Ok so i have been doing tons of research on this im going to boost my stock motor in my 91 ef hatch. its got a dpfi motor in it right now. in order for boost i have to convert it to mpfi right? now if i buy a si wiring harness is it plug and play or not? what do i need to plug the si harness into a mpfi motor and have it work perfectly with the subharness? do i need to be odb1 to boost cuz thats what a couple of my friends said and i told them no but and insite would be awesome thanks guys

 

look under the faq's here:
https://honda-tech.com/zerothread/1508680
there's walkthrough's and what not regarding a lot of things.

 

youll need a couple other things for MPFI swap. like resistor box, dist, and ecu if your staying obdo. everyones gonna say go obd1 for turbo because of the better tuning programs available for obd1, such as crome etc. look on pgmfi.org if you havent already

 

Well you need to look in the FAQ link at the top of this section all the info is there....

You don't have to go MPFI but it is highly suggested if you want to boost the motor, more air needs more fuel...

You need to modify your stock harness, you can't just swap in a new harness and expect everything to be indentical becuase they aren't...I believe all you will need is the injector harness but as long as you have the injector clips you can make your own harness...and for easy of getting cheap injectors for boost use a resistor box...DSM turbo injectors use one

You don't have to convert to OBD1, Turboedit is an OBD0 tunning program which you can use

Read the FAQ there is all the info you will need in there...