What kind of realistic gains should I expect from a set of underdrive pulleys from AEM or UnorthodoX?

 

your tranny shot. too much stress on the tranny for that.

 

What? My tranny isn't shot.. I just have a damaged Alternator pulley so I need to replace them. Are you saying that my transmission will get damaged from underdrive pulleys?

 

(silverstreakin)

im on my wifes name...i love the underdrive on my corolla...they sent me a dyno sheet showing 10 hp and 12lb/ft improvement...of course thats on the older model too...

ive never heard of a tranny getting shot because of underdrive...it does increase wear on the crank though...

 

1 of my friend had a UR underdrive pulley and his tranny went a little later, his friend too had one and it blew is tranny.. they said never get aftermarket underdrive pulleys.. if you drive it normally with a little street fun he said your tranny will last another 30K or so, but if you beat on your car look at about 10k.