Rb20Det Box Onto Rb25Det Engine.

[Caddy]

Hey guys, just wondering about the interchangeability of an rb20det box onto an rb25det engine.

Is there anything that needs modifying or do they just bolt on?

Dave

[GTSBoy]

Will bolt on. Will die quickly.

[89CAL]

LOL

[blind_elk]

Will die quickly.

Depends how you treat it. My (R32) GTS4 gearbox is sitting behind a RB25DET (180@all 4), and it is still in pretty good nick.

Clearly, if you want to do 7k sidesteps of the clutch, then it's unlikely the box will last long, particularly if you have a mega clamp pressure clutch setup.

[GTSBoy]

Depends how you treat it. My (R32) GTS4 gearbox is sitting behind a RB25DET (180@all 4), and it is still in pretty good nick.

Clearly, if you want to do 7k sidesteps of the clutch, then it's unlikely the box will last long, particularly if you have a mega clamp pressure clutch setup.

Not the same. RB20DET box is same as NA RB25 box. These are much lighter and weaker than the big boxes. RB25DET box is essentially the same as the GTR box. And so is the GTS4 box. It's the same basic thing as the GTR/RB25 even though it was stuck behind an RB20DET in the R32s. On that basis, of course yours will be fine.

[-Jimmy-]

I don't see how this is any different than someone modifying an RB20 and leaving the standard box on (which happens a lot). A close to stock or mildy modified RB25 will be fine with the 20DET box if you know how to drive.

[GTSBoy]

Who has a close to stock 25 these days?