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

    • I'm back from the dyno - again! I went looking for someone who knew LS's and had a roller dyno, to see how it shaped up compared to everything else and confirm the powerband really is peaking where Mr Mamo says it should. TLDR: The dyno result I got this time definitely had the shape of how it feels on the road and finally 'makes sense'. Also we had a bit more time to play with timing on the dyno, it turns out the common practice in LS is to lower the timing around peak torque and restore it to max after. So given a car was on the dyno and mostly dialled in already, it was time for tweaking. Luis at APS is definitely knowledgable when it came to this and had overlays ready to go and was happy to share. If you map out your cylinder airmass you start seeing graphs that look a LOT like the engine's torque curve. The good thing also is if you map out your timing curve when you're avoiding knock... this curve very much looks like the inverse of the airmass curve. The result? Well it's another 10.7kw/14hp kw from where I drove it in at. Pretty much everywhere, too. As to how much this car actually makes in Hub Dyno numbers, American Dyno numbers, or Mainline dyno numbers, I say I don't know and it's gone up ~25kw since I started tinkering lol. It IS interesting how the shorter ratio gears I have aren't scaled right on this dyno - 6840RPM is 199KMH, not 175KMH. I have also seen other printouts here with cars with less mods at much higher "kmh" for their RPM due Commodores having 3.45's or longer (!) rear diff ratios maxing out 4th gear which is the 1:1 gear on the T56. Does this matter? No, not really. The real answer is go to the strip and see what it traps, but: I guess I should have gone last Sunday...
    • 310mm rotors will be avilable from Australia, Japan, and probably a few other places. Nothing for the front can be put on the back.
    • The filter only filters down to a specific size. Add to that, the filter is AFTER the pump. So it means everything starts breaking your pump even if its being filtered out.
    • Just like in being 14mm too small (296mm) makes it not fit, being 14mm too big (324mm) it also won't fit. You want to find the correct rotor.
    • @GTSBoy Ok so that was the shops problem...they showed R33 rotors on R34 page and i did not know 296 do not fit(and are for R33) Yes i bought "kit" with rotors and pads. Pads are ok(i have GTT calipers front and rear). They have some 324mm but no 310mm. So i dont know if they would fit. I have 17inch LMGT4s So another question. Can i fit those in the rear or they are just "too" big for that?
×
×
  • Create New...