pulley problems

[gt9stang5]

I have a 95 gt and i changed my puuleys to BBK aluminum underdrive pulleys. When i changed them, my battery drops and my temperature increases. I think my belt isnt running fast enough or isnt tight enough because once I give it gas and the pulleys speed up, my temp drops and my battery charges. If anyone knows what i could do or has experienced this b/4 please let me know. thanks.

 

[noslow5_0]

I have a 95 gt and i changed my puuleys to BBK aluminum underdrive pulleys. When i changed them, my battery drops and my temperature increases. I think my belt isnt running fast enough or isnt tight enough because once I give it gas and the pulleys speed up, my temp drops and my battery charges. If anyone knows what i could do or has experienced this b/4 please let me know. thanks.

its the underdrive pullies!!! the whole idea behind them is to decrease the amount of time it takes to spin the pully, which inturn slows down the pully and the accessory it is spinning. This results in some charging and cooling issues. I dont know what you would be able to do for the cooling problem except to upgrade it along with a bigger alt. like a 135 amp.

 

[gearheadboy]

RIGHT ON! thats what underdrives do, slow the alt (less charge at idle) slow the water pump (less coolant flow through the radiator and engine) You can upgrade the alternator if you like, and changeing thermostats may help, but if it isn't overheating, forget it, and drive it! The new cars I work on run about 234 before the fan even comes on! and it kicks back out at like 214.

 

[gt9stang5]

its the underdrive pullies!!! the whole idea behind them is to decrease the amount of time it takes to spin the pully, which inturn slows down the pully and the accessory it is spinning. This results in some charging and cooling issues. I dont know what you would be able to do for the cooling problem except to upgrade it along with a bigger alt. like a 135 amp.

Thanks. I think im going to get a high flow water pump and change my alternator to a 200amp one. If it is what you say it is, and i hope it is, these mods should do the trick right?

 

[leakyfaucet]

Well, not to nit-pick, but wouldn't putting in a high flow water pump and a higher amp alternator almost negate the benefits of having underdrive pullies? Not to mention the cost? For the price of what you want to do, you could put the stock pullies back on and get a new intake manifold, and have no cooling/charging issues and still have more power.

 

[gearheadboy]

Well, not to nit-pick, but wouldn't putting in a high flow water pump and a higher amp alternator almost negate the benefits of having underdrive pullies? Not to mention the cost? For the price of what you want to do, you could put the stock pullies back on and get a new intake manifold, and have no cooling/charging issues and still have more power.

Gonna have to agree. IMO you slowed down the water pump (less drag) only to add a bigger impeller pump (more drag) slow down the alternator (less drag) add a heavier (weight) higher amp alternator, that does the trick (more drag to do the trick) . So what have you got? $50 pulleys+ $150 pump+ $150 alternator= more weight from the alternator, skinned knuckles, and $350 less in the wallet. Car runs the same. Take the pulleys off, sell um on ebay, buy a set of gears and have them installed. You like them much better in the seat of your pants!

 

[Michael Yount]

Yup - you're experiencing what many do with underdrives; some don't. I pulled them off mine (previous owner put them on) -- and traded someone even up for a stock set to put back on. Got rid of my overheating and undercharging problems. For a dedicated racer, underdrives are a no-brainer. For a street car, especially with a/c, you have to be careful depending on how it's used, part of the country (hot weather), etc. I'd sell 'em if I were you.

 

[gt9stang5]

Thanks

Well I finally fixed my problem with the pulleys. Just before I was going out to buy an alternator and water pump, I thought of just changing the belt to 3/4in smaller. So I did, and turns out my alternator charged up and my heating problem was nothing more than my radiator fan wire was not connected. To sum everything up, I changed my belt 3/4in. smaller, and clipped on my radiator's wiring(I had disconnected it to reach the crank pulley upon installation).
Thanks though for all your replies.