So I think I'm going to drop a s5 motor with all the smaller parts still connected around it including wiring harness, ECU, and other components including manifolds and what not into my s4.

I do have another s4 motor sitting around with all the stuff on the block, emissions and what not if I need to transfer anything from that onto my s5 block.

My question is what problems am I going to run into when I try to drop my s5 longblock (minus the transmission) into my s4?

O ya everything is N/A too...

Thanks!

-Jon

 

you will need to re-wire the engine harnesses or replace all the vehicles harnesses with S5 ones

 

Ok that will be no problem, since i do have access to the whole engine harness and an s5 ECU. So that is it though nothing else will be a problem.

Thanks for the input

-Jon

 

I don't think you understood.

The S4 and S5 harnesses are not compatible.

They do not plug in together.

They don't even have the same plugs in most cases.

So if you use a S5 engine and engine harness and ECU in a S4 car, nothing will plug in.

You will need to customize the harness to make it work in a S4. You will need to re-pin plugs, move and add wires as well as run some wires.

 

You're best bet would be to drop the S5 block in and use all your S4 manifolds and wiring.......

Unless you're doing this simply for the VDI on the S5 then that will get it done.

 

just use s4 wireing and swap the omps out, or say screw it and run premix

 

O ok. some of the electrical components that aren't on the engine won't plug into the s5 harness, crap didnt' think about that.

Thanks for the replys

-Jon

 

What is the VDI?

 

Ok my questions exactly paralled this thread so instead of opening a new one i'm expanding on it . . .

how hard will it be to splice the s5 ECU and harnesses to the s4?, wiring diagrams should suffice right?

 

Major headache.. S4 car=s4 engine and electronics s5 car= s5 engine and electronics.. dont try to mix and match and splice if you like your sanity...

 

I did S5 short block with S4 front cover and S4 stuff and it works almost good ... juste a little problem when I'm over 5500rpm.

 

yeah i'm afraid to remove that front cover . . . the motor worked well with the S5 setup and i'd like to keep it functional

 

Do you want to run premix or not? If you do, you won't have to put the s4 front cover.

 

not i prmixed for a while and hated dealing with it. I'd like to figure out a way to use the S5 ecu sucessfully . . .

 

You'll need to rewire everything ... I think it's possible to re-use s4 wires but you'll need to fit the s5 connectors. You can also run with the s4 ecu with the s4 harness and the s4 front cover ... that's not hard to do. You take off some bolts and the main pulley nut and you replace the front cover.

 

from what i hear there's some issues with me possibly dropping to torrington bearing, and theres an oil o ring that i have to **** with . . .
plus id like to have the 8k redline and the VDI/ air pump powered aux ports etc. . . i've already pulled the harness and the ecu.

 

If you can fit the s5 engine harness and s5 ecu with s4 car harness just do it, you'll have your s5 oil metering pump.

 

RotaryResurrection

 

nothing there helps, i've read through it before. I have to splaice the s5 ecu connector to the needed wiring on the s4 body harness. . .

 

The only writeup I've seen of this was done by LUCIU$ (a friend of HIGGI's I think), on this thread: https://www.rx7club.com/showthread.p...7&page=2&pp=15

It's do'able using the series five EM harness and matiing it with the S4 Front harness. Talking using the S5 ECU in a series four car.

If memory serves, LUCIU$ has done a couple of cars like that. Like I said *memory*.