No experience on the F40 but i had one on my F21 M135i and i,ve literally just put one on my F56 Cooper S last weekend and in my opinion they are great for the money
I did,nt expect much to be honest but on the M135i the mid range torque was much much stronger,and on my Cooper S i,ve got the 3 channel model and its laugh out loud faster mid range,i,m shocked just what a difference its made.
Steve
I did,nt expect much to be honest but on the M135i the mid range torque was much much stronger,and on my Cooper S i,ve got the 3 channel model and its laugh out loud faster mid range,i,m shocked just what a difference its made.
Steve