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Rb20det


rednut
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Can anyone comment on just how tough the RB20 is? DO they have any inherent problems? Are they just as bulletproof as an SR20 say? What kind of limits can they tolerate before one needs to start modifying the internals?

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problem: turbo has a ceramic exhaust wheel which, although it spools up quicker apparently, it is prone to failure past 14psi...

problem: i (and others) have had issues with cold starts, may need more than one crank to get going...

other than that they're a great engine and can revvvv all day and it loves it! (it told me)

Waz.

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ahh

well they are good for up to 200 rwkw preety easily,

but after that is gonna cost u alot.

they are preety heavy breathign engines so you will need a breather fitted to it if you are goign to modify it alot, like my dads

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The RB series engines are superior to the SRs, anything SRs can do RBs can do better :D

Im not too familiar with the RB20, but i know the RB25DET pretty well, if the RB20s are anything like them .. which they are.. than youve done well buying one

that being said though, there not indestructable. Certain things will destroy/damage an engine, you just need to know what to look for

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The valvetrain of the RB20 is superior to the SR, and you wont have that noisy startup prob that the variable timing SRs have.

As a basis of an engine i think the RB20 is better. Generically if ppl are building up an engine a 2mm overbore on 6 cylinders is going to give you a bigger displacement hike then on 4 so no need for custom cranks if after a 2.2L.

RB20s also rev a little better, but this may also mean despite having a superior valvetrain, new valve springs may be warranted if you want to be venturing beyond 8,000rom regularly.

I have done 164,000kms on my RB20 and still runs well and is as smooth as ever, and some 3,000ms have been done on the track.

The only drama i have is last track day i got a little excited chasing down a 996 Porsche and upped the rev limit to keep up on the straights, and now on startup (goes away after about 3 seconds with oil pressure) i have this ticking noise, so my valvetrain is getting a little tired. :Oops:

Also the R31 GTSR raced by Gibson Mtorsport used std crank & rods, and from what i have read the R31 GTSR RB20 and R31/32 RB20s use the same crank & rods (Someomne may be able to prove me wrong though) .

So you know the rods are good for 8,000+rpm , at 1.7bar and 450hp (at the engine) Of course thats not using std valves, cams and valvesprings, but an indicatipon of what could be expected from an RB20 bottom end with forged pistons.

GO THE RB20 ;)

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i have heard that the RB20 is good for 500hp at the flywheel on stock internals :s

unsure how true this is but this person know the RB20 pretty well!!!!

i also believe that the stock pistons are actually forged but have inperfections hence that is why they go rather easier because of those inperfections

anyone heard this before?

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i have heard that the RB20 is good for 500hp at the flywheel on stock internals :s

unsure how true this is but this person know the RB20 pretty well!!!!

i also believe that the stock pistons are actually forged but have inperfections hence that is why they go rather easier because of those inperfections

anyone heard this before?

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i also believe that the stock pistons are actually forged but have inperfections hence that is why they go rather easier because of those inperfections

I've heard that too; though it is probably a good bet to replace the 'rods on most cars by the time you'll need to replace them on the RB20.

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problem: turbo has a ceramic exhaust wheel which, although it spools up quicker apparently, it is prone to failure past 14psi...

problem: i (and others) have had issues with cold starts, may need more than one crank to get going...

other than that they're a great engine and can revvvv all day and it loves it! (it told me)

Waz.

With the cold starts, I find if i switch the key to On or whatever, and leave it for a few seconds then start, it will start fine. Gets the fuel pump going and shit.

Might not be your problem but it works for me.

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I dont think you will find the pistons are forged, im fairly sure they are cast.

Oh and another plus if you are chasing big power is that they have a steel block which helps with distortion if you are chasing big numbers, where as the SR20 has all alloy, which is lighter but perhaps prone to fail under high cylinder pressures/temperatures.

I suppose a good question is how much power can they reasonably crank out witout going broke chasing numbers, and i have a feeling that after about 240rwkws (assuming std they have 110rwkws) then that is close to 300kws at the engine.

They could very well be reliable at higher power levels but i suspect the std parts start to hurt power, smaller bore means smaller combusiton chamber, means smaller valves so wont be flowing as well as RB25/26 heads. And at those power levels the cams and breathing are likely to be conservative. Your relying on 2L to get the party going with the sort of turbos needed to produce over 240rwkws making the engine rather peaky

So with the right parts and budget i cant see why an RB20 cant make 350rwks... but that would mean bigger valves, cams, pistons, rods, perhaps GTR crank etc etc. At those sorts of extremes your basically re-engineering an engine.

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  • 6 months later...

I have a GT2530, 3inch exhaust, FMIC, and a chipped ECU...and at 1 bar boost, make about the 200rwkw mark. The RB20 responds good to mods

I thought i'd share this pic of my RB20. Just fabricating a steel induction pipe for the turbo and doing away with the stock rubber one.

RB20DET + GT2530 = :rofl:

Scott

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Nice pic scott

I have a RB20det in the good old R31 and she has

-GTR cooler with 2.5inch piping

-Nismo fuel reg,GTR injectors and Bosch 040 fuel pump

-Stainless exhaust manifold

-HKS GT2535 and 3inch exhaust

-Z32 AFM and Apexi PFC

-Catch can

-Now all it needs is a big tune and see how 20psi goes

If it does'nt do 300hp+ it's going coz i've spent to much time and money on her.Will keep you guys posted on how it goes.

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VLRB20DET it takes a little to get it going but around high 3000rpm it want's to boogie.It is hard to comment at this stage coz it's running so rich.

Looking at the standard RB20det turbs no wonder it spooled up so quick.

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ahh

well they are good for up to 200 rwkw preety easily,

but after that is gonna cost u alot.

they are preety heavy breathign engines so you will need a breather fitted to it if you are goign to modify it alot, like my dads

They aren't heavy breathers.. I've seen one that had blow by at 70,000km's but mine with 1.1bar regular servicing, plenty of fuel and no detonation has seen 161,000km's with no blow by.

All the intake pipes are still perfectly clean no oil is being sucked in from the rocker covers.

The RB20's are known to be tougher than the RB25DET motors.

Its got to do with the design with the piston (ringlands), plus they run a slightly lower static comp.

As mentioned previously they are only really good up to around 450hp as the head becomes a restriction.

The RB25/26 inlet valves are 5mm bigger each - thats 10mm bigger overall duh. :(

There is no way you can match that with oversized valves in the rb20t.

Thats unless you make it to rev then it will be passing the amount of air to make the 450+hp.

The only problem with rev's is it makes the car a pig to drive around on the streets.

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