Aye,Aye Cap'.....reporting as ordered. Yea, I thought about the 10% under drive would be a help for the high rpm by pass of our cooling systems...but ya can't have something for nothing. Yes in theory at low rpms the pump will move less water so the temps would have to rise a bit.
I had thought a 10% reduction would give us a bit bigger cushion on the twisties so you can hold that 2nd gear longer in tight Essses. At low speeds the pump output would have to cause the temps to rise a bit just because the pump is moving less volume due to turning the impeller less. Ya can't have your cake and eat it too!
5500 rpms = the complete by-pass target rpm on a stock system. No circulation thru the rad core. 10% reduction in pump impeller speed = only yields a cushion of 550 rpms....which is useless if you're in 2nd gear @ 6500 thru a series of Esses! Drag racing application only is JMHO, if your a road racer this will not answer the sustained high rpm volume that gets by-passed because there are no radiators that can handle the volume our w/p's put out. I had thought about buying these but the radiator core is still the issue and I'm not calling some F1 team to make me a radiator that will handle 100 gpm flow.....it's cheaper to redesign the impeller to lower the flow rate, JMHO.
Tom
forgot this, in drag racing where engine acceleration is related to reducing rotating mass, these pulleys would contribute to less rotating mass so less hp is lost thru parasitic drag which leaves that hp to accelerate the car. Just like the Fidenza flywheels let the motor turn up faster than a D/M flywheel.