Underdrive performance W/O alt. pulley.

Shotgun28 · 01-26-2001, 05:51 PM

With my new ASp underdrive pulleys I was told they run prety hot, and was wondering, what is the performance difference not using the Alt. pulley and just using the other two.
I still have the stock alternator and was just trying to get some views, I will eventually get a new powdercoated PA alternator, but for now I am stuck with the stocker.

------------------
91 LX Convertible Gray on Red B&M Shift improver kit,ASP red alum. underdrive pulleys, Richmond 3.73 gears, 1 5/8 Flowtech long tube Headers and off road h-pipe, Flowmaster 2-chamber cat-back with S.S exhaust, MSD 6A Ignition with coil,Cap and rotor, Taylor Pro wires, K&N 12" conical filter system, Jet stage 2 performance chip and just purchased some GT40P heads, looking at exhaust, Lentech Street Terminator plus on it's way...

cw50must · 01-27-2001, 10:06 AM

I only run the two pulleis and to tell you the truth I don't see any difference than with all three (performance wise) You still will pick up a bit with only two and won't have the charging problems. Some people say you have to have all three to get the gains, but there is definately a gain with only two.

------------------
1991 GT 5.0L 5spd
Mesa, AZ
visit cw50must's web site

NOS_Notch · 01-27-2001, 02:17 PM

Actually i've always heard that the performance gain is all in the crank pulley.
The other two are for belt sizing....

------------------
4.10's,long tubes & 75 shot...Goes 12.50's
Check it out at http://www.burnouts.webprovider.com

Phil Ossifer · 01-27-2001, 02:27 PM

Shotgun28,

I used to run all three pullies, got tired of dead battery syndrome...

Re-installed the stock alternator pully, no more charging problems; can't tell any difference in performance either. Probabably could tell at the track but I don't race it.

Phil

93SVTstang · 01-27-2001, 08:18 PM

I ran it with just the 2 pulleys for a while, then switched the alternator for the bigger one and haven't noticed any performance difference or charging difference for that matter.

NO SLO PK · 01-27-2001, 10:36 PM

Agreed, the difference in power with the stock vs. underdrive alternator pulley is negligible, in my opinion. I kinda doubt you'd see much of a diff. on a dyno. I've run with two pullies, but I think I had to use a shorter belt.

------------------
'91 LX
Procharger, 3 row intercooler, extrude honed Cobra intake, Mac full Length Headers, 30# inj., 73mm C&L, 75mm tb, E303 cam, 289 rods, ported E7 heads, MSD, T-Rex w/255 lph Walbro, 5 lug conversion, Cobra R wheels, 3.27 gears and Moser Axles.

redsn95vert · 01-29-2001, 11:55 AM

I run all three pullies with stock alt. And only notice slight difference with the charge when at stoplights at night with lights, signal, And my sterio full blast. The gague never goes below the N in normal.

------------------
95 GT convertable, 3.73 gears, bbk off road h-pipe, march underdrive pullies, Saleen wires, custom made cold air induction,
Future mods (Winter/Spring break)
Cobra intake w/ 65mm tb
GT40 heads, flowtech headers, Lunatti cam 230 duration 488 lift

95mustanggt · 01-29-2001, 01:12 PM

Do the 94/95 GT's have a larger alternator?

------------------
White 1995 Mustang GT
Dynomax Cat-Back, Offroad H-pipe, K&N Filters w/o Air Silencer
My 1995 Mustang GT

redsn95vert · 01-31-2001, 11:46 AM

I'm not sure but I think they did bump up the juice a little bit. My headlights do dim a little at idle but as soon as I give it gas I'm fine, and have never had any problems.

------------------
95 GT convertable, 3.73 gears, bbk off road h-pipe, march underdrive pullies, Saleen wires, custom made cold air induction,
Future mods (Winter/Spring break)
Cobra intake w/ 65mm tb
GT40 heads, flowtech headers, Lunatti cam 230 duration 488 lift

01-31-2001, 12:54 PM

95mustanggt: When I asked an alternator-related question a month or two back I was told the SN-95 cars did indeed come with a better alt that could be used in a Fox car with minimal trouble.

Wanna sell yours?

------------------
Greg
91 LX Convertible

95mustanggt · 01-31-2001, 05:10 PM

Nope

, there is a guy in town who is selling MAC underdrives for $110 Canadian. I think I'll grab a set for my birthday in the spring

.

I was concerned about some problems, but I heard that the 94/95 GT's had a larger alternator. I could use the power gain.

------------------
White 1995 Mustang GT
Dynomax Cat-Back, Offroad H-pipe, K&N Filters w/o Air Silencer
My 1995 Mustang GT

IMPULSERACING · 01-31-2001, 05:51 PM

The SN95 came with a 130 amp alternator. Many racers put them on there fox's to increase the out put. I just ordered one. Two guys in my club already run them. You just have to modifiy the bracket slightly to make it fit. Hope this helps.

------------------
92' LX Hatch 5 spd Edelbrock Performer Intake, pro-m 75mm MAF, 70mm T.B., 24lb injectors, 190lph, Mac fenderwall cold air induction, mallary ignition and coil, Cobra 1.7 rockers, 373:1 gear, upper and lower control arms, supersubs, 50/50's, front drag springs, no sway bar, battery in hatch, compucar N20 kit
13.42 @ 100.50 N/A on radials
No time on Juice yet

95mustanggt · 01-31-2001, 06:26 PM

So I should have no problem putting on those under drives

StreetStang37 · 01-31-2001, 11:44 PM

I think the alternator pulley gives you 2 hp, maybe 3.5 hp max.

With my music at full blast (2 amps, subs) my meter goes down to the line before the last one when the bass hits, so I don't play it much.

------------------
1993 Mustang GT - March Ram Air, K & N filter charger, Pullies, Super Competition Hooker Headers, 2 1/2 in. mendrel bent cat back, High Flow H-Pipe, Pro 5.0 Power Tower

90dpscoupe · 02-03-2001, 02:14 AM

Needed to bring this topic back up, i talked to a guy at a performance shop, and he said "not using the altrntr pulley can undercharge more? the crank pulley slows everything down, so the underdrive water pump and alternator pully have a different ratio to speed up the accesories?

Im confusing myself now, but the underdrive crank turns accesories slower, but the different ratio on WP and alternator makes up for it by spinning them faster?

joe4speed · 02-03-2001, 06:08 AM

I have converted to the 130 amp alternator, and easy job and well worth it, especially if you're running pullies. just cut a notch in the bracket with a dremel and splice in a couple wires, and thats it! I recommend upgrading if you have a wimpy alternator!

------------------
Joe!
1988 GT, 167,000 miles!!! 13.71@105mph Check out my listing! Click here! Or my website:
www.joe4speed.com
1999 Ninja ZX-6R 10.32@135mph!

John · 02-04-2001, 11:24 AM

i have the asp's and have no probs charging on a discount autoparts alt, it actually came w/ same size pulley as the asp pulley, also my car does not overheat in any weather conditions 2 summers here in SW Florida, barely makes it to first line on the gauge w/ stock waterpump and thermo. John

------------------
89 Notch: ASP Pullies, K&N Air,Transgo shiftkit,Trany cooler,FMS 3 core Radiator, FMS 4:10's

01-26-2001, 05:51 PM	#1
Shotgun28 Registered Member Join Date: Sep 2000 Location: New Hope MN USA Posts: 276	Underdrive performance W/O alt. pulley. With my new ASp underdrive pulleys I was told they run prety hot, and was wondering, what is the performance difference not using the Alt. pulley and just using the other two. I still have the stock alternator and was just trying to get some views, I will eventually get a new powdercoated PA alternator, but for now I am stuck with the stocker. ------------------ 91 LX Convertible Gray on Red B&M Shift improver kit,ASP red alum. underdrive pulleys, Richmond 3.73 gears, 1 5/8 Flowtech long tube Headers and off road h-pipe, Flowmaster 2-chamber cat-back with S.S exhaust, MSD 6A Ignition with coil,Cap and rotor, Taylor Pro wires, K&N 12" conical filter system, Jet stage 2 performance chip and just purchased some GT40P heads, looking at exhaust, Lentech Street Terminator plus on it's way...

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01-27-2001, 10:06 AM	#2
cw50must Registered Member Join Date: Dec 1999 Location: Mesa, AZ, USA Posts: 91	I only run the two pulleis and to tell you the truth I don't see any difference than with all three (performance wise) You still will pick up a bit with only two and won't have the charging problems. Some people say you have to have all three to get the gains, but there is definately a gain with only two. ------------------ 1991 GT *5.0L* 5spd Mesa, AZ visit cw50must's web site

01-27-2001, 02:17 PM	#3
NOS_Notch Registered Member Join Date: Sep 2000 Location: Fresno,CA. USA Posts: 384	Actually i've always heard that the performance gain is all in the crank pulley. The other two are for belt sizing.... ------------------ 4.10's,long tubes & 75 shot...Goes 12.50's Check it out at http://www.burnouts.webprovider.com

01-27-2001, 02:27 PM	#4
Phil Ossifer Registered Member Join Date: Jan 1999 Location: Sterling Heights, Michigan Posts: 217	Shotgun28, I used to run all three pullies, got tired of dead battery syndrome... Re-installed the stock alternator pully, no more charging problems; can't tell any difference in performance either. Probabably could tell at the track but I don't race it. Phil

01-27-2001, 08:18 PM	#5
93SVTstang Registered Member Join Date: Dec 2000 Location: Metairie, LA, United States Posts: 80	I ran it with just the 2 pulleys for a while, then switched the alternator for the bigger one and haven't noticed any performance difference or charging difference for that matter.

01-27-2001, 10:36 PM	#6
NO SLO PK Registered Member Join Date: Mar 1999 Location: Arcadia, CA, USA Posts: 731	Agreed, the difference in power with the stock vs. underdrive alternator pulley is negligible, in my opinion. I kinda doubt you'd see much of a diff. on a dyno. I've run with two pullies, but I think I had to use a shorter belt. ------------------ '91 LX Procharger, 3 row intercooler, extrude honed Cobra intake, Mac full Length Headers, 30# inj., 73mm C&L, 75mm tb, E303 cam, 289 rods, ported E7 heads, MSD, T-Rex w/255 lph Walbro, 5 lug conversion, Cobra R wheels, 3.27 gears and Moser Axles.

01-29-2001, 11:55 AM	#7
redsn95vert Registered Member Join Date: Jul 2000 Location: Rochester Posts: 323	I run all three pullies with stock alt. And only notice slight difference with the charge when at stoplights at night with lights, signal, And my sterio full blast. The gague never goes below the N in normal. ------------------ 95 GT convertable, 3.73 gears, bbk off road h-pipe, march underdrive pullies, Saleen wires, custom made cold air induction, Future mods (Winter/Spring break) Cobra intake w/ 65mm tb GT40 heads, flowtech headers, Lunatti cam 230 duration 488 lift

01-29-2001, 01:12 PM	#8
95mustanggt Registered Member Join Date: May 2000 Location: Kamloops, BC Posts: 2,875	Do the 94/95 GT's have a larger alternator? ------------------ White 1995 Mustang GT Dynomax Cat-Back, Offroad H-pipe, K&N Filters w/o Air Silencer My 1995 Mustang GT

01-31-2001, 11:46 AM	#9
redsn95vert Registered Member Join Date: Jul 2000 Location: Rochester Posts: 323	I'm not sure but I think they did bump up the juice a little bit. My headlights do dim a little at idle but as soon as I give it gas I'm fine, and have never had any problems. ------------------ 95 GT convertable, 3.73 gears, bbk off road h-pipe, march underdrive pullies, Saleen wires, custom made cold air induction, Future mods (Winter/Spring break) Cobra intake w/ 65mm tb GT40 heads, flowtech headers, Lunatti cam 230 duration 488 lift

01-31-2001, 12:54 PM	#10
cleangreenmachine Guest Posts: n/a	95mustanggt: When I asked an alternator-related question a month or two back I was told the SN-95 cars did indeed come with a better alt that could be used in a Fox car with minimal trouble. Wanna sell yours? ------------------ Greg 91 LX Convertible

01-31-2001, 05:10 PM	#11
95mustanggt Registered Member Join Date: May 2000 Location: Kamloops, BC Posts: 2,875	Nope , there is a guy in town who is selling MAC underdrives for $110 Canadian. I think I'll grab a set for my birthday in the spring . I was concerned about some problems, but I heard that the 94/95 GT's had a larger alternator. I could use the power gain. ------------------ White 1995 Mustang GT Dynomax Cat-Back, Offroad H-pipe, K&N Filters w/o Air Silencer My 1995 Mustang GT

01-31-2001, 05:51 PM	#12
IMPULSERACING Registered Member Join Date: Dec 1999 Location: chicago,IL,USA Posts: 158	The SN95 came with a 130 amp alternator. Many racers put them on there fox's to increase the out put. I just ordered one. Two guys in my club already run them. You just have to modifiy the bracket slightly to make it fit. Hope this helps. ------------------ 92' LX Hatch 5 spd Edelbrock Performer Intake, pro-m 75mm MAF, 70mm T.B., 24lb injectors, 190lph, Mac fenderwall cold air induction, mallary ignition and coil, Cobra 1.7 rockers, 373:1 gear, upper and lower control arms, supersubs, 50/50's, front drag springs, no sway bar, battery in hatch, compucar N20 kit 13.42 @ 100.50 N/A on radials No time on Juice yet

01-31-2001, 06:26 PM	#13
95mustanggt Registered Member Join Date: May 2000 Location: Kamloops, BC Posts: 2,875	So I should have no problem putting on those under drives

01-31-2001, 11:44 PM	#14
StreetStang37 Registered Member Join Date: Dec 2000 Location: San Jose, California USA Posts: 275	I think the alternator pulley gives you 2 hp, maybe 3.5 hp max. With my music at full blast (2 amps, subs) my meter goes down to the line before the last one when the bass hits, so I don't play it much. ------------------ 1993 Mustang GT - March Ram Air, K & N filter charger, Pullies, Super Competition Hooker Headers, 2 1/2 in. mendrel bent cat back, High Flow H-Pipe, Pro 5.0 Power Tower

02-03-2001, 02:14 AM	#15
90dpscoupe Registered Member Join Date: Jun 2000 Location: sanantonio, Tx, usa Posts: 1,407	Needed to bring this topic back up, i talked to a guy at a performance shop, and he said "not using the altrntr pulley can undercharge more? the crank pulley slows everything down, so the underdrive water pump and alternator pully have a different ratio to speed up the accesories? Im confusing myself now, but the underdrive crank turns accesories slower, but the different ratio on WP and alternator makes up for it by spinning them faster?

02-03-2001, 06:08 AM	#16
joe4speed He said Member...heh, heh Join Date: Sep 1999 Location: Jupiter, Florida U.S.A. Posts: 3,718	I have converted to the 130 amp alternator, and easy job and well worth it, especially if you're running pullies. just cut a notch in the bracket with a dremel and splice in a couple wires, and thats it! I recommend upgrading if you have a wimpy alternator! ------------------ Joe! 1988 GT, 167,000 miles!!! 13.71@105mph Check out my listing! Click here! Or my website: www.joe4speed.com 1999 Ninja ZX-6R 10.32@135mph!

02-04-2001, 11:24 AM	#17
John Registered Member Join Date: Dec 1998 Location: Ft.Myers, FL. Posts: 150	i have the asp's and have no probs charging on a discount autoparts alt, it actually came w/ same size pulley as the asp pulley, also my car does not overheat in any weather conditions 2 summers here in SW Florida, barely makes it to first line on the gauge w/ stock waterpump and thermo. John ------------------ 89 Notch: ASP Pullies, K&N Air,Transgo shiftkit,Trany cooler,FMS 3 core Radiator, FMS 4:10's