Running an alternator

[Eman]

Originally Posted by Robbie Welch

Thanks again for the response's. My concern is load on the alternator possibly changing during a run and the affect it would have (if any) on the run.

The load from an alternator occurs when there is a need for it. If you cool the car after a run without charging you are drawing from the battery. Then when you start the car and make a pass the alt is working to replenish what you drew out of the battery while cooling and to keep up with any draw while running. Better to charge while cooling and the load of the alt will be less and consistent.

[Robbie Welch]

Thanks again for all the response's. I was thinking of putting a RPM switch to trigger a relay in the alternator output to kill it during the run. I think when I get a chance I do a A-B-A test taking the belt off to see if there's anything to it. Thanks again

[Ed Wright]

Robbie, I first put a universal starter button under my gas pedal, wired to a relay so it went open (off) when pressed. At WOT it opened the wire to the alternator. Worked fine.

[Coleydog]

Why even put an alternator on if you're not going to use It during the run? All the power drain occurs then. The only purpose of the battery, after installing an alternator, is to start the engine. The alt supplies ALL the voltage your componites require (at 14 volts not 12 or less), that extra voltage more than makes up for any HP loss that MIGHT occur.

[Ed Wright]

Mine ran faster with it turned off during the run.
Even a little quicker with two 16 volt batteries, and no alternator.
Your results might vary. Don't know if you don't test.

[Mark Yacavone]

I do it for consistency, not necessarily ET.
On my 2300 turbo, you could hear the idle pull down when you switched on the alternator.

The Monte has never had the alternator switched off. Not even on record passes.
It dials pretty well, and follows along with the big boys' ET's.
Of course, it has the stock computer (which Ed re-did for us), and also stock ignition.
Plus the trans doesn't use any juice either.
So, who knows, without a-b-a testing within a reasonable time frame?

[MR DERBY CITY]

The only advice I can give you is.....when they start hot lapping your AZZ, you will be a very happy racer IF you have a very Functional charging system. ........

[Ed Wright]

Originally Posted by MR DERBY CITY

The only advice I can give you is.....when they start hot lapping your AZZ, you will be a very happy racer IF you have a very Functional charging system. ........

I have no problem making three "hot laps" with two 16 volts.

[Mike Pearson]

Originally Posted by MR DERBY CITY

The only advice I can give you is.....when they start hot lapping your AZZ, you will be a very happy racer IF you have a very Functional charging system. ........

I don't run an alternator. I have a 16 V battery. I ran 11 rounds at one of our Southern Stock Super Stock Assn races last year in one afternoon. 2 rounds of qualifying won the first race and lost 2nd round in the 2nd race. Battery was charged between rounds and I cool off with a separate battery.

[MR DERBY CITY]

Ed, my experience is limited to STOCK Eliminator with ONE 12 volt battery....I will HOT LAP with the best of them because......my charging system is top notch ....Remember , when you are hot lapping there is no time to visit the trailer and charge the battery....