16 volt system with alternator.

[LS1Racer]

I wanted to get some input on a 16 volt system with alternator. Late model F body stocker with 16 volt batteries and powermaster XS alternator. I also have a voltage step down box 25 amp continuous. My question is if the components will handle the 18.6 volts while charging. I realize the gauge lights and small things will need to be stepped down but what about the injectors, starter, Fast XFI ECU, MSD7AL,e shift and valve body,etc.I have heard those components will have no issue at 16v but not sure with the added charging volts Thanks in advance for any help.

[jamie2370]

Save yourself the trouble and please shut off the master switch when charging the batteries. If the charger spikes, it will take out all kinds of stuff

[jamie2370]

the alternator should not charge voltage that high. If it does check to see if it is adjustable. Anything over 18 will likely spike a Fast ecu driver

[Robin Lawrence]

Originally Posted by jamie2370

Save yourself the trouble and please shut off the master switch when charging the batteries. If the charger spikes, it will take out all kinds of stuff

This is what we have seen cause issues. the charger is at 20+ volts and when the starter turns over it can send voltage spikes into the ECU.
Turning off the charger while cranking solves this.

Some smart coils (IG1A) have issues over 17 volts. They can shut off. Most of the GM smart coils are ok.

Robin

[LS1Racer]

Originally Posted by jamie2370

the alternator should not charge voltage that high. If it does check to see if it is adjustable. Anything over 18 will likely spike a Fast ecu driver

That voltage is what I have read online. Alternator is adjustable from 13.5 to 18.6. My thoughts were to set to 16 volts and charge between rounds with switch off. I figured anything much above 16v would start frying things. Manufacturer of Electric fan (Deraile) states it will burn up at 16v.

[bykr]

Originally Posted by LS1Racer

That voltage is what I have read online. Alternator is adjustable from 13.5 to 18.6. My thoughts were to set to 16 volts and charge between rounds with switch off. I figured anything much above 16v would start frying things. Manufacturer of Electric fan (Deraile) states it will burn up at 16v.

I always start charging while cooling the engine using the water pump and an electric fan and have never had an issue for years. If fans fried at 16v no one would be running one with a 16v system as normal full charge voltage is almost 17v.

[LS1Racer]

Originally Posted by bykr

I always start charging while cooling the engine using the water pump and an electric fan and have never had an issue for years. If fans fried at 16v no one would be running one with a 16v system as normal full charge voltage is almost 17v.

I realize that point. My main question was at what point of voltage would you be concerned about component damage running with an alternator to charge the batteries.

[countrypuppy4865]

You shouldn’t have any issues mine charges at 18 with the powermaster adjustable alternators and really don’t need to charge it. I would suggest checking your alternator rpm you may want a larger pulley to prevent it from spinning too fast. Since it is adjustable if you would prefer to lower the setting to around 17.2-17.5. However, under a load it won’t be that high.

[LS1Racer]

Originally Posted by countrypuppy4865

You shouldn’t have any issues mine charges at 18 with the powermaster adjustable alternators and really don’t need to charge it. I would suggest checking your alternator rpm you may want a larger pulley to prevent it from spinning too fast. Since it is adjustable if you would prefer to lower the setting to around 17.2-17.5. However, under a load it won’t be that high.

Thanks for that info, that is what I was hoping to find out. I did put the larger pulley on to slow it down. Thanks again for the help.

[Mike Mans]

Like the Puppy said, the Powermaster alternators can work so well that we rarely ever put a charger on the car anymore. With dual 16v batteries the system all runs very well.

What class are you going to be running with your Firebird LS1Racer? Always like seeing more of these cars in Stock, hopefully things are going well for you!

Mike