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Advice... RB25 or RB26 ???

R31Nismoid

By R31Nismoid,
in Engines & Forced Induction

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R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Ok... Long post this... but i'm stuck in two worlds

I am chasing ultimately for 300-320rwkw or so.

What i've got at the moment is upgrade to R32 Brakes, braided lines, coil over suspension, Walbro fuel pump, zorst, sufficiently decent I/C etc etc.

So in that dept i think the car can handle 300 with only more of a brake upgrade.

So these are my options that i've thought of so far for my car to get to the point.

1) Keep my RB25 and rebuild it... costs i'm not sure about.

Help or any idea here would be much appreciated...

And run with the Extractors/t04e i've got now.

On 9psi it's making 190rwkw on a conservative dyno so i think that 300 is not impossible with this setup.

I'd also do injectors/fuel set-up and all that for it too.

Cons: Are there any unforseen costs here?

Turbo wont be upto the task ?

Pros: It will be a fresh engine, i know where it's come from and what power it has been built to handle.

I've also got a chipped ECU that can be tuned so no need for aftermarket management so that's a saving to some degree.

or

2) Sell my RB25 and buy the RB26.

Now i wont get 300rwkw out of an RB26 without fiddling with the turbo's i believe, and as there are two of them it will double the cost. I've 'estimated' a cost of approx 8-10 G's will cover the RB26 conversion ?

As far as everything else i dont think i have to touch much on the RB26 like injectors or anything?

But again, i'm not 100% sure.

Cons: Engine isn't as 'fresh' as the rebuild RB25, two turbo's to replace are more expensive than a single.

More expensive parts if it does need a rebuild down the track.

Pros: Internally the RB26 is very tough. And 300rwkw on stock internals is not great drama.

But i think i have to do ECU for this also?

what are people's thoughts etc etc of this?

I hear RB25 from some and RB26 from others.

Just trying to get more opinions to get started with!

thanks guys

ash

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R31Nismoid Grand Master

R31Nismoid

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it's all up in the air!

that's been suggested... but will it REV like the RB25?

i've had an RB30et... and didn't rev.

toqure yeah, but i love a car screaming at 7500rpm.

but mm... all i'm looking for is some opinions

RIPS Contributor

RIPS

Posted
Posted

Go RB30det, they will pull 7500rpm with good assembly, we have one with a small shot of NOS that makes 350rwkw by 5500rpm, it pulls like a schoolboy, eats mild GTR's and is very cheap to repair if it ever comes to that. 300rwkw and 7500rpm without NOS would be easy......see pix......Rob

T88 ON BOARD Mentor

T88 ON BOARD

Posted
Posted

The best thing to do if the car will be for the street is...Build an RB30 Bottom end with a RB26 Head thats been machined...Strap a large Trust,GCG,HKS Turbo,Manifold and wastegate...You will Love it :D You will make Triple the power...Boost levels go Up so does Hp...Thats wat ill do

Guest INASNT

Guest INASNT

Posted
Posted
Originally posted by Sumo

Ask mattlowth (i think thats his name) He runs 300rwkw's all day long in his r33. He should be able to give you the heads up on what is required

Sumo

matlowth has rb30 block.

U might be struggling to make 300+rwkw on a t04e depending on the trim of the exhaust wheel!

Al Grand Master

Al

Posted
Posted

I would stick with the rb25det, as any other conversion would require an engineers, due to the changed engine numbers/specs. By building up a rb25 it will still look "original" and will comply with your current engineers report.

The t04e would probably not be able to make the power required, you would need something like a 600hp roller-bearing turbo. But you should have no trouble selling the t04e :(>>

You will also need: Forgies (pistons and rods), cams (to help turbo spool up faster), adj. cam gears, injectors, crank (can the std. crank handle 300+rwkw?), and someone with the knowledge to retune your chipped ecu (looks at Dr. Drift).

This information may not be accurate, as i have only little researched the topic. Someone in the know should be able to give you a better guide.

hungry6 Experienced

hungry6

Posted
Posted

i'm currently running a rb26 (built) with single gt35R with a TRUST cartridge and she get full bost at about 3200rpm and winds out to 9000rpm, appart from the associated power hikes and all, the rb26 at full tilt at big revs is something ppls have to listen to once in awhile. if 300kw is ur goal get a rb26 as a rb25 would be straining it and the last thing u want is a car in the workshop most of it life.

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