pretty soon i'm planing on dropping a TII engine into my n/a 86. right now im saving up for parts and am gonna start buying things soon. i plan on getting the racing beat rev-TII exhaust system eventually but don't want to save an extra 800 bucks if i dont have to. basically i was wondering if the s4 n/a exhaust can be bolted on to an s5 TII engine untill i can afford the new ehaust. thanks in advance. -justin

 

Sorry to threadjack but I actually have a problem like that.

I have an 89 TII with a dp (unknown), stock main cat, and the apexi n1 catback.

I also have a 90 GTU (all stock).

I was wondering if I could take the cat back off of the GTU and bolt it to the stock cat on the turbo car so I can sell the A'Pexi (because I plan on getting an RB catback).

I believe my question could be summed up as "Do both the turbo and non-turbo models of the S5 body style have the same exhaust from the catback, or atleast one that connects the the same cat the same distance from rear bumper.

 

Are you aware you will need to completly rewire the car in order to run a S5 engine in a S4 chassis? The exhaust should be the least of your worries but you will need a TII downpipe to make it fit.

 

FRFC3S- no worries, ur fine dude

RB_eater- the wiring on the ENTIRE car has to be redone? i was under the impression that only the engine wiring harness and ecu would need to be changed. what about if i were to swap an s4 13bt, would that allow for only the engine wiring harness and ecu to be changed and the rest of the cars wiring would be ok as is? thanks for theadvice on the dp tho.

 

Think about this:

 

The front harness plugs won't match up to the ECU. Engine harness won't have the right connectors, and the S5 engine harness won't match the front harness. I don't know the specifics since it's been a long time since I checked it out, but it's a real pain in the ***. You can either rewire the car, or go standalone.

Edit...The catback should fit but you'll need a custom downpipe and midpipe as I'm sure you don't want to use the stock cats.

 

ok, that seems like an excessive amount of work for me. what about if like i said earlier, i swap an s4 turbo II engine into the car? will i only have to get the wiring harness and ecu (and obviously other mechanical parts) instead of redoing the whole car?

 

Yup s4 tII motor will go right in (for the most part).
Before purchasing the harness, Run a search for HAILERS and harness. I am actually in the process of doing this swap and will let you know how my s4 se runs with the stock harness and s4 t2 motor.

search and research, there are several other parts you will need as well.

john

 

thanks all around for all the help, you guys saved me from a big dissapointment and lots of trouble.

 

If you put a series four turbo in the car, leave the non turbo EM harness on the new engine. There are but a couple of wiring changes to be made when doing this verses installing a turboII EM harness in a non turbo car.

The PROBLEM using a turboii EM harness on a non turbo car (series FOUR), are the two plugs that interface b/t the EM harness and the FRONT harness. There are more than a couple of wires that would have to be rearranged in those two plugs to make things work 100 percent right.

You can use a TurboII EM harness on a na, but you need to ask "is it really worth it?".

 

alright hailers i have a question, i have owned 3 tII's and 2 n/a's. both n/a's were s5 and all turbos were s4. i just converted a 91 n/a auto in 87 tii by gutting both and putting every last inch of the s4 into the s5. that obviously works great. but now i am building a turbo motor to swap into my brothers s4 n/a. we were gonna use the s4 tii ecu and modify the s4 n/a emish harness (well all emissions will be eliminated anyway along with twin scroll and whatnot. i am already aware of the knock box and sensor issue and was going to add those components appropriately, but will i have any other issues that you are aware of? i am not using a s4 tii guage cluster however we are leaving the s4 n/a cluster in place.

 

I did an S4 swap and used the turbo harness. It's more work to do, but yields the same results. So in the end, don't do what I did.

HAILERS, how many times have you posted this advice? I bet it's a bazillion.