Auto Racing: alt.effects on H.P., vacuum switch, sarasota florida

Question
How much horsepower is lost by running an alternator for stock car racing, better to take alt. off and charge battery fully before running it in each racing stage?

Answer
Hi Jeff:

Only 2 or 3 horsepower, but every last one counts. I race in three classes, in one of them I have to have a working alternator on the car.  I've rigged a vacuum switch so that when I'm on the gas, the alternator is disconnected. The only time it charges is at idle or if I'm off the gas, downshifting and entering a corner.

The other two cars are not equipped with alternators for that reason. Besides, they're extra weight !!

Dan Liddy
Sarasota, Florida