ok well heres my problem.i called a guy the other day to ask about a 87 t2..he said that he has put a 91 turbo2 engine it,alls he needs is a wiring harness...ok well heres my question

do the s4 & s5 t2 engines have the same wiring harness but diffrent ecu's...

and are the ecu's the same...cuz my of my memories(not too well) is that the s4 and s5 had diffrent internals,,not computers....but im a noob and i need help badly

 

I know that they have different ECU's and I think they have diff wiring harnesses.

 

do you/anyone know the diffrence,like can i splicve wires and stuff, cuz i cant find any wiring harness's for a s5 t2..like anywhare

 

Radically different harnesses and ECUs.

 

ok,so now i have the idea,,,,does anyone know whare i can get the wiring harness for a s5 t2?

 

If the car is an 87, you would want to locate a engine harness for an 87 and use that on the S5 motor.

Of course that would also mean swapping the front cover out with one from a S4 and the MOP, since the S5 MOP will not work with a S4 ECU.

 

what if the car already has a s5 ecu in it,can i just get the s5 wiring harness(thanx for the help too)

 

Well then you will also need to replace the dash, front, and rear harnesses with a S5 coupe harnesses, or build a custom harness that would work with a S4 body

 

holy......,this is a lot of work...why would i need to replace the dash?its not like it could be that much bigger?could it???and wouldent the front and rear harness come with a harness if i bought it from someone??

 

dash harness.. the S4 dash harness wires different than the S5 one...

Not the actual dash...just all the electronics.

Which is why if you wanted it simple you should be using a 87 Turbo engine harness and ECU and change the front cover and MOP

 

well the guy started itas a project car...and didnt have the money to buy it and since your here,,like i said im a noob..what a blower motor and can u put a s4 NA trans into a s4 turbo 2???

 

Here you can look at the pin setup on a S4

Here you can look at the pin setup on a S5


As you can see the pin outs are totally different. This means the harness is totally different. So you can get the pin outs per the FSM and redo them and so on. Or you can adapted the S4 harness to the S5 motor and take the proper means necessary to convert the S5 motor to run properly on a S4 ECU.

No they have different computers and harnesses. The motors are the same really. The S5 has a little higher compression and a little lighter rotor. Them OMP is electric and the UIM is different looking.

 

ok,like it said im a noob,and i dont know what half the abbreaviations mean(im not a mechanical genius,or know anything at all really) i took auto body rather than auto mechanics...so i know what looks good..now i would like to learn.. but heres my taking on what you said...so il lrestate it to make sure i got this right..and another question,do the (mounts? whare the harness ends go to..(oppsite from the ecu)) go to the same place on a s4&s5?? and if so,i can use the s4 wiring harness and change the ends to a s5 end to fit into a s4 ecu????

 

No.
? No. If you have a S4 harness and computer they will plug right in. Why change it to a s5? You would end up with a non working setup.

The best thing to do is use all S4 stuff and adapt the motor to comply with S4 standards. Even this is more work then I want to do. I would premix it to save the cover plateswap headache and use a high imp motor harness from a S4, use a S4 PS and S4 AFM, use a S4 TPS and you should be done.

All the abreviations are found in the FAQ sticky as well as links to the FSM for all of your diagram needs.

 

so even if i have a s5 engine,i can still use the s4 wiring harness and ecu..if this dosent end up working ,ill just say skrew the car..cuz like i said,im no mechanic,,and i dont have a garage..so im essentially skrewed

 

well then atitude and will is evrything. I must say just move on and don't wory about it anymore.

 

well my problem is,its not expoensive,but id have to sell my car tog et it,and i need a car to get to work,ill probably talk to the guy,see if he can do it,ill give him extra money,otherwise im gunna go else whare(cuz i need a daily driver)

 

well then atitude and will is evrything. I must say just move on and don't wory about it anymore.

 

well then I would say you are way over your head trying to do a mixed series swap...

sell the car and get out now.

 

Ack! NEVER, EVER buy a project car when you need a daily driver. Not that I'm implying all Rx-7s are project cars, but they are all older and need work.. YOUR 7 is DEFINATELY a project car, though. You don't want to do something like custom wiring when there's a short deadline of "gotta learn how to wire things so I can get to work on monday!". Not a good idea at all.

Let this one pass for someone who is looking for a project car.

 

lol..ok thanx for thehelp guys