Tell me about the RB25 ?

[sx boy]

Hi guys ,

I'm after some information and have a series of questions for you .

How easy is it to fit an RB25 and its gearbox in an s14a ?

Which is best , series 1 or 2 ?

Whats safe power on standard internals ?

What are this engines inherent weak points ?

Whats the best turbo to run strong reliable power and torque whilst maintaining drivability ?

How easy is it (or not lol) to get all the electrical system working properly ?

and finally is there anywhere that does a drive in drive out service with a good reputation and who's not gonna rip me off ?

I know there's a lot of experience of this conversion on here so please enlighten me .

Your inputs and advice much appreciated .

regards

Matt

[igralec]

Fairly easy, gearbox needs a bracket as two of the holes for the mount don't line up, and engine fits ok if you use the r33 crossmember and bend the servo lines to fit. Wiring is the most problematic. You might also need to grind a part of the bonnet where it can foul on the throttle body and also is not much room for the visco fan unless you cut the slam panel to get more room.

best would be NEO because it has a better valvetrain and a 7500 rev limit, but the s1 and s2 are very close, same HP same tuning potential. I'd just get the one you can get with less mileage and generally in a better shape.

around 400-450hp on a good map should be doable if the engine is in good shape.

At higher RPM there can be oil drain problems from the head, also ringlands can crack, AFMs can fail, almost all RB25 have coilpack issues (best bet is to make the coilpack brakets from thermoplastic or buy new/aftermarket ones), missfires and the ECU is very sensitive to mods, if you fit an exhaust, filter or FMIC, it will retard the timing at certain rev ranges and make the powerband shite. Also not many off the shelf chips available and there is a bit of hassle to use nistune on the R33 engine.

probably a hybrid standard turbo with steel internals (the standard ceramic exhaust wheel can break at 1 bar which pretty much limits power at around 350 on a standard turbo) is good gor a stage 2 setup, which should put out around 400ish hp. There aren't many bolt-on turbos for the RB25 because of the strange 6 bolt exhaust flange.

Probably not that difficult if you're handy with wiring.

I'm sure there are services like that in the UK, probably even some of the traders.

[jumpbike]

find a breaker and get the whole front sub frame, bolts straight in so no need to make mounts up for engine at least, not sure where that leaves the gearbox but I've got an r33 box on an sr20 and the R33 gear box cross member bolts straight up.

[Dave270r]

This has been covered many, many times. Read through the projects section. Loads of places will do the conversion. Buy a complete R33 gtst as a donor and sell the bits you don't need.