rx7T24me

I've been reading anything I can regaurding differences in the S5 engine and the S4, but still not sure about compitibility of dropping an S5 turbo engine and all into and S4 TII car. Someone has told me that I could use either the 87 computer (original) or the 89 (with new engine). I would think this would be problematic with the different oil sending units, rev limits, hp gains, and other things I've read about. Also was told that if I use the 89 ECU I need so change out the switch harness? Assuming ignition. Should I just go and get a standalone EMS for it?

Thanks guys! I'm really confused right now.

YearsOfDecay

If you can afford it, and don't have to pass emissions... go for the stand alone.. you'll be able to do a lot more with the car in the long run.

Another thing you need to worry about is that the 89 ecu is going to be looking for an electric OMP an the car.. if it doesn't see it, it'll go into limp mode and mess things up.

I guess you COULD drop the s5 turbo and engine in there and use all the wiring, sensors and controls, enough people have made this swap that SOMEBODY has to know exactly how its done...

rx7T24me

Well, I wouldn't say that I can really afford it, but if a standalone is the only way to do it i'm stuck with it. Basically It's a full 89 TII long block that has been put in and not hooked up yet. Word is it has the 89 ECU in it and wired in already.

Will the standalone systems not pass emissions? I do need to be able to pass them.

Thanks!

RETed

Easy to "fix" with a male bullet connector, a short piece of wire, and a female spade connector.

There is no change in rev limits.

There is almost no change in power if you eliminate the boost controller integrated into the Kouki turbo harness and ECU.

The ECU's do no swap out - the harness plugs are totally different.

Do you have capabilities to tune the unit?


-Ted

HAILERS

If the series four and the series five connectors, although different, have the same type connector/socket on the end of each wire (read termination), then maybe it's possible to just depin the plugs and then install the plug that will fit the ECU that you are going to use.

You could repin it correctly by comparing the pinouts for the series four vs the series five. That pinout is found in the FSM for each series car.

RETed

I think the two largest plugs have offset pins on the ends so they will not physically swap unless you brute force them in?

Realistically, they are not swappable.


-Ted

rx7T24me

I have an old laptop, but wouldn't know what to do.

It sounds like the correct plug could be put on the end, but I wouldn't know how to do it. Would I be better off to continue looking for an 89 harness assuming the 89 ECU is already in the car?

Right, sorry. I meant red line since I've read the S5 goes to 8000rpm and S4 something like 7000 (don't remember exactly.

Is this for wiring in the electric oil sending unit of the S5? Soudns easy enough.


-Thanks again guys!

RETed

I would not recommend a stand-alone unless you're willing to pay someone else to tune it for you.


That would be easiest.


For NA's, yes.  All FC turbos have 7kRPM redlines.


Yes, for the oil pressure sensor located under the oil filter.


-Ted

rx7T24me

Think I read somewhere it's around $300 to have someone tune it. Would this be a better solution to using a fuel controller like the HKS AFR? The car has intake and will have a Bonez turboflo with RB Cat-Back. It's a daily driver / autox.

What do you do for a harness when using the standalones? I think some come with a harness, but do others use the stock harness?

Guess I'll Just keep looking for an S5 engine harness for it for now. I'm waiting for guy to send me the ECU model number so I can verify which one really is in the car.

(sorry I'm such a newbie with computers)

RETed

Um, any computer might get you into trouble with SCCA rules.
You might want to check if your mods might start moving you into a higher class.

Yes, the stand-alone EMS is the ultimate device for engine control.  Due to the flexiblity, it can also get you into a lot of trouble; blown engines is not uncommon.

All will offer their own wiring harnesses; this will require custom installation.  Some will have options for plug-in kits.

There's nothing wrong with using your Zenki harness (and fuel injectors) on the Kouki engine.  This might be the cheapest and easiest option at this point?  If you do go this route, you just need to address the throttle body/TPS and oil metering concerns.  Throttle bodies will swap over.  You can always go pre-mix; if not, you need to switch the front cover and oil metering pumps (and throttle body) to use the Zenki mechanical oil metering system.



-Ted

rx7T24me

Good point - hadn't thought of that one.

Well, I only have the S5 engine and no S4 engine or parts. So I'm going to have to convert the car to the engine. I'm not having much luck finding an S5 harness though I think this is all I should need to make it all work.

Many Thanks.

rx7T24me

should I consider a fuel controller even if i stay with the stock ECU? I read somewhere that you can get pinging if you upgrade the exhaust and intake without correcting the fuel mixture or something.

Thanks again

(I'm curious since I haven't heard this about piston engines so wondering if it's a bigger issue with a rotary.)

rx7T24me

I have a parts guy that is telling me I can't use the 89 ECU, harness, and engine in an 87 car. I guess he just wants to sell me parts that he already has? Seems everything I've read here says it should work ok.

Just wondering if I've missed something.

rx7T24me

Ok, apparently an 87 NA ECU was put in, but still have the original 87 TII ECU to put back in. I have read that you need so swap some parts on the engine though to get it to work and I don't have any parts off the original engine. I feel like this keeps getting more complicated. What do you guess think it the best way for me to solve this now?

sorry I must sound really dumb at this point.