quote:

Originally posted by Big Steve:

quote:

Originally posted by Dave Koehler:

quote:

Originally posted by Big Steve:
Many years ago my engine tossed the alternator belt during a bracket race and the car picked up .100 in the 1/8th.
If the vacuum pump is not pulling enough vacuum to increase HP, maybe by not driving it you will pick up some power like I did. Never know

Just curious.
Did you happen to prove that alternator out later with an ABA test?

No I took the alternator off the next race and the car stayed quicker that it normally was with the alt. Switched to a 16 volt battery shortly after and ran with a single battery without an alt for years

The reason I asked is that it should not have happened.
I suspect there was a bad diode in the alternator dragging it down. Been there.
It's pita to pin down when looking for a loss in engine power.
It is good that the race alternator MFGs spin them up before sending them out. In my case I was dealing with oem stuff.