Should I put alternator pulley back on?

Chris_H · 03-21-2001, 07:07 PM

Wed. is the tenative date for installing my Stewart water pump and my Black Magic electric fan. I have underdrive pullies on the car with the stock alternator. Should I go ahead and put my stock pulley back on, or do you think this 65(?)amp alternator with and underdrive on it will be enough to run the car, fan, and a/c? It doesn't dip down too low on the volts right now, but at night I can see my headlights dim at a stoplight. I just don't need a dead battery one day. Any suggestions are more than welcome.

Chris

------------------
1987 LX, rebuilt 306, Mac shorty headers 1 5/8, 2 1/2" Mac off road h-pipe, 2 1/2" 2 Chamber Flowmasters cat-back, Mac underdrive pullies, 3.55, K&N, Tremec 3550, King Cobra Clutch, Steeda Tri-Ax, Autometer gauges, White face gauges, blue silicone radiator hoses, Steeda Clutch Adjuster Kit.
Best times:
2.331 60ft, 9.966 @ 71.069 1/8 mile, 15.491 @ 91.846 1/4 mile at 4000 ft. elevation on street tires

dinomite · 03-21-2001, 07:11 PM

I don't think that that alt. will hold all that even if you put the stock pulley back on, cause the biggest part of the underdrives is the crank pulley. Even if you put all the stockers back on, it'd be a stretch methinks. Get a 3g/130 amp alt

dinomite · 03-21-2001, 07:14 PM

Man, I was just looking at your best times, elevation does crazy stuff! If you were to run it at sea level, I think you could be a second faster! Am I crazy guys? I didn't think elevation had that much of an effect........

92Rustang · 03-21-2001, 07:32 PM

If I had it to do again I would leave the alt. pulley stock. I done have any problems with my alt. with black magic and a pulley, but at night the volts get crazy low. I just tap the gas and kick the idle up to about 1100 and the alt charges fine.

------------------
Check my site for mod
www.fordmustanggt.com

MTU 50 · 03-21-2001, 07:37 PM

I have Underdrive pullies on my car and I am definitely going to change back to a stock sized pulley on the alternator.

It just isn't worth the small power gain of slowing the alternator to put up with charging problems.

My car doesn't charge at idle at all and there is noticable dimming of the headlights at night. At night with the lights on and say the heater going at full I am drawing a ton and there is a noticable lack of juice.

It is possibly the pullies of today are better than the ones I have. My Pullies were put on by the original owner back in 1994 I believe, and I have heard earlier pullies slowed the accessories down a little too much.

BTW-IGNORE the "March Pulley's" in my sig. I was going to get a nice set of those about a year ago, but didn't have the money. The pulley's I have are pieces of junk compared to March, which are very high quality IMO.

I'd better change that

------------------
1991 GT, AOD, Moroso Cold Air, 3.73s, March pulleys, 3-chamber(the left one fell off-NO time+No Money=College), FMS c-springs, and KYBs

Chris_H · 03-21-2001, 11:52 PM

Dinomite, between the elevation, the track, and my sorry excuse for tires, I can't get this car to move. Went to CA last summer for vacation and she ran like a wild woman. The elevation itself is worth about .76 or something of the sort. I have it written down, just can't recall off hand. The tires don't even think about hooking. Got a buddy running Mickey Thompsons with about 12psi and even he can't hook that well. Very poor track. But anyway, I think I will take my chances with the stock pulley. If that doesn't seem to hold, then I can use that as an excuse for the wife to let me get the alt. upgrade. Thanks for all the replys.

Chris

[This message has been edited by Chris_H (edited 03-21-2001).]

03-21-2001, 07:07 PM	#1
Chris_H Registered Member Join Date: Oct 1999 Location: New Mexico Posts: 488	Should I put alternator pulley back on? Wed. is the tenative date for installing my Stewart water pump and my Black Magic electric fan. I have underdrive pullies on the car with the stock alternator. Should I go ahead and put my stock pulley back on, or do you think this 65(?)amp alternator with and underdrive on it will be enough to run the car, fan, and a/c? It doesn't dip down too low on the volts right now, but at night I can see my headlights dim at a stoplight. I just don't need a dead battery one day. Any suggestions are more than welcome. Chris ------------------ 1987 LX, rebuilt 306, Mac shorty headers 1 5/8, 2 1/2" Mac off road h-pipe, 2 1/2" 2 Chamber Flowmasters cat-back, Mac underdrive pullies, 3.55, K&N, Tremec 3550, King Cobra Clutch, Steeda Tri-Ax, Autometer gauges, White face gauges, blue silicone radiator hoses, Steeda Clutch Adjuster Kit. Best times: 2.331 60ft, 9.966 @ 71.069 1/8 mile, 15.491 @ 91.846 1/4 mile at 4000 ft. elevation on street tires

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03-21-2001, 07:11 PM	#2
dinomite The Dude Join Date: Feb 2001 Location: Arlington, VA Posts: 1,262	I don't think that that alt. will hold all that even if you put the stock pulley back on, cause the biggest part of the underdrives is the crank pulley. Even if you put all the stockers back on, it'd be a stretch methinks. Get a 3g/130 amp alt

03-21-2001, 07:14 PM	#3
dinomite The Dude Join Date: Feb 2001 Location: Arlington, VA Posts: 1,262	Man, I was just looking at your best times, elevation does crazy stuff! If you were to run it at sea level, I think you could be a second faster! Am I crazy guys? I didn't think elevation had that much of an effect........

03-21-2001, 07:32 PM	#4
92Rustang Registered Member Join Date: Feb 1999 Location: Smithton, IL, US Posts: 215	If I had it to do again I would leave the alt. pulley stock. I done have any problems with my alt. with black magic and a pulley, but at night the volts get crazy low. I just tap the gas and kick the idle up to about 1100 and the alt charges fine. ------------------ Check my site for mod www.fordmustanggt.com

03-21-2001, 07:37 PM	#5
MTU 50 GOT TORQUE ???? Join Date: Aug 1999 Location: New Hudson, Michigan, USA Posts: 689	I have Underdrive pullies on my car and I am definitely going to change back to a stock sized pulley on the alternator. It just isn't worth the small power gain of slowing the alternator to put up with charging problems. My car doesn't charge at idle at all and there is noticable dimming of the headlights at night. At night with the lights on and say the heater going at full I am drawing a ton and there is a noticable lack of juice. It is possibly the pullies of today are better than the ones I have. My Pullies were put on by the original owner back in 1994 I believe, and I have heard earlier pullies slowed the accessories down a little too much. BTW-IGNORE the "March Pulley's" in my sig. I was going to get a nice set of those about a year ago, but didn't have the money. The pulley's I have are pieces of junk compared to March, which are very high quality IMO. I'd better change that ------------------ 1991 GT, AOD, Moroso Cold Air, 3.73s, March pulleys, 3-chamber(the left one fell off-NO time+No Money=College), FMS c-springs, and KYBs

03-21-2001, 11:52 PM	#6
Chris_H Registered Member Join Date: Oct 1999 Location: New Mexico Posts: 488	Dinomite, between the elevation, the track, and my sorry excuse for tires, I can't get this car to move. Went to CA last summer for vacation and she ran like a wild woman. The elevation itself is worth about .76 or something of the sort. I have it written down, just can't recall off hand. The tires don't even think about hooking. Got a buddy running Mickey Thompsons with about 12psi and even he can't hook that well. Very poor track. But anyway, I think I will take my chances with the stock pulley. If that doesn't seem to hold, then I can use that as an excuse for the wife to let me get the alt. upgrade. Thanks for all the replys. Chris [This message has been edited by Chris_H (edited 03-21-2001).]