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Rb25det & Disco Potato Aka 2860rs

Black_CSR

By Black_CSR,
in Engines & Forced Induction

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limpus Mentor

limpus

Posted
Posted
Hey Stao.. i would be interested in ur further testing and gladly would accept.. what do u suggest?

Why would you agree to do R&D for a product you have bought which has promised results...R&D should be done by the manufacturer before a product is released...not after its sold and failed to meet requirements....

And to hypergear...its BS that a 2530 won't hold 20psi because the rear is too small...even a 2510 or a GT-SS will do 20psi...

hypergear Grand Master

hypergear

Posted
Posted
Why would you agree to do R&D for a product you have bought which has promised results...R&D should be done by the manufacturer before a product is released...not after its sold and failed to meet requirements....

And to hypergear...its BS that a 2530 won't hold 20psi because the rear is too small...even a 2510 or a GT-SS will do 20psi...

Limpus this specific turbo is not released. I'm testing lots of different combinations on mine and few others for the best result. and in general speaking there is not best results, there can only be better results. All prototype units has been offered at a discounted price with the tester knowing what it is.

HKS2530 can not hold 20psi by 7000RPMS internally gated on a stock RB25det setup. There are plenty of sheets proven it can't, find me one that can.

STATUS Grand Master

STATUS

Posted
Posted
1st lot of graphs compared to the 2nd - its a lot better...

However 4000rpm you still only have 140rwkw, for a peak of only 230rwkw on 21psi IMO that is poor.

You'd expect that kinda power delivery from a 600hp turbo - not a 400hp one.

.86/.82 is a bad rear end choice for a start. Any why boost would be nosing over that hard is amazing... Certainly I'd have issues with that.

As an example have a look @ the two graphs below simply taken from the RB25 dyno thread.

180rwkw @ 4100rpm, that is a whopping 40rwkw more than your setup for pretty much the same end result, and less boost as well to boot.

http://www.skylinesaustralia.com/forums/post-a279850-

This next graph... 500-550hp GT30, making 160rwkw @ 4000rpm. 20rwkw more @ 4000/40rwkw more in the top end

http://www.skylinesaustralia.com/forums/post-a288761-

Now my aim was not to bag your setup - simply to highlight there is a pretty big problem.

I'd be investigating the boost control firstly - try get it holding 20psi to redline.

If it wont (even with the gate held shut), then it's just a poor turbo.

Ramp rate is also something to look @ i had a GTR in here with a dyno graph from a well known shop and it was only possible to replicate it with an artificially high ramp rate (brings it on alot sooner).

Unfortunately ramp rate is used alot to skew results.

Not saying that this is the case here but it brings up the old adage that the only good comparison can be done on the same dyno.

simpletool Mentor

simpletool

Posted
Posted

Wouldn't a low ramp rate bring on a turbo sooner?

Stao - I was thinking of a 52T 2871 with a T2 0.86 rear on an adapter. The price of those things is sooo cheap. I'd estimate full boost at 3200rpm and should be enough to make 330rwhp.

STATUS Grand Master

STATUS

Posted
Posted
Wouldn't a low ramp rate bring on a turbo sooner?

Stao - I was thinking of a 52T 2871 with a T2 0.86 rear on an adapter. The price of those things is sooo cheap. I'd estimate full boost at 3200rpm and should be enough to make 330rwhp.

nah, think 1st gear vs 4th gear... 4th gear more load = quicker spool.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted
nah, think 1st gear vs 4th gear... 4th gear more load = quicker spool.

Oh ye look no doubt - but i don't think any ramp rate is going to alter the 40rwkw odd that this is down on the midrange.

20rwkw, maybe... but 40rwkw when talking about what, 140-170rwkw, thats a fair percentage ;)

  • 2 weeks later...
liampire Contributor

liampire

Posted
Posted (edited)

Hmmm, well here is a dynograph of my RB20DET with a Disco Potato, .82 rear. Almost reaches 300HP. I used an adaptor purchased from Garrett to mate the T25/T28 flange to the T3. I am looking to change the rear housing to .64 for more response. This is 1 bar boost.

dsc00374uz.jpg

Edited by liampire
  • 3 months later...

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