I'm about to pick up an S5 TII motor (longblock), but want to run it with an 87 TII ECU. First of all... will this work?

If it does, I'm guessing I will need the following S4 items:

- S4TII AFM
- S4TII TPS
- S4TII TB(?)
- S4TII front cover w/ OMP (or I may just premix)

Please help me out here as I'm not too familiar with stock ECU differences.

 

From my understanding, it goes like this. S4 ECU you need S4 sensors. Can use an S5 short block but need S4 front cover, sensors, and MOP.

Anybody correct/add me if I'm wrong.

 

Well from what I have understood, the sensors are pretty much the same except the AFM and TPS.

With the front cover, I might just block off the S5 OMP and run premix for awhile.

 

Bump

 

Like you suggest, you'll need a series four throttle body because the series five won't fit/screw on/bolt on/plug up.

That could be overcome though. The series five has a low range tps similar to the series four. Just do a little wiring modification. Just run the three wires from the series four tps associated plug to the appropriate wires in the series five tps. You get to keep the series five throttle body that way.

You did not mention that with the series four ECU, you won't be able to control
the series five tubo output pressure. Easily overcome with a aftermarket controller. Or block off the small line from the turbo to the solenoid and let the tubo default to approx 5.5psi max.

I'd swap the series four front cover to the series five and use the series four MOP.

Yeah, you'll need the series four afm. The rest are the same ole same ole.

 

^^ Thanks for the info.

 

You can also remove the two S5 TPS seonsors from the bracket and remove the S4 tps from its bracket by undoing the little tabs underneath that clamp teh sensors themselves to the brackets. Then you can mount the S4 TPS onto the S5 bracket. It will only work in one of the two spots, you figure out which because i cant remember, but this way you save yourself some wiring/soldering.

Other differences are like mentioned in the above posts, the OMP and the S5 wastegate spring which is 5.5 psi.

 

isn't there a wiring diagram on this forum somewhere that shows you how to rewire a s5 AFM to work with a S4 ECU? I know i've seen it don't know if it was for turbo or NA or if it even matters but just thought you might be ablke to save yourself from having to buy a s4 afm since the s5 can sit at any angle

 

Thanks, but I'll probably just stick with the S4 TB and S4 AFM.

The point of this is to just get the car up and running as soon as possible before I go back to a stand-alone EMS (probably Autronic this time).