Advice Needed

[IslandBoy]

Guys, I am running a RB20DET in my C33 and i think my engine is dying. I think Iam hearing a slight knocking. Anyway I am running a VG30DET turbo with z32 AFM and upgraded ECU. Should I jump to an RB25DET using back my gearbox or just continue using the RB20. and continue to modify. Iam looking for a little more speed on top end.

[David_NISMO]

Correct me if I'm wrong, and someone will. But if you go with the rb25 you'll have to get a new gearbox and driveshaft.

If you rebuild, get some forgies and a cometic gasket so you can slam some boost in there, that'll give you your top end for sure.

[Joe]

the 20 transmission will bolt onto a 25 engine no problem.

[David_NISMO]

"doh"

[Carl H]

you'll either need the r33 loom for the rb25det or rewire the existing rb20 harness to work on the rb25 and wire in some kind of rpm control for the vtc to function properly, then after that you'll need a retune to compensate for the larger motor and vtc.