S2 engine in an 86 shell

[pwengland]

Some help please from the experts.

Have a 944 race car with an 86 shell and an S2 engine.

Car runs and races great but after hankering for a bit more HP, I went down the path of a supercharger. Decided to run VEMS rather modify all the other bits. I ordered VEMS based on the S2 engine and Peep has delivered everything as such.

Once we went to install everything we realised that the car currently has a 35 pin harness rather than the 55 pin setup for the S2.

I have managed to find an S2 55 pin harness which we will fit to the car but the question that's been bugging me is, how has an S2 engine been running perfectly with a 35 pin harness ?

Everything I have read says that if you are going to fit an S2 engine to an ex 8 valve car then you need to bring the whole harness over from the S2, sensors, DME and flywheel.

I’m just wondering whether to make things work they may have put an older non S2 flywheel and therefore I won’t be able to get the car to run just by changing the harness.

Anyway, any thoughts on the subject are greatly appreciated.