S4 T2 Swap Into S5 Body
 

Ok i have researched for the past two days and cannot find a thread or any info on swapping a s4 t2 into a s5 n/a chassis.
My s5 motor lost compression at the rear rotor, my friend has a s4 turbo 2 car that got hit by a falling tree and is selling the motor and the drive train for a pretty good deal, im trying to figure out if i need to do some mods on my s5 or will the s4 turbo motor bolt in with out any problems.
Any info would be greatly appreciated.

wish I could help but truth us I'm not entirely sure what the best approach is, but in my opinion you have two options.

1. switching everything to series 4
2. adapting everything to work with s5 stuff

Rotary > Pistons

Engine will bolt in no problem the mounts are the same.

To run the turbo 2 transmission you need the turbo 2 driveshaft, differential, and axles. You need the clutch and flywheel as well but i assume that would be on the engine. And make sure you get the transmission mount as the n/a mount will not work.

The main problem you come into is wiring. The s4 - s5 stuff is not simply plug and play. It takes a lot of custom wiring to actually make it work and your still stuck at the factory boost on the stock computer.

The general acceptance is that if you want to run a turbo motor you need to buy a standalone ecu. Like a motec, microtech, megasquirt, or haltech. I currently run a microtech ltx8 as i got it for $400 and got the car tuned and driveable for about 1k. Although the microtech is somewhat ancient technology and doesnt have all the tuning bells and whistles as other standalone ecu's it still handles the constant abuse i throw at it.

Thanks for the replies! I will be putting the turbo ecu from the other car into mine for the wiring harness. Will I still have problems doing that?

Yes you will still have issues. The s5 body harness plug will not fit into the s4 turbo ecu. You will save yourself a great deal of work if you get an s5 turbo engine.

Damn...well I really don't want to pass up this deal...my buddy is willing to sell me his turbo motor, tranny, drive shaft, rear end and all the wiring for 1k. I just think of be a fool for not jumping on this.

Then i would jump on it. Like i said it will all go in no problem. You just wont be able to run the factory ecu and factory engine harness. You will have to buy a standalone system. The money you will save buying your friends s4 turbo setup will be spent getting an aftermarket ecu. The plus side to buying your friends motor is you know it ran instead of taking your chances on a imported jdm engine.

Hmmmm....well I guess that is whats got to be done...do you suggest any standalones?

Im running a micro tech ltx8. Like i said before it doesnt have all the bells and whistle as some other higher end ecu's have but im still completely happy with it. Its on my drift car and it sees 6k-8k rpms on a constant bases and has been fine for over a year now. You can get them used for about $500 maybe more depending if you get one that already has a premade harness that you could just plug in. The main part would be getting someone reliable to tune the car. That is THE MOST important part of having a safe running car. Only have someone tune the car that has done rotarys before they are the only ones who will know how to properly tune it. You could look at rtek ecu's but i know absolutely nothing about them but people do use them.

I may look up some diagrams from both s4 body harness and s5 body harness and take a bullet and see if a can adapt my harness into the s4 just till I can save up again to buy a standalone and get it tuned. Im sure it can be done but im sure its gonna take some time.

you can make it plug an play, but you will need s5 t2 map sensor, AFM and ECU.

you will use your existing S5 NA harness on the S4 turbo engine, you will need s5 t2 injectors or rewire for s4 t2 ones. you will also need s5 t2 throttle body, but you can use the NA s5 TB to get the car running.

running simplified vacuum setup without the rats nest is the way to go

That doesn't sound too expensive...now will the s5 na AFM work?

you will be able to turn the engine on with the NA AFM and drive it around but the fuel delivery will not be adequate.

AFM, MAP, ECU is a combo of electrical components meant to work together. on every rx7 model, s4na n326-7, s5na n350-1, s4t2 n318-32, s5t2 n370-74, all numbers on these 3 items are matching for a reason.

I am just finishing this swap, a s4 t2 into a s5 vert.... the easiest route for me was replacing all s5 with s4. I have no plans anytime going to a s5 motor so I was fine with it, but literally nothing matched in a vert. I could have traced/spliced/repinned but I already had the car stripped, and just finished parting a s4 vert so I had everything I needed. but rear harness, battery, front harness, dash harness, engine harness, even the doors nothing is the same s4-s5.... my car is essentially a s4 in a s5 body now.

Yeah I had thought about doing the same but my Blown motor that's still in the car I'm going to save and make a project down the road so I don't want to go totally s4...thank god some more people replied to this thread I was worried no one had done something like this. Thanks for all the replies everyone they are helping out alot!!!

nobody mentioning that if you turn the engine into an S5,the S5 Harness needs the S5 Electric OMP...and that means the engine does too.So it needs a Front cover.

that's true,

but can also have the s4 omp installed, just keep the s5 OMP will be plugged in, to prevent the limp mode.

That is true,but if he has the s4 Omp with the s5 TB it will be useless,as you can't hook it up,so may as well go OMP Delete and premix.If he stays with the S4 TB then he has to worry about the TPS.
I am thinking if he still stays with an S5 Harness he can not worry about the OMP and go to Premix IF he gets an S5 Based RTEK (digital tuning, inc.).
That way he gets the appropriate s5 TII Sensors,afm,injectors(or switches connectors and runs HI s4 TII injectors),All on the s5 harness.

Really there is a variety of ways,but there is not a Cheap way if you start putting a different series engine in a different series car.

Couldn't I just rig the s4 OMP to run open all the time? I new a guy with a Bridgeport 10AE who ran a s4 OMP but had rig it to run fully open cause ran a carbureted setup.