HIrotary

injector wire harness are different so ill be using S5 TII injectors. my following questions are:

would the S5 TII injectors fit into the S4 TII fuel rails? if not what would i have to do? would there be any clearance issues?

w.sen

iTrader: (8)

they fit

RXSpeed16

iTrader: (41)

You need to use s4 lower grommets. This thread shows the part. https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s4-vs-s5-secondary-injector-differences-839869/

HIrotary

i seen that thread,that thread is for the NA intake manifolds. ill be using the S5 TII injectors on a S5 6port with the S4 TII fuel rails.

RXSpeed16

iTrader: (41)

I haven't done this swap, but I think you will be fine. Mazdatrix lists different s4 and s5 (but no turbo/NA) part numbers for the lower spacer, but they seem to be interchangeable.

HIrotary

hopefully i dont need to change out the spacer. we all will find out when i do it lol. thanks

but anyones knowledge/help to this thread would be greatly appreciated so keep posting.

w.sen

iTrader: (8)

i belive as long as your use s4 turbo manifolds with s4 fuel rails everything should work out..

rxat2012

iTrader: (3)

im looking at doing this also do you need to us the TII wiring harness and ecu