I am trying to identify this engine. I have an RB25DET engine,
On the front it says,
"Japan
75T "

On the back vin# is
084460A


I believe it is from a Laurel. And does anybody know the difference between Laurel and Skyline RB25 engines? For sure this wastegate is set to 3psi, compared to 7psi with the skyline. What else is different? I think injectors are smaller, ECU is different, maf is smaller, etc... but I am not SURE. I need to VERIFY.

Would help if you posted a picture.

I had an RB20 from a cefiro.. one thing to check is the blow off valve. Laurels and Cefiros didn't have the blow off valve on the cross over pipe while the Skyline does.

This is a question better suited for the RB forums, but I'll chip in a bit of my knowledge anyway. I'm feeling nice in this new year. LOL

Eikon, one thing about the bypass valve. It was only the 20's if I remember right. The 25's were the same across all the platforms that used them. Stagea, Laurel, Skyline to the best of my knowledge.

On the 25's, I'm not 100% sure, but I do know that on the 20's, the Laurel/Cefiro engines had slightly smaller turbos. The oil feed/return lines were also smaller. I know from experience as I swapped a turbo from an R32 GTS-t to my C33 Laurel. Injectors were 270cc and there was no stock bypass valve. Stock (Laurel turbo) boost was 0.7bar, same as what the Skylines wastegate was set at, but different size.

Gold Digger wrote:This is a question better suited for the RB forums, but I'll chip in a bit of my knowledge anyway. I'm feeling nice in this new year. LOL

Eikon, one thing about the bypass valve. It was only the 20's if I remember right. The 25's were the same across all the platforms that used them. Stagea, Laurel, Skyline to the best of my knowledge.

On the 25's, I'm not 100% sure, but I do know that on the 20's, the Laurel/Cefiro engines had slightly smaller turbos. The oil feed/return lines were also smaller. I know from experience as I swapped a turbo from an R32 GTS-t to my C33 Laurel. Injectors were 270cc and there was no stock bypass valve. Stock (Laurel turbo) boost was 0.7bar, same as what the Skylines wastegate was set at, but different size.

The wastegate on this RB25 is set to 3psi, thats like .2 bar
I will get pictures tomorrow for sure.
If I checked the size of the turbo (via a number on it) would that help indicate if it was a skyline/lauren engine?

3psi? That is friggan low!!! I know my friends old C34 RB25DET Laurel was 0.45bar stock. Not sure what the skylines were, though. 3psi makes me think something is wrong with that turbo or wastegate.

I know what you mean. I couldnt believe it either, there must be some kind of electronic solenoid in the vehicle from the factory to raise it slightly.

Well, if I remember right, I've heard people say that the R33 and R34 Skylines with the 25DET did have some kind of boost control solenoid. I know my GT-R has one. It can raise the boost to 1bar, but there is a factory installed orifice in one of the hoses off the solenoid that limit the factory boost to something like 0.7bar.