dyno charts for underdrive pulleys? mpg?
I have an 04 zhp 330. I have searched and couldn't find any dyno charts from you guys before and after with under-drive pulleys. Also I didn't see any mention of mpg after install. I have gotten a new job where i put a LOT of miles on my car and can justify a performance mod to the better half if the mpg are there.
Anyone have some info/charts for me?