A guy at work showed me this:

http://www.srmotorsports.com/RX8_Power_Pulleys.html

 

i don't think anyone makes and underdrive pulley kit for the S. i know they make lightened pulleys. but they are still stock size.

 

I wonder why no one makes underdrive pulleys for the S. Are the stock ones that well optimized??

 

well you ahve an advantage to a lightened pulley as opposed to an underdrive as that you dont sacrifice power to everything on the belt, underdrive would cause the belt to spin slower and you would lose AC power, alternator energy, etc.

i know in the 3/S world (sorry i always bring this up, its what i know most about), puting on an underdrive pulley also requires the removal of the harmonic balancer, no one has had problems with this, but its somethign to think about

 

where could i fighted a lighted pulley for a NA engine?

 

i think ricks sells them.

 

thats what i read, but i cant seem to find em on the site. can anyone help me out?

 

underdrive pulleys for the crankshaft might mess up the balance
cyrus a i have the lightened pulleys
u wont feel much but it does idle smoother

 

oh aight thanks, i got other mods to save for anyways

 

How is an equally weight distributed pulley going to cause a new ("mess up") balance issue? The stock one has equal weight distribution and so will a lightened one.

Honda doesn't use the pulley for counter-balancing.

We run them on FDs, FCs, and SAs (all RX-7s) all the time - it's fairly regular for 13B-REWs to see a 10-15 hp increase with just the addition of eccentric shaft, water-pump, and alternator pullies (assuming all other bolt-ons).

As far as undriven accessories go, no one even notices it being an issue. In fact, undriven water-pumps tend to help with cooling as a typical centrifugal water-pump usually cavitates at high rpms.