rb motors

[darren]

Hey Darren here i am putti

ng a rb 30 into a 260z ther are many rb motors in oz cheap let me know what you want and i will get you a price

[dohc]

Hey Man,

I'm in Adelaide too and I'm a little undecided whether to go for an RB30 turb from a VL or the RB20 from a skyline. Any thoughts? I've got a 260Z 2 + 2 and want to go to Efi...

Also any thoughts on which ECU to use? I was thinking of using a Delco from the VR/VS commodore as they are easy to program and relativly cheap.

Any advice is useful

Thank,

Ross.

[Ivan]

I could be wrong about a lot of this but just as an educated guess:

Go for what ever is the cheapest over there, they both have about the same hp (150kw).

The RB30 looks a little inefficient (only putting out 150kw for a 3L 7psi turbo), and with turbo engines improving the efficiency improves the hp significantly. With an intercooler and a better ecu it would probably put out about 180 - 190kw.

The RB20 is DOHC and it would sound better than the RB30 being able to rev higher but it would start getting expensive if you wanted more than about 270hp out of it (they run about 10psi standard).

But at the same time how much hp do you really want for a 1050kg car?

Another idea is to put a RB20 or RB25 head on the RB30 if you wanted to.

There is a formula I got out a turbo book that takes the efficiency, cubic inches and psi to give a predicted hp:

hp=efficiency*cubic inches*(14.7+psi)

The formula is not perfect as when you run more psi through a turbo it gets hotter and the efficiency reduces (the 14.7 is the air pressure), it also doesn't take into account the pressure drop through an intercooler.

But just as a approximation the Garret style T03 turbos on these engines don't like being more than 15psi intercooled or 10 to 12 psi not intercooled. So by just playing with the wast gate you could get about 261hp out of the RB20 (@15psi) and about 255hp out of the RB30 (@10psi - any more than that you would probably want to invest in an intercooler or the engine will get too hot)

[dohc]

Thanks Ivan.

Currently the RB30 is still cheaper and with a lot more in the way of after market goodies but I see things changing soon as cheaper imports take over.

I think I'll bide my time and go for the RB20 down the track

Cheers for the input!