there, or might have even been out in the sticks a bit further. Was an old farm building or mill or somesuch. And when I say "the big merino" I might actually be thinking of a completely different part of town, because I just looked on maps and the big bugger is not where I remembered him to be! The food was good, consisting largely of various German mystery-meat sausage/loaf things and kartofflen.
    • So while the second sentence is completely correct and the whole point of the conversation, the first sentence bears consideration. If this bloke is just hoping to throw big turbos on and drive it around, because there are no helpful facilities at all in his tropical paradise** then he likely has zero chance of even knowing what the TP is on the last column in the stock maps, let alone know whether the ECU is operating anywhere near it or past it. So the point is very very moot. And, per what I said before, at stock boost on those turbos, you may well be off the end of the map. **I'm just back from Vanuatu, so I know exactly what small Pacific nations can be like wrt paradise without requisite facilities. But it's not even that simple. I put a high flow on my car and had to drive it around with a proper tune because of the lack of opportunity*** to put the bigger AFM and injectors into it to allow it to be tuned. I had to turn the boost down to less than I had before, and back off the boost controller's ramp, because it was exploring parts of the map that it didn't drive in before, and really couldn't access for tuning on the dyno either, and so was pinging. It was still well within the last column, because when I first**** set up the Nistune on the Neo I rescaled all axes of the maps to give some more space to explore. ***Family dyno was broken ****This was 13 years ago, and the TIM thing wasn't a thing then and so TP would definitely grow when pushing past the stock tune's limits.
    • Yep, this bit another local owner. I caught it before putting the transmission back into the car, what I noticed was the pressure plate fingers weren't flat and even. It's more obvious with the pull style clutch because the throwout bearing ring was visibly not flat once everything is put together. Nismo should really update their instructions to call out this specific detail. I'm not even sure the clutch as-shipped orients everything properly.
    • It ended up being that orientation of the float hub in relation to the clutch disk, when I installed it, I heard a loud click and being stupid, I decided to not take it a part and check it. The hub didn't properly align with the clutch disk and was causing the issue. Definitely an odd one! Dahtone Racing was able to fix me right up, stand up blokes!      
    • Right, but I'm saying on the stock ECU measured airmass from the MAF is no higher than stock. So it's accounting for the higher flow rate iso-manifold pressure. You just have to keep turning down the boost until you're within the stock tune's load scale. If you run off the end there's no telling what will happen. This does mean there's zero benefit to the turbos you're running vs stock, if anything it's just a straight downgrade because the transient response is worse, you don't even get the ECU's boost solenoid helping to pull the wastegate closed during initial spool, and peak power is only whatever the factory map can give you before you hit the R&R corner. On a -9 I would bet that you would have to change out the wastegate spring once you have a real ECU and you're tuning it for real. I'm not saying this is a remotely ideal state of affairs, it's just a way to keep it driveable until you can get a proper tune done.
×
×
  • Create New...