Im trying to sort out the alternator location for my v8 944, Im using a mk4 Escort alternator, with a 5 rib belt, and can get it in almost the same location as the original porsche unit.

Question is about its 'gearing' I have 2 crank pulleys I can use, one would have it spin 8% slower than the porsche, and the other would be 13% faster, both in relation to engine speed.

Im leaning towards the faster as this would ensure there is charge at tickover for the efi etc. and as its a torquier engine is likely to be driven at lower revs.

Any advice, view points would be welcome??

Cheers.

Pete.

[Edited on 14/1/17 by r1_pete]

whats the rev limit on the escort, and your 944?
if the escort limit is lower, then you need to use the pully that makes the alternator run slower.