[ZeroNZ]

Hey guys,

when building an RB25, are there any major differences between the 25DE and 25DET that I should be aware of? I know about the minor differences like oil squirters and intake manifold being different on some 25DEs, but for purposes of putting in forged pistons and rods (for a turbo build) is there anything else I need to be aware of?

Cheers guys

 

[goldtooth]

Hi, do you mean you're going to use the DE engine and add a turbo? The compression ratio is different on the non-turbo engines and as I recall it's in the shape of the piston crown. So if you put DET pistons in the DE block to keep using it as non-turbo then the CR will be too low. But if you put DET pistons in and do a turbo conversion then that's good as the compression ratios will be ok for running normal boost levels. Other issues are that the DE block doesn't have tappings for turbo oil and water feeds and returns although there are easy ways around that. If it's a NEO engine, the con rods are the same as in the GTT and GTR and has solid lifters. The inlet is quite different on the NEO too.

 

[ZeroNZ]

Hey sorry, I should have clarified. I am possibly buying an R33 GTS4 but since they are non-turbo I want to build the engine and have it turbocharged. I was just wondering on the side of differences between the two, because as far as I can see, if I put RB25DET forged pistons in a RB25DE block they should work? Was just not wanting to make an expensive mistake! Haha

 

[goldtooth]

OK, that makes sense. I just kept the standard DE pistons for my turbo conversion but I've just been chatting with a guy on SAU who's doing a turbo conversion on the NEO DE block and is using CP forged pistons which will fit fine and much better than the DE ones for running decent boost - same would be fine on the earlier series engines too.

Do you already know about the differences with the missing oil/water feed and returns? If not I'll add what I know.

 

[ZeroNZ]

I think I know what to do about the water and oil feeds/returns, I'm thinking it would be roughly the same process as plus T'ing the engine (but not RFBing it haha).

I'm planning on running a GTW3476r on it as I can get a decent price on one, and I'm aiming for about 500hp out of it, so I want to go fully built with aftermarket control.

Cheers!