[driven06]

i have a BD-10 Powerdyne w/ the 6lb pulley. i want to upgrade to the smaller 9lb pulley. do i need to replace anything else? or can i just swap pulleys and drive?

[jeffreyt944]

I have swapped pullies on a supercharger on a friends thunderbird and all we did was pull the belt off and swapped the pulley. You could feel the difference, it was awsome.

[driven06]

did you mess with the timing at all? do i need to retard the timing when it is boosting?

[driven06]

does anyone know if i can simply swap the pullies? 6lb for a 9lb

[Blk Stallion]

I swapped a 9# for a 15# as long as your belt fits right and you adust the tensioner. Just listen for pinging at the worst you my need a smaller belt and you might have to back the timing a little if it pings. Just find an open road and run hard in 3rd if it picks back the timing a little at a time until it stops. Actually are you stock other than the supercharger? Do you have and FMU? I had to up my injector size to 30# and get rid of the FMU. I had fuel stavation issues with the 9lb pulley but there are some people who can with stock injectors. Also if you're not already running colder plugs you should change them 1 or 2 heat ranges colder gapped at around .32

[driven06]

no its not stock, 303 cam, FMU, MAF, larger throttle body. its running fairly rich now so i think i may be fine on the fuel. any suggestion on which plugs to use? thanks!

[Blk Stallion]

I used autolite 24s copper.= 1 heat range cooler than stock. I beleave Autolite 23s would be fine too=2 heat range cooler. I've heard of people using denso and bosch irdium and what not but thats more expensive and I'm not sure its worth it. Mortorcraft is probably the prefered choice but I heard autolite and Motorcraft are the same thing. Hard to say I saw on the Autolite box Made in China designed in USA soo for my sake I hope there still desent quality.