REW swap – things to retain from the RX8
 

Hi All,

I’m about to undertake a REW swap in to a S1 RX8 to be used as a dedicated track toy. I have the donor car, aptly named by my brother as the Canary.. She’s complete and for all intents and purposes, stock..
The REW is on its way to me now from an Aussie importer, it’s a fresh Japanese import from a S6 FD RX7.. It’s coming complete with manifolds, loom, ECU, box and the usual peripherals like the Alt and PS..

I’m about to start pulling the Reni out and parting out what I don’t need but I want to be sure I’m retaining everything I need AND what I might need.. The last thing I want to be doing it sourcing parts I’ve just sold..

The plan is to go with new radiator and oil coolers, use the stock PS, I already have a Microtech MT-8s with a matching race dash. Fuel is sorted with a highflow pump and surge tank ready to go..

From reading the swap threads here I’m feeling like the main thing is to retain the stock wiring, ECU and the throttle body but that’s largely it. I’ll be keeping the box, I intend on using the bellhousing with the FD 5spd to retain the stock clutch set up. The AC can all go, there’s nothing bolted to the reni that needs to be retained (though I’m thinking of snaffling the OMP for my other RX8 because I think it’s over performing..) and that’s about it..

Feels too simple, what am I missing?

Cheers All!

You have to choose what type clutch you are going to use. The FD uses a pull type clutch and the RX8 uses a push style like the FC.

The REW 5 speed won't fit without changing the drives shaft. ...and the shifter location is different

Best choice is to find an RX8 5 speed if you can. It is a plug and play solution that gives you a stronger tranny than the 6 speed

Everything else you have to decide what throttle body and how you are going to get the Power steering to work..... using a MT8 will mean you need the REW crank sensor setup....and you will need an RX8 signal for the power steering

Cheers Dannobre,
For what ever reason I missed your reply.. or at least the notification of it.

I intend on sticking with the push type by using the RX8 bell housing bolted to the Rx7 S6 5 speed. (I also have a S5 Turbo 5 spd should that fit better) I'm not worried about the shifter being in a slightly different place, have angle grinder, will cut! :) I hear what you're saying about the drive shaft though, I'll price up having a custom one made, or an extension, and weigh up the cost verses getting in the RX8 5spd.
The problem is that the 5spd was never an option here in Australia, the low power version came as an auto here.. the uk got them though and I have rotor friends there so it might be an option.

For the power steering I thought to use the gear from Full function engineering, that should, if I understand it correctly, enable me to emulate the RX8 signal for the RX8 ECU to run the PS. I'm far from an expert on the MT8 (or auto elec's in general tbh), I'm assuming there wont be an issue using the same for the MT8.
The fall back if all goes to pot is change out the ECU or just run without the PS, it's a track car after all so it's not like I have to worry about low speed corners all that much..

The throttle body is a gamble at the moment.. On hand I've got a S5 and S6 RX7 plus the RX8 with the fly by wire.. I'd like to retain the fly by wire so I don't have to worry about putting in the cable style. however if it turns out I can't get it to work I have a S5 RX7 pedal assembly on hand as well.

I've had the engine just over a week and haven't had the chance to start looking at it yet so I'm not sure what parts will be compatible with what.. yet!

I think the rx8 5spd will be your best bet, you probably want to keep the rx8 CF driveshaft and stock PPF. May have to do some international shopping, but you may be lucky and come across a free shipping one. I got mine for around $800 free shipping.

I would decide on which front cover you plan on using first, as that will likely dictate the remainder of the build if you want to stay on the beaten path. Rx8 front cover seems to be the easiest with lots of information available.

Sorry to bring a thread back from the dead but I am not yet able to make a new topic, I generally search and find the info I need so haven't needed to post much as yet. I did search this time but most info relates to S1's...

I have a S2 R3, running Mazdaedit software. I also have a REW and single turbo from a previous project which I would like to swap in. I would like to retain the factory ecu to run the engine, as I don't have massive power figures in mind (400whp max). Swap parts from Nicon-rotary seem to make the swap near painless and also retain my 6 speed trans so theres no modifications rear of the firewall nearly. I would also like to stick with the FD front plate (I will make a mount to hold the AC compressor).

From the searching I have done we need to retain -
- RX8 trigger setup (https://nicon-rotary.com/en/product/...r-for-13b-rew/)
- RX8 throttle body (https://nicon-rotary.com/en/product/...-body-adapter/)
- RX8 MAF

Being a S2 it has a different OMP setup so I might not be able to just plug it in and forget it, Premixing isn't a big deal if that's what I have to do. But I don't wanna be risking limp mode due to it not being there.

One benefit of the S2 engine is 4 injectors, same as a REW so no fab work to add in 2 more.

Have I missed anything? The intention would be to use the RX8 sensors and wiring to keep the ECU happy and reading the same signals.

Some info on the S2 OMP: https://www.rx8club.com/series-ii-af...3/#post4194887

Ummm, this thread was bumped up by me from 2016... He has his swap sorted from what I can tell elsewhere in the forum.

I asked some questions about doing it on a S2.

Msp to rew swap
 

Use the 6 port renesis harness (that you already have) that way you can take advantage of the 3 stages of fuel injection. Buy an Excessive LIM with the 4 injector bungs then buy a fuel rail (like FFE brand) with 4 ports. Your going to have to go standalone anyway.

IMO, easiest way to do swap is....

Adaptronics Modular for RX8
Front Cover for RX8 (machined to fit REW front iron).
RX8 Harness
RX8 Accessories
REW Block
RX8 trigger wheel and sensor
Excessive LIM (4 bungs)
FFE Fuel Rails (4 bung secondary)

The first thing you have to decide is what ECU you plan on using. After that you can decide what trigger you are going to use.... and the rest kinda falls into place. Personally i didn't use the OEM harness and RX8 trigger.... so I went standalone and a built harness... but there are lots that have used the OEM and plug in like the Adaptronic and have had good results.

All I did with my OEM harness was strip everything out that I didn't need... and reshield it
Basically that was most of it 🙂
I used a wire in ECU and made my own harness... using a pre-built loom the first time.... and using plugs and bulk wire the second time. There are pros and cons to both...

Depending on you end goals and who you are going to get to do your wiring...and your budget, you will have to decide what you are going to do. The harness I am working on now has north of 100 hours of work into it... and I'm still not done, so if you had to pay a shop for that you would be broke.