I was debating on buying a new motor this summer since mine is blown.
I have an 88 S4 but was going to just buy the Turbo Long Block with ECU and Harness so I was thinking if it wasn't going to make a difference Id like to grab the S5 instead.

I know I will have to change out the harness and ECU but since the package comes with it either is there any other Gotcha's I need to be aware of?
Like some of the instruments not working?

I know the center set of trouble lights are different between the S4 and S5 but didnt know if they connected back into the main engine harness or another harness. I also didnt know if there was another harness that needs to mate to the proper main engine harness to tie in other accessories?

Can anyone shed any light on this?

Thanks

 

There have been quite a few threads on this and so far you haven't asked anything that hadn't been answered 100 times already....

 

Can we have 5 of these threads a week instead of 3? That would be great.

 

If you were new I'd cut you some slack but looking at your join date and post count you should know damn well how to search by now. This truly gets asked all the time and has been covered to death.

 

always use a stock harness. pick up whatever has good compression and get the n318 pressure sensor and afm ($80 shipped from me BTW) and a n33x ECU for your S4.

if you get the s5 swap your TB on it and run premix for the easiest route. sell the ECU and use the jspec harness for pig tails.

 

Please follow the link http://www.rotaryresurrection.com/2n..._s5_diffs.html
very helpful if you're contemplating what to do. I hope it helps.

 

I searched

s5 motor in s4
In the second generation section
result was 10 pages of non-related garbage

I thought maybe I needed to be more specific and search
s5 motor with ecu and wiring harness in s4

that didnt bring back anything useful either

Can you give me an example of a search term that brings back a relevant answer to one of my questions?

Walken I dont know what you mean by always use a stock harness, I didnt suggest I would be using an aftermarket one.
I also cant swap around TB's because I am switching from a NA to a Turbo motor.

 

Walken means to use an s4 TII throttle body.
You can get an s5 engine,use the s5 turbo,but take the Omp off,block it off and run premix.
Use a S4 N/a Harness,you will have to extend a couple leads like Tps and Bac connectors .
..use an s4 TII Ecu,Afm,Boost sensor.
Do you want to do the drivetrain too?..think about mating the Trans to the Diff(new Driveshaft or a TII rear end).

 

Good link Thank You

I see I have some decisions to make, I plan to change the ECU to an aftermarket so some of this doesnt matter in the long run, I also wanted to change the interior to an S5 interior so because of that I would be better off with the S5 harness BUT that was also something I planned to do in the future which means until I did all of the work I wouldnt be able to drive the car which would kinda suck.

Decisions decisions.

 

The trans is getting swapped as well.

Rear end is a LSD GTU so its gonna stay for now.

 

OK I read a bunch on that site and see why it would be a pain to swap in an S5 motor.

Next question I have is if I went with the S4 motor and harness do I need the harness?
I know I need the ECU but I read the JSPEC harness would be different since its from a right hand drive but I didnt know if the turbo computer and motor would just bolt up to an NA harness?

Thanks

 

@V8kilr yeah you need the harness, they have different ECU configurations and connectors. You may find again answers to your questions from the link I forwarded to you.