I just picked up a write off S5 t2 parts car, i was wondering if there are any resources on here outlining the swap. both cars are complete and in running order so i have a full t2 drive train/wiring harness and a minty gxl s4 with a blown coolant seal.

 

The FAQ has links to cover this. You can also refer to this recent thread (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s5-t2-swap-help-plz-937324/), but ignore everything turbospdant posted because it's wrong.

 

Haha fair enough, i will keep that in mind. thanks

 

in that thread, there seemed to be a lot of talk about hacking the turbo ecu to the interior or using an s4 ecu etc. i am sure someone has swapped the uncut interior harness so the stock s5 guage cluster/ heater core/ everything else is used in the s4 shell. or am i totally off base?

 

There are really only 2 non-hack-job ways to go about this:

1) Retain all S4 NA harnesses. Source S4 TII front cover, intake manifolds, TB, all sensors and ECU (N332/N333). Make the simple modifications to the S4 NA EM harness, bolt all the S4 TII parts onto the S5 TII block. This turns the swap into the much simpler S4 TII -> S4 NA. The link in my sig. and the FAQ covers that.

2) Remove every S4 NA harness from the car, and replace them with S5 TII harnesses. This will introduce a bunch of little problems where some components don't exist, or plugs are not the same shape anymore, etc...

#2 might sound simple, but it's a serious bitch. Those that I've talked to that actually pulled it off wished they would have either gone S4 TII, or chosen option #1. You'll have to strip both cars down to get to everything you need. That includes removing both dashes, lots of interior panels, etc...

 

well thanks a bunch for your input, i will certainly have to do some more homework before i start ripping either car apart.

 

I have done option 2 and it is no fun and is not worth it. Just take the keg from the s5 and slap some s4 turbo parts and call it a day.

 

if you want 2 sell the s5 gauge cluster let me know i need it badly.

 

question: why would you want to switch back to the S4 intake manifolds?

 

You wouldn't. Forget I said that . I can't think of a good reason to get rid of the S5 LIM/UIM, since the ports would match the block. Swap the S4 TB onto the UIM, and you'll be able to use the S4 TPS.

Something that might be added to that quick list is an S4 water pump housing. I don't think the S5 version will work due to mounting differences for OMP clearance.

 

said what? (hee hee)

 

well against all better judgment, i am going ahead with the shell swap. both cars are gutted and both engines are being pulled pronto. the entire s5 interior harness has been labeled, and i will start the process of re-wiring next week. i feel that any different/non compatible parts can be either modified or swapped. i will give it my best shot and keep you up to date on my progress!

 

Hey good news!
the entire chassis has been re-wired, the s5 turbo engine has been cleaned up (with emissions removed) and dropped into the car. after the engine was wired up, the car flashed no problem. i need to adjust the idle and work out a few bugs but for the most part things are looking good.
i have yet to test the rest of the electrical system (power windows, lights etc. etc. ) but after i do so, i can soundproof and put the interior back in!

i hope to have the car back on the road in the next month or two i will post a bunch of pics when its all done

 

Any ideas about my idle? i suppose it must be a vacuum leak because the car will simply stall if the revs drop below 2k. i only have a downpipe bolted up to the turbo could it be a lack of back pressure? by the way my emissions delete did not include the thermowax or bac, they are still intact. does this sound like a common simple problem?

 

Engines don't need backpressure to run. That's just a myth. You can unbolt the whole exhaust manifold and it'll run, but you may blacken the engine bay .

You're most likely looking at a vaccum/air leak. If rewired the car with S5 harnesses, you can probably check for codes too: http://www.johnr.com/cpucodes.html.