i need some help from the rx7 geniuses

i'm doing a s5t2(jspec motor+tranny) swap into my s4 n/a shell and right now its being a pain in the *** . the shell is pretty much stripped, except for the s4 n./a dash harness. i pulled out my n/a and dropped in my t2. i know there are a bunch of things that i need to swap out just to make the s5t2 work w/ my n/a shell.

here's a list of what i'm pretty sure i need:

-s5t2 diff.
-s5t2 driveshaft
-s5t2 ecu(jspec and iit came w/ the motor)
-s5t2 engine harness
-oil cooler??? not sure....

is there anything else i need to swap out? also i have the s4 n/a dash harness still in the car. a buddy of mine said that i could still run it with my t2 motor. but after dropping in the motor, i noticed that the harness plug and the ecu won't match up. i kinda figured i had to swap the dash harness too, but is there another way around it? i know that the s4 and s5 motors are practically 2 different motors, but is there anything i can still use from my s4 n/a?? i highly doubt though... if you could help me figure this out, i would greatly appreciate it.
thanx for looking!

 

simple way: you're going to need an entire s5 body harness to go that route.

 

alright, i did this pain of a swap and tis is what you need.

if you want to run gas and not premix you need
-s4 turbo omp
-s4 turb front cover
-s4 turbo waterpump
-s4 turbo throttlebody
youll also need an s4 turbo ecu so n332 or n333 ecu. i went with a n332
youll need the driveshaft
a turbo fuel pump
turbo drainbacktube
linkage for your new omp to your TB, you might have to make your own its a bitch to run it.

alright, now that you have the parts youll need to bypass your solenoid resistor package due to the high imp injectors from your s5 turbo motor.
are you gonna keep your smog pump and emissions? if so get ready to splice and relocate a buncha plugs and wires. i went half way through it and said eff it and just blocked off all the emissions. theres a few wires youll need to extend like the BAC a few mroe that i forget, just get both wiring and vacuum diagrams for each year. REMEMBER the wiring diagrams differ for some years within each series. like the wire colors are different between an 86 and an 87 or 88 for example. it took me a while to figure all the differences but its slowly coming togehter. by the way im only 18 and doing the swap. if i was you id stick within the series, i wish i wouldve.

you can swap alot of the plugs over from your N/a harness. but if you dont have an s4 motor that came with your car your gonna have to buy a few sensors plugs etc.

dont use your s5 turbo harness, use your s4na one. no need for your s5 turbo ecu
as for your driveshaft, mazdatrix.com makes one especialy for this swap. if your staying below 300 hp no need for a new diff.

i was gonna make a write up for this swap and i still might depends on how much time i have. i was gonna include pitures and step by step processes.
if you have any other questions just ask me.

GLHF
-mitch

 

u can use the s4 harness if i use all s4 T2 electronics meaning tps,afm,boost sensor, ecu, injectors ect....

OR you can splice in that s5 harness and use all the s5 ecu, afm,ect and do ALOOTTT of rewiring, no connector will be the same between the s4 and s5 just an fyi...

 

thanx mitch!
i have a few q's though...


sorry, i'm a bit confused....if i run premix, i use my s5 omp, but if i just wanna run gas, i can run my s4 n/a omp on my s5 motor? but the s5 connector won't match up wi th s4 omp. how is this possible? and what runs better?

also how would i bypass my solenoid resistor package? do you have any pics by any chance? or any step by step intructions?

if i were to run my s4n/a harness, would there be any splicing i need to do in order to have it work with my s5t2 motor??

i will be removing the emissions crap....so no prob there.



"linkage for your new omp to your TB, you might have to make your own its a bitch to run it. "
^^^^do you have pictures of yours?? how'd you make yours work??


wow...i had no idea you could do all of this w/ a s5 motor! thanx a buch for the info! looking foward to more info!!!!!! keep it coming!!!!

 

bump!

 

I just did the same thing to my S4 NA. Now it has a S5 TII engine in it. I went the easy way though. I used my S4 NA harness and all s4 TII electronics with S4 TII ECU and lengthened this and that to the harness to make it work. I'm running a S4 front cover and water pump etc with a S4 OMP (which is not electronic) btw. and made it work with the intake. not too hard... its finnaly all done and totally worth it

 

really? man, sounds sweet. but how did you run the n/a dash harness into the ecu? did you splice the connections? or is it plug and play?

also is there any splicing i need to worry about if run the n/a harness?? and how does you car run????

 

I left the NA dash harness alone and didn't touch anything there. the S4 NA dash harness has the same plugs as the S4 TII dash harness plugs. The S4 ECU plugs are all the same for the NA and the TII's. The only things I changed on the engine harness was about two or three wires. I'll have to check which ones when I get home cause I can't remember which ones they are at the moment. I'm currently running a N332 ECU with a modified NA harness and the engine Runs awesome with no problems. There's really not much to a engine harness once you get rid of emissions and the un needed connectors. Just leave the NA harness in your car and lengthen one or two wires like the TPS and BAC and you're good to go. And un pin the wires I'll tell you when I get home. One of the wires are the fuel pump resistor (NA cars don't have one and you won't need one) the other is the Knock sensor input to the ECU. On the NA cars that wire goes to the Power steering solenoid and if you leave it pluged in your timing will retard when you turn the steering wheel. Just un plug that pin from the ECU and its all good. Don't worry about the knock sensor system any way.. they don't work worth a ****. Bottom line, pretty much plug and play man

 

WOW! thanx alot! keep me updated on which wires you added and what not. do you have any pics?

 

will a s5na body harness work with the s5t2 ecu and engine harness?
this will be on an 87 na if it will work. my goal is to not have to convert a bunch of stuff on the engine.

 

yeah

 

one more quick one. is there no difference between the chassis harnesses from na to t2 in a specific series?

 

the coolant temp wire is in a different pin position...

 

how do you solve that?

 

Do you have a write up or anything on customizing the NA harness? With pics possibly.