I *think* I may have found a light alternator that could be made to fit. Pegasus racing offers a racing alt that looks like it would fit and it's a bit more than 6 lbs lighter.

dave

 

I doubt anyone is on the edge of their seats waiting for an answer to this question....that said just in case someone ever searches and ends up here.

I found two possible alternators but both look to be a no-go in the end -

- I found a racing unit that weighs only 6 lbs but it doesn't have an internal voltage regulator. Running it without one seriously risks cooking the ECU so that's a non-starter.
- the alternator from a 1985ish Geo Metro could be made to fit. It weighs 7 lbs and it has an internal voltage regulator but it's not rated to spin as fast as the S2000 engine would spin it. Given the pulley sizes the alternator will spin at about twice the engine rpm and the Geo alt will not be happy spinning at 18,000 rpms.

So....I'm back to the start on this. Thanks for your time and input.


dave

 

Switch the pulley out, I've swapped out pulleys one loads of alts, including this mazda one to slow it down (to 12krpm, or they cook), it's surprising how many pulleys are interchangable across units.