Hello everyone,

Did a search but all I found was S5 --> S4 Chassis. I am wondering what are the major modifications/problems I will be looking at if I take an S4 TII engine and install it into my S5 vert. Reason I ask is because I found a really good deal on one and want to know what I will be facing if I go this route.

Thanks!

 

I know someone here has done swaps between series before. I know for a fact the engine will go right in, along with it's transmission. I am concerned about the wiring harness on my s5 vert fitting the s4 TII engine and any other problem with doing the swap this way. What do you guys think?

 

switch front covers with electric omp one. use your injectors, and your good to go. Also s5 throttle body. I have a s5 tii front cover for sale also.

 

By injectors you mean oil injectors correct? Is that pretty much all of it? What about the wiring harness for the engine?

 

http://www.rotaryresurrection.com/2n...o_s5_swap.html

This has been covered many times. If you must swap between series, use as much of the electronics that match the chassis as possible. In this case, you'll want all S5 sensors, ECU & wiring.

 

I looked at the website, it didn't tell me much in regards to putting an S4 TII engine into an S5 Convertible which has an S5 NA engine. It is helpful in only going from S4TII -> S5TII or S4NA -> S5 NA.

Since the S4 has a mechanical OMP wouldn't I be able to just use that rather than the S5 electronic OMP off my NA? The engine will be coming with the S4 wiring harness and S4 TII ECU and S4 TII Tranny.

Thanks for the replies so far.....

 

You're going to need to piece together information from that website and threads on here. The whole point of using all S5 electronics and wiring is to make your swap be basically the same as a simple S5 TII - > S5 NA swap. The thread I link to in my sig has some info on that kind of swap, but it's mostly S4.

You can use the mechanical OMP, S4 front cover and S4 TB, but then you would still need to have an electric OMP plugged in (to the side) so the S5 TII ECU doesn't throw you into limp mode.

The alternative to getting an S5 TII AFM, MAP sensor, OMP, TPS & ECU to connect to your existing S5 NA EM harness would be rewiring all over to adapt an S4 TII EM harness & ECU. You would also have to adapt the S5 NA front harness to work with the S4 TII ECU. Everything is arranged differently, and the plugs aren't even the same shape between series. It's a huge amount of work, if you mix and match S4 & S5 electronics and wiring.

 

I get what you are saying now, so in order to have everything plug and play I pretty much need all the S5 TII electronics and also S5 TII ECU, but if I want to keep all the S4 TII I would need to rewire everything correct?

I don't want to mix, match I just want to toss that sucker in there and use everything it will come with (s4 harness, ecu, tranny, ect...). I was planning on running a stand-alone with my swap eventually so the whole rewiring is something I was expecting eventually.

I've never rewired a car, but I am comfortable working with electronics and it wouldn't bother me. When you guys rewire the engine do you guys reuse the old harnesses that connect to the sensors and wire to the standalone from there?

How about the electrical system such as the interior lights, ect... I am assuming that is all part of a separate harness so I won't need to touch that correct?

 

When I say "mix and match", I'm talking about mixing S4 & S5 electronics and wiring. To just drop in the engine w/ , you would basically need to start studying both wiring diagrams & control unit pin outs in the FSM emissions section. You'll have to completely rearrange the connections from the ECU to the front harness, and from the EM harness to the front harness. The wires and pins don't line up at all; you'll be changing just about all of them. The rotaryressurection link has some info that can help figure out how to rearrange some of it to work with the S5 cluster, which is connected to the front harness.

I don't use a standalone, but most of them use a brand new EM harness and sensors. You'd get to redo all of the ECU to front harness and EM to front harness connections again, since the new harness will also be arranged differently.

Interior lighting isn't associated with the ECU or EM harness. It's mainly the cluster that will be dependent on getting the rewiring correct.

 

as stated above, you'll need to swap over the S5 front cover.
All S5 sensors and electronics must be used.

 

By EM harness you mean engine management correct? So from what I understood there was that if I use the stock S4 TII ECU I have to rewire everything from the front harness to the ECU, or if I go stand alone I have to do the same thing, (which I would expect)? This is only in the case I keep being stubborn and not want to use s5 components though right.

But besides this everything else will be alright?

I might have to post up a new thread, but i'm still wondering if the people who use a stand alone like MS reuse the old sensor plugs from the harness and wire back to the megasquirt from there?

 

That's the gist of it. EM = engine management. The only other thing I can think of is alternator wiring. On S4 NAs, one of the alternator plugs (for the warning lights) is on the EM harness. So, if it gets replaced with a TII EM harness, a new connection must be run. I'm fairly sure you'll run into the same dilema on an S5 NA, but I haven't looked into it.

Attached is a pic from the FSM. I highlighted the rough path of the front and EM harnesses. It's not perfect, but FEM-01 & FEM-02 are the connections between the two harnesses. And you can also see that both of them plug into the ECU.

 

Easiest way is to go standalone.

 

Ok I think I wasn't understanding the whole front harness until I saw that diagram, I was thinking it was all one harness. Exactly what components run through the front harness and what other ones through the EM harness?\

It looks like the front harness just controls the headlights in that diagram, while the EM controls all the sensors and engine components. Am I right?

 

It's not that simple at all. I just highlighted the rough path each harness takes. The front harness connects to a ton of things; not just the headlights. It includes: the charging system, the coils, the CAS, the instrument cluster, the starter cut relay (alarm), the circuit opening relay (fuel pump), fuel pump resistor relay, etc...

 

Got you, thanks for posting those up. I'm going to open up a new thread on the MS section to see how some of those guys have their system wired up...