[mr.goodkat]

I've seen this question here and there but haven't found a dedicated thread to it.

When doing underdrive pulley's is there anything else I should be adding or already have on my car? Do I have to use a different belt? Is the sequence of the belt installation different from the original? Are they're different kinds and sizes of pulleys?

This is for a daily driver. Mainly street driven as opposed to highway.

Thanks!

-MR.GOODKAT

[EagleAutosports]

Good question.

The belt routing is the same.

If you get street pulleys, you are supposed to be able to use the same belt. There's times the belt has to be changed, depending on what accessories you're running.

There are different size pulleys, in accordance to their type. Street pulleys are bigger than race pulleys. There are slight differences between standard underdrives and the Power & Amp series by March. The ratios are slightly different to minimize the lower output caused by the bigger alternator pulley.

Other things aren't required like a high amp alternator, but it counteracts the lower output so it helps.

[justin73]

I have underdrive pulleys on my 92 5.0 mustang i would reccomend leaving the stock water pump pulley on if you dont you will run into overheating issues if you do alot of town driving.I also have a fluidyne radiator and heavy duty clutch fan that didnt help much hope this helps you.

[drell93cobra]

I put some machined aluminum pulleys on mine and they work fine. I left off the alternator pulley because a couple people told me they had issues burning out alternators quicker with the pulley changed. I had to replace the belt with a shorter one due to pulley size differences. Once you install the new pulleys, take a string and wrap around the pulley configuration as if it were the belt. You can take the exact length string of the pulley routing to a auto parts store and find the proper belt length.

[greg93]

Had them on my 93 cobra but sold them to get a supercharger setup. I noticed the lights would go a little dim at red lights. I was really not impressed with them....

[92Notchback]

i recently put them on my 92 coupe and noticed the alternator is not charge up right and the car is over heating

[mr.goodkat]

Good info everybody. Thanks.

Maybe I shouldn't even mess with them. Sounds like more trouble than they're worth.

[cindys_sn95]

mine were on the car when i got it. no problems, but i don't think i'd bother if they were not already there.

[50fanatic]

I just installed the underdrive crank pulley and a 130 amp 3g alternator.

[noble steed]

My underdrive pulleys work fine, but I also have a new alternator, radiator, and pretty much everything new under the hood. Never noticed a difference in charging on the gauge or any increase in temperature.