Ultimate Na Rb20

[Dan_J]

thought this was gonna be interesting but half the banter on here is sr vs rb, seems like u just posted a new thread up on nissansilvia.com

i say a better engine is a 308 and you should change series to suit ( ok i lie )

info to back up my statement goes 'here'

now would the rest of the haters keep this to RB20DE discussion ONLY

[Chris-06R]

Hmm, even though I'd love to have a go at it, the more people I discuss this with, the more it seems like an SR would be a better choice though.

An SR20VE out of the box, no mods will make ~150kw at the flywheel, and it will take alot of work to get the RB to that level.

That's the other big issue... it really is an unknown with the RB, because so few people have bothered.

[mad082]

Hmm, even though I'd love to have a go at it, the more people I discuss this with, the more it seems like an SR would be a better choice though.

An SR20VE out of the box, no mods will make ~150kw at the flywheel, and it will take alot of work to get the RB to that level.

That's the other big issue... it really is an unknown with the RB, because so few people have bothered.

yeah that is the thing. to get the rb to the level of a stock sr20ve is going to take a decent amount of work (not massive amounts, but not just exhaust and air filter). the sr20ve might be a bit more highly strung to start with, but unless you spend thousands and thousands on either motor to get them to their absolute limit you won't know which motor will give the best results. so for a minimal budget the sr20ve is going to be the better base to start with, since it already has 35kw more to start with.

[zebra]

Could always go with a 1uz-fe v8 lol.

[SKiT_R31]

Could always go with a 1uz-fe v8 lol.

pfffttt VH41/45DE

[Transpass]

Everytime the same so many threads without any useful information... if you want to tell him, that RB20 N/A power is a bad idea, why not write ONE reply. No one is interested in reading thousands of replies with the same text/info again and again... and again.

Differences in oil pumps of the SR20 and RB20 - take a look:

Picture shows the differences of the stock RB26 (top) and the N1 (bottom) pump. N1 = advanced design, not only concerning the housing, but also the cavities of the pump gears (they can be made by wire eroding). RB20 is similar to the RB26 stock design, SR20 looks more like the N1 pump.

If you want to upgrade the oil pump of the RB20, you'd have to make one or purchase an external pump like the dry sump ones.

Valvetrain:

The RB20 has a better valvetrain design when it comes to racing (high revs). Rocker arms (SR20) aren't comparable to directly acutated bucket tappets (RB). Every part in the valvetrain can represent a spring if the revs and therefore velocity and acceleration are high enough - so every rocker arm acts like a hard spring (means: harmonics and maybe cracks) . Furthermore the bucket tappets are rotated by the camshaft to reduce wear! Hydraulics have to be removed from both engine's valvetrains.

Variable valvetrains (with variable lift) are very difficult to integrate into a bucket tappet, that's why most cars with VVT use rocker arms. I think Porsche tried BTs and VVT some time ago... But a VVT doesn't matter in typical racing applications - or do you want to drive the car sometimes in the 3000rpm range and then rev the sh*t out of it up to 9000?

Bore and stroke:

69.7mm is very short stroked. Don't know why Nissan built such an engine, but when you compare it to the SR20 (86mm) and think about the average piston speed (let's say we limit it to 25m/s) then the RB20 has a lot more rpm and power potential! -> 10800 compared to 8700rpm. Ok, this is only theory, but it's possible and it's important to know. And don't tell me about the squeezed SR20s driving around at drag or drift events...

So much for that.

[_x_FiReStOrM_x_]

Was the neo engine VCT equipped? If so that would be the best base to begin with. Concentrate on headwork & flow, solid lifters, and a highly balanced bottom end to take advantage of high rpm's. Adapt some ITB's, and a clever extractor design. I guess there's many possible options, it all comes down to budget in the end i think.

[zebra]

Everytime the same so many threads without any useful information... if you want to tell him, that RB20 N/A power is a bad idea, why not write ONE reply. No one is interested in reading thousands of replies with the same text/info again and again... and again.

Differences in oil pumps of the SR20 and RB20 - take a look:

Picture shows the differences of the stock RB26 (top) and the N1 (bottom) pump. N1 = advanced design, not only concerning the housing, but also the cavities of the pump gears (they can be made by wire eroding). RB20 is similar to the RB26 stock design, SR20 looks more like the N1 pump.

If you want to upgrade the oil pump of the RB20, you'd have to make one or purchase an external pump like the dry sump ones.

Valvetrain:

The RB20 has a better valvetrain design when it comes to racing (high revs). Rocker arms (SR20) aren't comparable to directly acutated bucket tappets (RB). Every part in the valvetrain can represent a spring if the revs and therefore velocity and acceleration are high enough - so every rocker arm acts like a hard spring (means: harmonics and maybe cracks) . Furthermore the bucket tappets are rotated by the camshaft to reduce wear! Hydraulics have to be removed from both engine's valvetrains.

Variable valvetrains (with variable lift) are very difficult to integrate into a bucket tappet, that's why most cars with VVT use rocker arms. I think Porsche tried BTs and VVT some time ago... But a VVT doesn't matter in typical racing applications - or do you want to drive the car sometimes in the 3000rpm range and then rev the sh*t out of it up to 9000?

Bore and stroke:

69.7mm is very short stroked. Don't know why Nissan built such an engine, but when you compare it to the SR20 (86mm) and think about the average piston speed (let's say we limit it to 25m/s) then the RB20 has a lot more rpm and power potential! -> 10800 compared to 8700rpm. Ok, this is only theory, but it's possible and it's important to know. And don't tell me about the squeezed SR20s driving around at drag or drift events...

So much for that.

thats all very well, but Rb20 inlet ports flow all of about 120-130cfm...So Fark all, even heavily ported you would be lucky to make over 200 genuine horsepower at the flywheel, where as Sr20 that figure comes in the Autech S15 road car, with nothing but a bit of compression and some cams.

[Psymon]

But a VVT doesn't matter in typical racing applications - or do you want to drive the car sometimes in the 3000rpm range and then rev the sh*t out of it up to 9000?

This is a valid point that a lot of people seem to be missing in this thread when talking about the VVL in the SR20VE.

[zebra]

Unless you have 150 different gears in your gearbox there will be corners where you will be in the 3000-3500rpm range

[Transpass]

Unless you have 150 different gears in your gearbox there will be corners where you will be in the 3000-3500rpm range

I think every car has gear ratios which make it possible to shift down whilst driving in the 3000-3500rpm range - i've never seen a car with more than 3000rpm difference between - let's say - the second and third gear.

thats all very well, but Rb20 inlet ports flow all of about 120-130cfm...So Fark all, even heavily ported you would be lucky to make over 200 genuine horsepower at the flywheel, where as Sr20 that figure comes in the Autech S15 road car, with nothing but a bit of compression and some cams.

Please keep in mind, that there are 6 pistons.

What i've found (cfm):

SR20 - 205-245 stock, up to 275 ported (x4 -> 1100 cfm, example)

RB20 - ? stock, up to 240 ported (x6 -> 1440 cfm, look here)

[Kris..]

Plus SR's dont break Oil Pumps everytime they hit the limiter.

they just break rocker arms instead

[zebra]

they just break rocker arms instead

Haha I've been waiting for that for months

Hi5

[waxracing]

Build a sr20ve

Use the p12 head and not the p11 head.

your already at over 200hp. they come std like that.

The p12 is the one that come sout in the latest primera they made

Yes you can make them run in a rwd configuration. We did it on the jpp 180sx.

The head on an sr20 can not be ported to flow as well as a stock p12 sr20ve (p12)

Common shaft for the rockers so you will not beable to do a sr20 rocker flying off thing.

The one we peaked hp at 8800.

You will have the light weight of the sr20 and it will all be behind the front axle the car will handle alot better and also go alot faster due to the lighter weight.

its a no brainer

[ElPablo]

Any updates on this build?

[GTSBoy]

What build?