I'm interested in underdrive pullies but I was wondering if I'm still able to install a car amplifier with it. To my understanding, underdrive pullies slow down the alternator.
Does anyone also know how much of a horsepower gain is there when adding underdrive pullies?
I have underdrive pulleys and a 1000 watt amp. I have no problems. As long as you don't let it sit idling for a long time running your stereo real loud, it shouldn't drain your battery/alternator or anything. I noticed quite a nice gain with my pulleys. They say they're an easy 10 hp (flywheel of course) which I guess is maybe 8 or 9 at the rear wheels. I believe it.
I have UD pullies and about 1000 wrms in my system and if I have the lights on, or the air conditioning/heat on, my voltage was dropping to like 11 volts. I bought an optima yellow top and now I dont drop below 12 volts.
I have a rockford punch 250 amp and panasonic head unit(100 rms I think) and no problems, should be fine as long as you dont have a very powerfull amp.