Alternator choice?

[Rory McNeil]

Like Paul, I have found the factory equipment alternator more than adequate. On my 85 Mustang Stocker, as well as my 78 Fairmont bracket car, I used the factory alternator and external voltage regulator, Ford offered them in several different output ratings, I think the alternator that has been in my Fairmont for almost 40 years, is less than 50 amps. That said, I am also using a full sized conventional battery, with 500-600 CCA. My cars have much of the typical drag car stuff, like an electric water pump, electric fan, electric fuel pump (s), and a MSD ignition, although I run 6 series boxes, I believe the 7 series boxes take a fair bit more current to operate. Over the years, I have found that as long as I had the battery fully charged before the race weekend, with the full size battery and alternator, I can usually go thru a 2 or 3 day race weekend without having to fire up the generator and charging the battery between rounds. About the only time that I charge the battery, is if I am in a "hot lap" situation during later rounds, especially on a hot day, so that I have to run the fan and water pump a lot. Obviously, if your alternator is non functional, that wouldn`t work.

[Eman]

How much amperage do you think you need? What gauge wire are you running from the alternator that can carry the amperage?

[cad]

Ive spoken with Tuff Stuff Performance. Their CS130 alternator is exactly the same one that is re-sold by hop. They can be purchased from summit. I have had both, and currently running the Tuff Stuff branded alternator. 7500rpm and it puts out 14.1v at 1000 rpm...
I do use hop's starter which is fantastic.

[CMcAllister]

Nice stuff? Paynes

Budget? Delcotron with a one wire kit. You can carry parts for it - diode trio and rectifier - and fix it at the track if it breaks.

[Robin Lawrence]

You didn't clarify your estimated amp draw on your car. I had a conversation with Larry Hill about this very subject late last year.

If you're running a carburetor with a stock type coil you can get away with a lot less.

I run an EFI system that uses wide band 02 sensors in each primary for data and 2 more in the collectors for the EFI system. Add a EFI High Pressure fuel pump, Large Cooling Fan, electric water pump, 2 Digital Dashes and a Race Pak the little items add way up.

Last car we logged years ago didn't have the Race Pak, 02's on primaries or digital dashes. I was drawing 60 to 65 amps during a chassis dyno run.

Since I was at Holley when I built this car I opted for the MSD 5361 160 amp alternator.

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

[Jeff Niceswanger]

Originally Posted by Robin Lawrence

You didn't clarify your estimated amp draw on your car. I had a conversation with Larry Hill about this very subject late last year.

If you're running a carburetor with a stock type coil you can get away with a lot less.

I run an EFI system that uses wide band 02 sensors in each primary for data and 2 more in the collectors for the EFI system. Add a EFI High Pressure fuel pump, Large Cooling Fan, electric water pump, 2 Digital Dashes and a Race Pak the little items add way up.

Last car we logged years ago didn't have the Race Pak, 02's on primaries or digital dashes. I was drawing 60 to 65 amps during a chassis dyno run.

Since I was at Holley when I built this car I opted for the MSD 5361 160 amp alternator.

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

Last summer while on the dyno (down at Gales) we had an unexpected 10 HP drop out of nowhere. Looking at comparison data it looked identical.... except Tony had forgot to turn the charger back on in the dyno room. The voltage had fallen to 11.5 volts during the pull. This was an L-98. That dyno room has a 7AL2 for ignition juice. Turned the charger back on and we instantly was back to normal power levels.

[goinbroke2]

Thanks for the replies everyone. I am running 6AL and a holley fuel pump as well as dual fans off of something from the junkyard (charger I think?) The waterpump drive is being replaced with an electric water pump. Oh yeah, the big killer, power windows up and down a dozen times trying to keep cool, lol!

Total amp draw? Don't know but I'm always thinking "rather too much and not need it than need it and not have it." (paraphrasing Sun Tzu, lol)

Go for eye surgery Monday AM so everything will be on hold for a bit, pull the trigger when I can...or stay with stock alternator with a new belt.....hmmmm....

[Alan Roehrich]

Originally Posted by Robin Lawrence

You didn't clarify your estimated amp draw on your car. I had a conversation with Larry Hill about this very subject late last year.

If you're running a carburetor with a stock type coil you can get away with a lot less.

I run an EFI system that uses wide band 02 sensors in each primary for data and 2 more in the collectors for the EFI system. Add a EFI High Pressure fuel pump, Large Cooling Fan, electric water pump, 2 Digital Dashes and a Race Pak the little items add way up.

Last car we logged years ago didn't have the Race Pak, 02's on primaries or digital dashes. I was drawing 60 to 65 amps during a chassis dyno run.

Since I was at Holley when I built this car I opted for the MSD 5361 160 amp alternator.

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

Race engines run on gasoline, most of the time. Race CARS run on electricity.

[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.