Okay folks,

I am going to try to make a long story short. I have started installing an S5 motor in an S4 vehicle. COMPLETE S5 motor with the exception of an S4 front cover so the person who owns this car doesnt have to pre-mix (its not my car, I would personally pre-mix).

I have assembled the motor, and am getting the oil injector lines all squared away. But there is a part of this swap I cant figure out:

Which Vac assembly to use? the S4 or the S5?

Far as I can tell, the advantages to the S4 is that its plug and play (to the engine harness), HOWEVER, it requires some modding for mounts, and vac lines need to be re-ran.

S5 avantages? Plug and play (to the motor), vac lines are already lined up. Disadvantages? Where to plug the S4 harness wires (the vac solenoids). I am trying to keep the motor running in emissions compliance.

Confused yet? Cause I am!

Any help is greatly appreciated!

Jarrett

 

Also, the S5 vac assembly will ease in the installation of the S5 upper manifold.

I wonder if its possible to run an S5 ECU, S5 ECU harness, and S5 motor in an S4 car? Hmmm...

Jarrett

 

Seems to me you'd want to use the series five ECU. The main reason is the VDI and the auxillary ports. You've got to trigger them somehow. And you want to because the VDI gives you some more wothwhile hp.

Uh, I've never seen a series five. Just talking. Not walking the walk here. I'd hope that all you would have to do is R square the engine harness. Nope. That'd be too easy.

But if you did that, you'd have to put the series five front cover back on, and hope the metering oil pump actually works.

Better you than me!

I don't have a series five wiring diagram so I can't help any.

 

****, didnt think of that. With no signal from the OMP, the S5 will go into limp mode. I think that my solution will be to run the S4 intake and vac assembly, sans the EGR (the S5 has no EGR). Ive studied both wiring and vac diagrams to the point that my head is splitting. I think the main issue thats hanging me up, is that I am in an emissions state, and I am trying to maintain emissions.

I dont see a way to trick the S5 ECU into thinking the OMP is okay, but I havent looked at the signal flow for that area yet.

I have read all about the people running S5 intakes on S4 motors, lots of modifications, which isnt a problem. Just time consuming.

If emissions wasnt a problem, this would be a breeze.

Jarrett

 

IF its an s4 CAR, forget teh s5 ELECTRONICS. They will NOT plug into the car's main wiring harness (under dash, drivers side). You cannot use the s5 ecu, engine wiring harness, injectors, OMP, etc. The plugs between series are different shapes, and different ECU pinouts.

Ive said it before and Ill say it again, once you open this "pandora's box" one thing leads to another, then another, then...

 

To make it easy to finish, i would stick with S4 stuff all the way (except block itself).....

S4 front cover already on
S4 vac routing (easy, bolt in for S4 TB - not too much vac stuff on block anyways....)
S4 LIM and UIM
S4 harness and ECU