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Author Topic:   Alternator
extreme
Member
posted November 27, 2000 07:27 AM
A friend of ours recommends that we run an alternator in our Modified. He runs one on his and thinks it's well worth it, even though we may lose 5% or less horsepower and add a little weight. I'd like to hear what you all think on the subject. Thanks!


dirtrackracer
Member
posted November 27, 2000 04:31 PM
Like you, I kicked this question around quite a bit also. Granted, alternators will keep the battery system at full capacity,I hated the idea of hanging another belt off the crank. So, after a few well placed phone calls, I ended up with the following.

I run a HEI distributor from DUI. Its a 1 wire unit. I then purchased an Optima battery at the cost of $165 from HOWE. HOWE swears these batteries will run 200 laps with very minimal voltage loss. I also use the glow in the dark type gauges (no lights needed). I know of several others with the same type ignition and battery and they have absolutely no power loss. The battery will crank the engine easily after 100 lap features. Give HOWE a call at 517-435-7080.

The battery weighs 39 pounds and can be mounted in any position and is zero maintainence. Hope this helps.

Hammer 1
Member
posted November 27, 2000 10:04 PM
I agree with limited 5. For the length of the races most of us run,it is another added cost item to break, quit, fall off or otherwise get in the way. My motor builder played around with an MSD system on the dyno and found out that voltage drop wouldn't become a problem until around 100 laps. Could be a problem for a late model but even the longest modified race in this area is 50 laps. Well within that 100 lap window. Our system is total MSD. We pack the trickle charger and throw it on after our heats and let it charge while the other divisions qualify. Haven't had any problems yet.


saintmike
Member
posted November 29, 2000 01:00 PM
My experience: Not worth it! Froze up the bearings on two ocasions, even with the bigger pulleys. Still can't get over one night, running in front and overheating because the alternator locked-up, smoked the belt and finnaly wrapped itself around the fan and waterpump pulley. Didn't feel like wrecking the motor. Also, the added weight, maintennce, and expense. IMHO.


garyg1
Member
posted November 29, 2000 07:02 PM
I have run a HEI with just a plain walmart battery for the last 5 years. never a problem. ran 83 laps because of yellow flags on a 35 lap feature race one night and won the race going away at the end. Car started fine from victory lane. I run lights in my gauges, still no problem. Buy the better battery Limited5 listed above and you have all the insurance you need to run a 200 lap race i am sure. Have no experience with the MSD so don't know about tht deal and battery power loss.


Merly
Member
posted November 30, 2000 09:03 AM
I run a GRT mod with a Ford 302 , I sat on the pole for the CMT mod race At Lowes Dirt track in Sept this year.
Here is what I run : I use a 3 lb 45 amp alternator along with a 23 lb battery ,total weight of components is 26 lbs , that is 13 lbs lighter than the battery the other guy uses.Also you have an unlimited/endless supply of electricity , you don't need to carry a battery charger to the race track with you and you will never have to worry about running out of juice wether you run a 20 lap race or a 500 lap race .And as for horse power loss ... a 140 amp alternator charging an all out MSD box ,coil ,dist, battery and full set of gauges uses 1/3 of a hp at 7200 rpm . I know for fact because I've dynoed it myself back to back with no alt at all. The alt set-up I use on my car was supplied a guy who does starters and alternators for Winston Cup ,Busch ,Hav-A-Tampa ,UMP Mods , IMCA mods ,and local oval races in all classes. He will let you know everything you need to know about running a charging system .His name is Phil call him at 704-435-2934.
I my opinion , if you are running a high end ignition system ,wether it is MSD or HEI or any other combination ,and are looking for a virtually maintenance free system , an alternator is the only way to go. The people that say they aren't any good most likely have never even run a racing alt setup.


Merly


dirtrackracer
Member
posted November 30, 2000 05:08 PM
so extreme, what have conclusions have you come up with after reading all this?

------------------
RACERX


garyg1
Member
posted December 01, 2000 07:00 PM
agree that a good alternator system is trouble free. but back to the point when it is not needed why spend any money or excess weight on the car when it is not needed at all. just something else that might go wrong, extra bolt ons everytime you change the motor and extra belts to tension properly. I throw a charger on my battery for maximum of 15 minutes before I leave for the races on Saturday afternoon and never touch it all night. never a battery problem in 5 years of modified racing. one fellow racer who is really lazy bragged about not charging his for over two months. always started. I'm not that brave. the battery on my electric hoist on my trailer sees lots more punishment than the race car battery and I never have to charge it but twice a year. for weekend only warriors it is just not needed.


Limited5
Member
posted December 02, 2000 07:58 PM
Lets see,10 hot laps,8 lap heat,20 to 30 lap feature, thats 48 to 50 laps max. If you need an alternator for 50 laps you got problems!


Hammer 1
Member
posted December 03, 2000 10:32 AM
Amen Limited 5. A high profile motor builder in this area went on a kick a few seasons ago wanting all his pure stock and semi-late guys to run a one wire alternator . Many of them shelled out the big bucks for the brand name unit (which he sold.) I went to the big race flea market at Silver Springs a few weeks ago and you wouldn't believe the one wire alternators for sale for a song. And the whole time I walked around I didn't see one guy buying or carrying an alternator. That tells me something.


PEDDLER
Member
posted December 03, 2000 07:33 PM
If you run a stock or partially modified G.M. hei dist, an altenator is your best bet. We ran a stock 63 amp Chev. pick up alt for years with no trouble. Used a big pulley and made our own 1 wire unit.
A HEI runs best at 13.8 to 14.2 volts. You can get buy not running one if you have an aftermarket ignition (unilite etc. with a box).


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