rb25 into rb20 prepped car..how easy?

[bubzb20z]

So my s13 has a fully functioning rb20 in it currently wiuth a small knock.

I was debating on putting my rb25 longblock into the car and use the existing set-up from the rb20 (wiring, ECU, SAFC2, etc) to power the 25.

ANybody done thiss,m Im sure some of the sensors would be different.

I would use the topfeed fuel rail and my rx7 460cc injectors if I could

Thanks for any help

[DRFERO]

to use the top fed injectors on a 25 ull need to use the whole inlet manifold off the 20...as rb25s have side fed injectors...run the same ecu and wiring loom and injectors and just bolt all ur 20det stuff onto the 25 block/head and ull be away

[squbafreak15]

how would tht ecu work w. variable timing

[DriftingisLame]

Definately wouldnt be able to operate VTC. You'd need a S1 RB25 without VTC.

Am I correct that S1's have no VTC? I'm 99% sure.

[virus77]

20 intake will not bolt on to 25 headall rb25det have vtc ( i have a s1 with vtc)rb20 ecu wouldn't be able to control it anywayYou can probably get away with wiring/modifying an rb25 with an rb20 harness and forget you ever had vtc

[dohclover]

if willing would you part it out and if so how much for the wiring harness