It might work since you have 2 batteries. Even if 35 amps doesn't keep up with the electric pumps and fans it is still adding a charge back to the battery. If you have a voltmeter on the car you'll be able to see if you're losing charge during a race or staying even. If you want to be more scientific about it buy an inexpensive amp clamp gauge and check to see what is happening when the car is running and everything is on. Or install an ammeter into the system (can be tricky to do on a race car) and then you'll know if you are charging or discharging.
Sorry to be a pedant here but if the current demand is more than the alternator can output, you
will be drawing from the batteries. Sure the alternator will help as will the extra battery. For info on our car with a 105 amp powermaster alternator, we run electric w/p, dual fans, electric fuel pump, a small data logging system, gauges and a good ign system we are pulling close to 60 amps. I can't remember what the ampage breakdown was for each item though. It pulled another 35amps with all the lights on IIRC. It was one of the reasons why we re-wired it and changed most of the lamps to LED's. Haven't tried measuring total amps since but the logger says we maintain a constant 14.1 Volts making a pass. We also run a -ve wire ring in the car too.The Powermaster alt came with a "dyno" sheet, at 900rpm idle it put out 70A and by 1500 it was at max, 107A.
