RB20E Pistons in RB20DET

[blind_elk]

I may well be rebuilding my RB20DET engine soon. Can anyone say for sure if the pistons from a RB20E will more or less drop straight in. I'm interested in them because they have a higher C/R (9.5 vs 8.5), so should get a bit better performance off-boost, while still being able to pump 1 bar.

[Cubes]

For every .5 of a CR you increase to achieve the same final compression once boost is pumped in you will require ~2.9psi less.

So you have bumped up by 1 CR that means to make the same power you should be able to do it with approx ~5.8psi less. Say 5psi for my errors.

Hence you make 160rwkw on 14psi (After AFR tune) you will make 160rwkw on 8.2psi (After AFR tune).

Give it a go, let us know how it goes.

If it fails slap a thicker head gasket in to drop the CR a little.

Should be fine though with good tuning.

I'll remind you though.

For an approx $1k you could pick your self up a R32 RB25DE that looks (externally) the same as a RB20DET.

Thicker headgasket to drop the CR. Pump the boost in.