PULLEYS - hp increase vs low voltage?

Scott W

Founding Member
May 27, 2000
1,768
0
37
Toronto, Ontario
I've had u/d pulleys on my car for years now, and I loved them. the problem i'm having now is that i've added so many accessories to my car (2 amplifiers, nos heater, electric fan, msd6al,.......) that at idle, the voltage gauge drops right down.
My question is, could the pulleys also cost hp due to having a weak ignition system (especially in the lower rpm range?)
 
  • Sponsors (?)


WHo makes a 160 amp alt?

I find that the factory alts tend to make more power at lower RPM than aftermarket alts.

WIth my factory 95 GT alt and the ASP overdrive pulley, i could run my electric fan, my A/C , headlights and my stereo and not really have much of a drop. My car is AOD too so it doesn't rev at a stop like a 5-spd
 
Mustang5L5 said:
WHo makes a 160 amp alt?

I find that the factory alts tend to make more power at lower RPM than aftermarket alts.

WIth my factory 95 GT alt and the ASP overdrive pulley, i could run my electric fan, my A/C , headlights and my stereo and not really have much of a drop. My car is AOD too so it doesn't rev at a stop like a 5-spd

Heres the one I have. Expensive, yes but WELL worth it. I also have a mini high torque starter from him.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2476049674&category=33573&sspagename=STRK%3AMEBWN%3AIT&rd=1
 
I'm thinking an Optima battery could aid in the charge issue, but i agree that you can certainly lose power from your motor through a weakened ignition, especially if you've got an aftermarket ignition/coil/distributor and all that jazz.
 
i have a 130amp alternator and a pretty big stereo system. driving the car is fine, but at an idle it drops to like 1/4 maybe a little lower. it barely stays alive, but im fine with it. if/when the car ever stalls out those suckers are coming off.
 
Actually guys, I already have the asp overdrive alternator pulley, AND an optima yellow top battery! I did the math, the overdrive pulley brings the overall ratio to 2.5:1. the powermaster instructions specifically say not to use the u/drive pulleys, and that they are made to perform with an overall pulley ratio of 3:1. By the way, running u/d pulleys on the crank and alternator give you a ratio of 1.75:1. the overdrive alt. pulley certainly helped my situation, but with the latest addition of my electric fan the problem is as bad as ever.

After reading my msd 6al booklet, it says it can operate a full capacity with as little as 9volts.

I guess as far as the race track is considered, I end up revving well past 1200-1500rpm before launching - so everything should be operating properly when it really counts.

I'll just have to pay special attention if idling for lengthy periods of time.
 
I run a 130 AMP SN-95 alternator from Autozone. $109.00 Lifetime warranty. I also run an underdrive crank pulley (4 inch in the summer 3 inch in the winter) with the overdrive alternator pulley and it runs fine. With the 3 inch race pulley at idle it drops a little but with the 4 inch it runs fine. I set my idle between 850-900 RPM. I lso have a SN-95 Fan.

Oh by the way that part number from Summit is: ASP-520004

It's $18.50
 
I run a 95A alternator from Pa-Performance along with stock pulleys. I also have a dual 11" SPAL fully shrouded electric fan along with a/c. I use a Delta Controls electric fan controller which minimizes start up draw and steady state draw by varying the current to fan which provides for infinite speed control. Makes the fans MUCH LESS of a drag on the system. Better cooling performance than before (more stable), and much less wear and tear on the charging system. Never a problem with the voltage at idle, or with battery charging (rear mount battery). In many cases that electric fan controller will allow a smaller alternator to be used. www.dccontrol.com
 
cardudeusa said:
Those are part of the reasons I'm ditching my underdrives. IMO on a stock stang their a good buy. Once you add accessories and stuff forget about charging. I have a 160 amp 3G and at idle w/ the fan going and a/c on it doesnt charge.

hey if u decide to ditch the U/D's and they are in good shape. Hook me up with them, im looking for a set of U/D pulleys for my stang :nice: shoot me a PM if u decide to
 
Michael Yount said:
I run a 95A alternator from Pa-Performance along with stock pulleys. I also have a dual 11" SPAL fully shrouded electric fan along with a/c. I use a Delta Controls electric fan controller which minimizes start up draw and steady state draw by varying the current to fan which provides for infinite speed control. Makes the fans MUCH LESS of a drag on the system. Better cooling performance than before (more stable), and much less wear and tear on the charging system. Never a problem with the voltage at idle, or with battery charging (rear mount battery). In many cases that electric fan controller will allow a smaller alternator to be used. www.dccontrol.com

Do you have pictures of your set up? Their fan kits are expensive, but if I do end up buying a new fan I want the best money will buy. I'm sick of replacing cheap parts that don't work as good as I need. :nice: