So what is all involved in this swap? Im going rtek 1.5 no mop *getting error code, and i have s4 waterjacket on my s5, so it has clearance issues wiht the s5 omp*, so im either gonna go block off and premix or grab a s4 omp.

It being cable driven via throttle body correct? any modifcations needed to bolt up the cable to the tb?

 

I looked into this when my MOP took out my ECU. Pain in the *** to accomplish this and you will spend some bux. IIRC you must change out the front cover and convert everything on the front to S4. Then, you have to find a way to rig the linkage to the TB.

And now, you will use much more oil, as the S4 system is much less precise, therefore it over-injects oil compared to the S5 Electronic system.

You may have a fried ECU as well. I did. I eventually just bought a used MOP, did a very thorough diagnostic, (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s5-mop-ecu-failure-diagnosis-710938/) bought a used ECU from a friend and went back to enjoying my car.

 

hmm i hope the ecu didnt go out.. its a n370 and i see those things can be pricey used. lol

i pulled the car off the road, driving another car now til the rtek chip comes in.

 

block it off and premix. leave your OMP hooked up so the ecu doesn't go into limp mode

if you are getting an rtek just block it off and premix.

 

I you look down in that thread, there are details how to repair the ecu. Mine was burned *EXACTLY* like the one showed in the thread. No one knows if the Rtek chip will allow for a burned ecu to function. You will be the first to try. If it works, then please let us know! If it doesn't, then you will either have to repair the ecu or buy a new one.

 

Change the front cover, omp, and lines. Use a bicycle brake cable for actuation. You may have to do some trimming to make the S5 water pump housing fit back on.

 

debating if i should grab the omp off a friends s4 tII since im grabbing his lsd.. but you guys say the front housing will need to be swapped.. hmmm..

i have a s4 water pump housing+ pump on my s5 *pretty sure thats how my s5 omp went out because the clearance between the s4 pump housing is really close to the omp*.

I may just go block off, id have to order a block off kit asap tho...

 

do your engine a favor premix that bitch and have some comfort knowing the whole engine is getting lubed just not the center of the apex

 

i think they mean front cover, not front housing.

My MOP was bad on my S5, but I was going to premix anyways, and so I got a rtek 1.8 with no mop and blocked that POS......man oh man do I love S4s......

 

The center of the apex seal gets the hottest so it needs the most lubrication. Even still the rest of the apex seals get lubed just fine as the oil that enters the metering lines on lower manifold mixes with the fuel. Of course there's nothing wrong with premix. It's just a pain to do all the time.

The lack of center lubrication was the main reason so many Renesis engines failed. They have 2 oil injectors per rotor housing and each is pointed outwards to the corners with nothing lubing the center. That's why there are dyno inconsistencies, mileage inconsistencies, and reports of engines failing in hotter climates. It led to Mazda reflashing the ecu several times all in an attempt to deal with the lubrication issues. Their final solution was to add a 3rd oil injector to each housing on the '09 RX-8's. They also got all electric omp's with a dedicated one running the center oil injectors so they could vary flow between it and the outers. The newer engines dyno higher and are more consistent.

 

if you get a s4 throttle body and the OMP linkage you dont have to use the bicycle cable.
I am using a S4 on my S5, but I also use a 2 stoke oil resevoir.
Mine was very involved to finally get working right.