Wiring harness RB's

[yunk_s14]

is the wiring harness on a rb25 and rb20 swap the same what would have to be changed

[sebastianHoff]

not the same.

[yunk_s14]

do you know what all would have to be changed i found a s14 with a RB20 in it and it is blown and i found a RB25 for cheep cause it has no tranny and the RB25 will bolt to the RB20 tranny i just need to know about wiring it and how hard that would be you know

[SpecV_Scott]

It's not that hard. Two of my friends just upgraded their rb20'd S13s to rb25s. They had a DVD, but I think it wasn't complicated, and there are write-ups available online. I think each one spent less than a day on the wiring.

[yunk_s14]

thanks you guys

[Cool Cat Racing]

Its not near as hard as swapping it to the RB26 harness but it does involve some major changes. There are a few writeups online that will walk you through it. Do yourself a favor and get rid of the RB20 trans, its nothing more than a KA tranny and doesn't put up with much power if driven hard. Just save yourself the time and put the RB25 trans in when you do the swap.