Rb25/30 stock ecu

[cruzy6]

Hi.
I have an r33 skyline. Was looking at rebuilding a rb30 with the rb25 head and fitting that in.
How well Would it run with the stock ecu etc.
Cheers

[bachig24u]

It will most likely start and run, but I've found with more capacity the engine needs a substantial amount more enrichment in places where it previously did not. most common changes are the load maps and cold run fuelling areas.