I’ve replaced my marelli unit with a Denso that comes with a 57mm pulley rather than the stock 48mm unit. For track use only does this get the rpm’s down where they need to be?
It represent a reduction of around 16% in alternator RPM.
Dave
Hi Dave
That puts it at about 18krpm when the enginge is turning 8krpm. Is that still too high for a track only car?
18k is about the max any alternator is designed to safely spin at. It should be fine but if you go down to your local electrical rebuilder and have them pull out the parts books, there is a pulley that will fit the Denso unit that I believe is 62 or 67mm. That will slow down the shaft speed a bit more. With the larger pully the stock belt fits but just barely.