Underdrive Pullys

bjones · 01-11-2009, 06:49 PM

Do they affect anything related to the alternator's output or the ability of the water pump to run efficiently and well?

I have a Vortec 350, and was looking at a set of pulleys.

merlin5577 · 01-11-2009, 06:51 PM

Generally no. Most kits have a larger crank pulley and smaller alternator and water pump pulleys. This changes the overall ratio of the accessory drive slowing it down, without changing the drive speed of the alternator and water pump. A nice modification for any truck.

bjones · 01-11-2009, 08:18 PM

So a safe upgrade?

Im sold.

72'CaminoKid · 01-11-2009, 08:25 PM

how much HP / torque or whatever will this save you? is it really worth it? i've heard them talked about before but never really looked into them

gmctrucks · 01-11-2009, 08:32 PM

Yes a safe up-grade your going to love the power difference. Get back to us because im always bragging it did a whole lot to my 93 5.7 engine Ext/Cab.

merlin5577 · 01-12-2009, 02:40 PM

Quote:

Originally Posted by bjones

So a safe upgrade?

Im sold.

Yes it is a safe upgrade, as long as long as it is installed correctly.

Quote:

Originally Posted by 72'CaminoKid

how much HP / torque or whatever will this save you? is it really worth it? i've heard them talked about before but never really looked into them

It depends on the vehicle, previous mods, mileage, and a bunch of other factors but average 5-15HP.

01-11-2009, 06:49 PM	#1
bjones Full Member Join Date: Oct 2008 Posts: 43	Underdrive Pullys Do they affect anything related to the alternator's output or the ability of the water pump to run efficiently and well? I have a Vortec 350, and was looking at a set of pulleys. __________________ 1997 GMC Suburban, RIP 12/7/2008 Vortec 5700 V8 300HP 380Ft-Lbs Torque (certainly not stock) 4L60E Tranny 238K Miles A truck, a brother, and a friend to the end.

01-11-2009, 08:18 PM	#3
bjones Full Member Join Date: Oct 2008 Posts: 43	So a safe upgrade? Im sold. __________________ 1997 GMC Suburban, RIP 12/7/2008 Vortec 5700 V8 300HP 380Ft-Lbs Torque (certainly not stock) 4L60E Tranny 238K Miles A truck, a brother, and a friend to the end.

01-11-2009, 08:25 PM	#4
72'CaminoKid Senior Member Join Date: Jun 2005 Posts: 2,756	how much HP / torque or whatever will this save you? is it really worth it? i've heard them talked about before but never really looked into them __________________ 99 suburban xlt 96 silverado 91 wrangler (my baby ) 08 Honday shadow 750 (my mistress)

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01-11-2009, 06:51 PM	#2
merlin5577 Banned Join Date: Nov 2008 Posts: 675	Generally no. Most kits have a larger crank pulley and smaller alternator and water pump pulleys. This changes the overall ratio of the accessory drive slowing it down, without changing the drive speed of the alternator and water pump. A nice modification for any truck.

01-11-2009, 08:32 PM	#5
gmctrucks Senior Member Join Date: Nov 2006 Location: Houston,Texas Posts: 4,035	Yes a safe up-grade your going to love the power difference. Get back to us because im always bragging it did a whole lot to my 93 5.7 engine Ext/Cab.