I have a 95 Z28 and I am getting ready to purchase underdrive pulleys. There are a couple different options. BBK has just a crank underdrive pulley and RKsport has a kit with both the crank and the alternator pulleys. The Rksport kit is a 34% reduction in the crank and 15% for the alternator. Which would free up the most power and approx. how much?

 

I have the March 2-pulley set on my 97SS. Don't know if you get much less parasitic drag, but I believe I get some seat-of-pants improvement in off idle throttle response.

The March pulley piggy backs onto the inside of the crank balancer pulley rather than replacing the pulley. The alt. pulley replaces the alt pulley and if you get an alt. pulley consider that you may have to remove and install it with an impact wrench since it wants to turn with a regular wrench.

Don't know about the other UD pulleys, but have no problem with the quality of the March system.

You will also have to get the S belt with the March set. Don't know about the others.

 

Thank you for the input. I just looked at the march pulleys. I think I will go that route. Just trying to get more low end power to the rear.

 

My buddy has an ASP pulley and you could tell the car did rev a little quicker.

 

Was the crank pulley hard to get at?What did you have to take out to get to it.Aren't pulleys supposed to save on gas mileage as well.

 

Your better off just saving your money off the little bolt-ons with questionable gains such as the pulleys, airfoil, etc. and dump it on a nice set of headers, mail order tune, rockers, etc. and get some proven gains. A couple friends who I have talked to about the underdrive pulleys didn't report any noticable gains.

 

i don't think mine does anything except make my lights dim and **** off my stereo

 

I got the Underdrive pullys From Rk sport put them on , 2 days later took them back off. Then i i got the March pulley , very little difference. You want some extra torque, get some headers or 1.6 RR.

 

I noticed a small gain with ASP crank pulley.
About the same gain as 1.6 RR which I did later, and ASP
was just a tiny bit easier to install .
Get a smaller pulley for the alternator if it's an auto .

 

I just installed my ASP crank and alternator pullies yesterday. HUGE weight difference from the stock crank one to the aftermarket one, but the alternator one was about the same with a little weight loss!!! I think it makes a difference comparable to driving your car with the AC on and off (power gain feeling). I love mine and have no light problems.....yet Another thing is the ASP bolts they give you are WAY too long and almost was going to destroy my opti , glad I noticed it and used spacers, that would have PISSED ME OFF---

 

Yea, i remember having to cut those bolts down to size also. When i installed my Scorpion 1.6 RR , OMG what a huge difference. But then again my LT1 is definitely a factory freak. It Dyno'd Stock at 303hp and 299rwtq.