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You have to use the R32 RB25DE inlet manifold but can use the R32 RB20DET inlet plenum.

Port sizes are different.

The R32 RB25DE doesn't use piston oil squirters. Piston oil squirters are good and will allow you to make a little more power on the stock pistons. One has to look at the VLT's to know for street use they are not a necessity.

I'm not running piston oil squirters in my rb30det but I run forged pistons.

If I were to do what you are thinking about doing, I would slap a set of GTR rods and crank in the r32 rb25 block. :)

Everything else in the r32 bolts up and it literally looks like an RB20DET, you could not tell unless you drove it or pulled the head off and measured the bores. ;)

I say do it. You won't regret it.

My RB30DET with 9psi on the stock turbo made 176rwkw, the rb20det required 15psi to make 164rwkw.

Goes to show how much better the rb25 head flows, not suprising when you see the rb25 inlet valves are 5mm bigger EACH!

Oil squirters are block mounted. You can machine, drill and tap them.

RB25de plenum only differs in that it doesn't have the nipple for the bov's inlet plenum air pressure. You can simply T off the carbon canisters hose if need be.

You only have to look at the two motors to realise that the r33 plenum is designed different and will not bolt up no matter how hard you try.

Pop down to your local wrecker, bring a digital camera and check out rb25det, rb20det and an r32 rb25de.

I am considering an RB25 from an R33 for my R32 GTS4. My car has a 4WD sump which means that I can use a $1,000 RB25DE from an R33 GTS4 or a $3,000 RB25DET from a Stagea. I would prefer to spend $1,000 and put my RB20DET exhaust manifold and turbo straight on.

I wonder what the difference in power would be. Does anyone have any ideas?

Thanks. I'm not being cheeky, but why is it important to use DET pistons?

Could I change the head gasket to change the comprssion ratio?

The difference in the cost of the two engines is about $2,000. If I need to do more than change the head gasket that gap begins to close... I imagine it isn't cheap to have someone change the pistons?

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