I have an 89 Civic si with stock D16. For classing purposes, I need to swap down to a D15B2 engine. Both are PGM-FI. Will the si harness match up? Will I need to swap the ECU as well?

Also, would an si 5 spd. 4.25 ring and pinion fit into a 4 spd. diff?

Thanks.

 

its like the oppisite of doing a mpfi conversion. With that motor you will only have 2 injectors instead of 4. as for the trans question i am not sure.

 

ive never heard of anyone doing this before. youd be better off getting a dx or std, they are lighter and already have the dpfi.

you will have to modify the harness and swap the ecu, not sure about the tranny though.

 

you can just use your current IM and wiring and everything will work fine. any sohc d series can replace any other....its just using original manifolds.

 

y do u want to do this againg? its like a 15hp loss

 

Thanks to all who responded. I think I have a handle on what I need to do.

FYI, the "downgrade" is due to a class (that I want to race in) restriction that doesn't allow the si engine.