rotorhead_fc

I've been researching into swapping my lame n/a motor for a 13bt. My car is an 86 GXL which, as you know is an S4. I have read that when you are looking to swap over from S4 to S5 that you must swap out all of the emissions control system. I am yet to find a detailed description of what exactly needs to be swapped over. Not sure if this matters but i will be most likely running a Haltech F10x engine management when i do the swap.

Also i have a question about the rear end. I know that the 13b and 13bt have different transmissions but how will the 4.10 rear end that i have now hold up in a turbo application? Im just curious to know if the gear ratios will match up pretty well or if i should be looking to swap out for a TII rear end?

And one last thing!!! I have been looking at engine overhaul seal kits and for the majority a lot of them come with the ceramic apex seals which bump the price of this overhaul kit to $1300. I was considering going oem spec on the apex seals to save a little cash. Whats the biggest setup you could expect to run on the oem apex seals?

Thanks in advance!

Aaron Cake

iTrader: (1)

Honestly, do not swap between series. If you have an S4, stick with S4. Trying to get the S5 stuff to work without going to a standalone isn't worth it.

To run the NA rear end with the TII transmission requires a custom driveshaft. If you wish to go this route, the NA rear will hold up fine. I put over 400 wheel HP though mine every day.

Majority of kits come with ceramic seals?!?! Where are you looking?

Just head to any of the rotary vendors (ie. Mazdatrix or Atkins) and get the gasket set for your engine. Then buy your apex seals from Mazda.

The OEM apex seals are widely considered to be the best out there. Not to say the aftermarket seals are junk, but you make compromises with them to gain certain characteristics.

rotorhead_fc

Hey thanks for the info Aaron. I did some research and found some info on apex seals last night and the oem ones should be fine for my application. The seal kits i've been looking at were on Atkins and Mazdatrix! ill take another look and see if they do the kits without seals.

How can i go about telling if an engine/tranny is from an S4 or S5 without it being in the vehicle? I've found a supplier online that lists the model year but a) they dont seem to have any from the S4 years and b) how do i know a supplier wont lie about the year of a motor? The supplier i found was Tiger Auto Parts, which leads me to my last question, are they reputable and is it a good/bad idea getting a JDM motor?

Thanks

Aaron Cake

iTrader: (1)

The easiest way of identifying an S5 engine is by looking at the turbo and manifold. Unlike the S4, the S5 does not have a twin scroll actuator. There is only the wastegate actuator on the compressor housing, and it has a slightly bent arm. S4 will have an actuator bolted to the manifold as well.

Now, about the apex seals. Ceramic seals are for racing only and are insanely expensive. Some are cheaper then others, but at around $300 per seal, each seal costs about as much as a full set of regular apex seals. I don't know why you are having a hard time finding regular seals. Almost no one buys ceramic seals.

Tiger has a poor reputation. Search the Canadian Forum for info.

rotorhead_fc

Hey, i went and took a look thru the Canadian forum and no dice on information about Tiger Auto. Do you have any info on why their reputation is bad? Any horror stories you've heard of?

Aaron Cake

iTrader: (1)

I searched "tiger" in the Canadian Forum:

https://www.rx7club.com/forum/showthread.php?t=758260
https://www.rx7club.com/forum/showthread.php?t=521771
https://www.rx7club.com/forum/showthread.php?t=706944
https://www.rx7club.com/forum/showthread.php?t=727258
https://www.rx7club.com/forum/showthread.php?t=704512
https://www.rx7club.com/forum/showthread.php?t=636647

Vroman

From what ive heard and researched myself, swapping an s4 motor out for an s5 motor would be really time consuming and im pretty sure i saw somewhere that the wiring harnesses are different and if that is true you would have to swap out the ecu, wiring harness, etc which is a pain in the ***. You would probably do better to just find someone parting out an "87 T2 and grab the whole drivetrain including the rear-end. You might spend about 1-1.5k but it would be the easiest and less time consuming method to go about. Plus with that you dont have to get a custom driveshaft or anything, you just pluck and place

rotorhead_fc

Yeah i've heard some horror stories about the s4 to s5 swap but the motor/tranny setups i've found have all been full swaps. Meaning full harness ecu, tranny etc. The driveshaft i might go custom or swap out the rear end. Whichever is most cost effective/doesnt suck!

If im going to be doing a swap for a complete S5 motor like i described is it still gonna be a huuuge pain in the ***? Im not too concerned about the time factor here just wouldnt want to spend wayy over the top just to get an S5 running. The reason i asked about an S5 is mostly because i cant find a god damned S4 TII setup for sale anywhere!

Aaron Cake

iTrader: (1)

The body harness is different between S4 and S5. So if you intend to switch to S5, you need to modify the harness to match. Several other things don't match up. An example would be the temp sensor.

Can all these things be worked around? Yeah. All are little things and can be solved. But it all adds up and you have to ask yourself, is it really worth the effort?

rotorhead_fc

Sweet, thanks for the info. I didnt realize the body harness was different. I just figured if i was going for the full swap with ECU and harness that it wouldnt be a problem as everything would get replaced. Thank you for clarifying!

But hey turns out after a little more digging, there are a couple of S4 turbo motors to be found. Nothing in or around Vancouver that i've seen yet, most of them are all out east so far but i've at least found a few. Definitely leaning towards the straight s4 swap, i dont mind putting the time in for the swap but id rather not be creating more work than necessary.

Oh and i came across your video on youtube of your turbo spinning after shutdown, that **** is ******* money!!