Anybody running a 100amp alt on their race car?

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pettybludart

pettybludart

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Last race season my car was having a hard time starting after racing at night.I have a stock 1 wire alt(60amp) running an electric fuel pump,electric fan,electric waterpump drive.I notice my alt gauge drop when I also run headlights and tail-lights at night.I,m thinking about upgrading to a 100-amp alternater to help with the extra load while night racing.Do you think this will cure my issues?

Oh engine is a small block with eddy heads.
 
Are you running a stock mopar alternator and voltage regulator setup?

I use the powermaster 1 wire alternators....75 amp....

but we do not race with headlights on....as the track has lights...LOL
 
70aarcuda said:
Are you running a stock mopar alternator and voltage regulator setup?

I use the powermaster 1 wire alternators....75 amp....

but we do not race with headlights on....as the track has lights...LOL
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Yes a stock alt with a furd regulator.All our tracks have lights too(imagine that...Northern Lights LOL)At some of the tracks the return lanes and pits tend to be darker.Also at night we have to run with atleast 1 tail-light.:glasses7:Is your powermaster round or squareback,any interference with Eddy heads?
 
yes..the square back will hit the eddy heads......i spaced the alternator forward to clear the head.
 
When you say "stock one wire" that doesn't make sense. Do you mean a factory type so called "round back" with one field wire?

(A "one wire" is one with a built in regulator which has one total wire----the battery charging wire)

I don't know about aftermarket, but the older roundbacks do not put out so good at low / medium RPM. The factory "square back" are an improvement. Also, ultimate amps does not always tell the story. If you look at engineering curves for alternators----and they do exist, at least for Delco---- some LESSER rated output alternators put out MORE at lower / med RPM than some of the larger ones.

And as always---do some checks. Make sure your wiring is up to snuff. If you are running a trunk battery with a separate charging wire, no8 may not be large enough. Sure, it will charge, but it might not see full output.
 
70aarcuda said:
yes..the square back will hit the eddy heads......i spaced the alternator forward to clear the head.
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How did that work out with lining up with the crank pully?

Del I upgrade my complete wiring with a Ron Francis setup,maybe the stock 1 wire is just worn out.(old,used one)
 
67Dart273 said:
If you look at engineering curves for alternators----and they do exist, at least for Delco---- some LESSER rated output alternators put out MORE at lower / med RPM than some of the larger ones.

And as always---do some checks. Make sure your wiring is up to snuff. If you are running a trunk battery with a separate charging wire, no8 may not be large enough. Sure, it will charge, but it might not see full output.
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All of this!

Find an alternator that charges much higher rates at low rpm.
 
pettybludart said:
How did that work out with lining up with the crank pully?

Del I upgrade my complete wiring with a Ron Francis setup,maybe the stock 1 wire is just worn out.(old,used one)
Click to expand...

I use the alternators with the double pulley...line up the inside pulley with the crank...
 
I'll be using a Denso (91 Pathfinder I think). I already picked up the brackets from Mancini. Maybe this could be an option for you?
 
Revhendo said:
I'll be using a Denso (91 Pathfinder I think). I already picked up the brackets from Mancini. Maybe this could be an option for you?
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Thanks for the info. I,ll look into this option aswell.still a couple months before I can get the car out.:wack:
 
pettybludart said:
Thanks for the info. I,ll look into this option aswell.still a couple months before I can get the car out.:wack:
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There was a pretty decent thread on it a few years back on here. I used to have it bookmarked, but naturally, I can't find it right now......
 
Revhendo said:
I'll be using a Denso (91 Pathfinder I think). I already picked up the brackets from Mancini. Maybe this could be an option for you?
Click to expand...

Same deal except I used a 85amp denso off a Camry. Changed the pulley and made these brackets



 
Nice handy work there Rob.I could also probably rig something up,but looking to hopefully just bolt and go.I,ll figure something out...so many options.Thanks for pics.
 
How much initial advance are you running??? You may need an MSD box that drops 20 degrees at start.
 
I run a 90-110 amp denso from a 88 or 89 dodge truck, on my slant six. The only wiring I changed was adding a 8 gauge direct from the alt to the battery. On a slant six you only need to cut a 1/4 inch off the front of the cast alternator mount, and everything lines uo.
I have two electric fuel pumps, Electric fan and water pump, MSD, nitrous bottle heater, nitrous solenoids, plus I run headlights coming back to the pits. I also installed a normally closed relay in the in the field circuit of the alternator, that is triggered by the full throttle micro sw. The switch turns on the nitrous, and shuts off the alternator, any time the throttle is wide open, but allows normal charging at any other time.

The only time I have a problem, is if I get running my mouth, and forget to turn off the fan and water pump, after the engine has cooled.
 
figuring out of an alternator is a delta or a "Y" junction armature may be handy. the 100A chrysler units are a delta junction, high ouput lower rpms, the squarebacks are high output mid-high rpms. im pretty sure the nippy units are a "Y" junction as well. Bypassing the ammeter by removing the red wire from the ammeter to the starter relay, and retaining the original black charge wire only from the alternator to the junction that feeds the fuse box/ignition switch as a power feed only, and running new 4 GA. from the alternator, through a manual reset 80A circuit breaker (this is where the original charge wire/now power feed ties in), to the starter relay 5/16 post, then to the battery has solved all my issues related to situations like yours. in both my powerwagon and my dart. I run 60a squarebacks in both.
 
66durgederp said:
.......... delta or a "Y" junction armature......... I run 60a squarebacks in both.
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I don't think it's that simple. There are smaller rated squarebacks that put out MORE at lower RPM than the 60-65A units.............BUT...............

In this day and age where we have the awful quality of hammer/ slam / rebuilts, it's doubtful that what started as a 60A, a 55A, or whatever, now retains it's original armature, and certainly not stator. What I mean is, what was original, no longer is.

(What happens, example, if a rebuilder stuffs an older, roundback stator into what was a nice squareback?)

Seems to me that "newer is better" so far as output performance, although my car, which has no special needs other than EFI, still runs an everyday squareback.
 
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