|
Well unfortunately my engine developed rod knock (I think I know why, it's a long story), so it's going to come out. That means I finally get to measure the pulleys and underdrive the accessories.
After I got my car a few months ago, I immediately noticed that the factory Toyota ECU likes to keep it idling above 800rpm with lights off and 900rpm with the lights turned on, which is pretty crazy. That means I really don't need to be spinning the accessories this fast.
I noticed Summit Racing has a crapload of alternator pulleys that are very cheap, I think I might as well get one if only for the bling factor, assuming I find one with the right bore. Spinning an alternator 10% slower would free a few dozen watts of bearing/fan losses, and somewhat reduce iron losses.
The water pump pulley will be interesting. The stock pulley looks to have slightly under 10mm clearance to the tensioner, and is somewhere around 100-110mm in diameter. If I use up 6mm of that clearance to reduce the speed of the pump by ~11%, reducing its power consumption by 30%, that would be pretty good.
|