Hell no...I couldn't even tell a difference when I had them on my turbo coupe, except that they made the lights dim at idle...
Honestly, it's $90 for two pulleys (crank & alternator)...you don't even get a water pump pulley. Also the smaller crank pulley is hard to line up with the timing pointer on the timing cover, and when I got mine about 4-5 years ago the crank pulley didn't even have a timing mark in it! I had to make one.
You'd be better off spending your money on suspension stuff.