Cooling and Charging issues solved(Damn underdrive pullies)

Rick 91GT · 08-02-2002, 05:26 AM

Well I fighting the car running hot (205-210) cruising through town and at low rpm. I have a awesome Ron Davis Racing Alum rad, it flows great, high flow 180 thermo, a high flow Stewart Water pump, and a 16" Perma Cool fan.

I called and was speaking to the tech guy at Stewart and the first thing he asked me was " Are you running stock pullies or underdrives and is your crank pulley larger then the water pump?"

I replied Underdrives..he said that's your problem, the crank pulley needs to be 10-35% larger then the waterpump to spin the waterpump hard enough, if not you are not getting the most out of the pump. SO I swapped a set of stock pullies back on, I had a hard time getting the car to run 180 degrees, with the fan off. If I turned the fan on it ran around 165-170 degrees no matter how hard I ran it.

As far as my charging issues, my stock 65amp alt was bad. I upgraded to a 140amp and man what a difference, car pulls 80amps at idle! and 125amps at 3000 rpm. What a difference, no more drop at stops even with the elec fan on. I should have upgraded a loooong time ago:doh:

08-02-2002, 05:26 AM	#1
Rick 91GT Procharged! Join Date: May 1999 Location: Hanover, PA Posts: 1,539	Cooling and Charging issues solved(Damn underdrive pullies) Well I fighting the car running hot (205-210) cruising through town and at low rpm. I have a awesome Ron Davis Racing Alum rad, it flows great, high flow 180 thermo, a high flow Stewart Water pump, and a 16" Perma Cool fan. I called and was speaking to the tech guy at Stewart and the first thing he asked me was " Are you running stock pullies or underdrives and is your crank pulley larger then the water pump?" I replied Underdrives..he said that's your problem, the crank pulley needs to be 10-35% larger then the waterpump to spin the waterpump hard enough, if not you are not getting the most out of the pump. SO I swapped a set of stock pullies back on, I had a hard time getting the car to run 180 degrees, with the fan off. If I turned the fan on it ran around 165-170 degrees no matter how hard I ran it. As far as my charging issues, my stock 65amp alt was bad. I upgraded to a 140amp and man what a difference, car pulls 80amps at idle! and 125amps at 3000 rpm. What a difference, no more drop at stops even with the elec fan on. I should have upgraded a loooong time ago:doh: __________________ *D/R 10108 NMRA Drag Radial, 25.5 chassis, F1R* *Check out RNH Performance Performance Engines and Custom Fabrication.* *From Mild to Wild we can build what you want, when you want it.* FOR SALE Stainless Steel Torque Box Supports