Alternator choice?

[Billy Nees]

Originally Posted by Robin Lawrence

Fuel injection loves Voltage. I also have 2 Optima Red Tops that have worked well. Most times after a run the batteries state of charge is at 95% unless I run the fan and water pump in the pits to cool down.

I think that you cannot go wrong by having too much capacity.

Good luck!

Robin

Ya know, a LONG time ago, I was playing with a FWD Pontiac Sunbird Turbo. PFI, tons of boost and OBD 1 but still an ECU. I couldn't feed that car enough juice to make it happy. I even had a local shop hop-up a big GM alternator for it. The supercharged Buick and the Cavalier (yes, even the Cavalier) that I play with want LOTS of amperage.
To be clear, what you're building probably won't need a lot of amperage to get it down the track if you have a large, fully charged battery in it. On my old 6 cylinder stuff I would shut off the alternator if I had to go fast but I also was turning off everything but the fuel pump and the ignition box.
You're better to have too much and not need it.