As above, is this item worth upgrading to?Its jus now cams are upgraded my car will rev upto and prob past 6.5k revs, so dont know if this will start causing damage, so wondered if this would be a worthwhile upgrade?Also (iv prob asked before) are the CFM underdrive pulleys any good? Do they do as they say and allow car to rev easier and wud it help if revvin high (6/6.5k revs)?Thanks, Matt.

 

Are they american by any chance ?, the claims sound american drivel.
A underdriven pulley will offer no benefit whatsoever, the idea that a laternator is a large power consumer is ancient, they are self regulating in that they will only cause enough drag to keep the leckies running and no more, these are normally ecu controlled on yours, so if going slower it just loads the alternator more.
They're just for gimmick people and blingy people, much like the yank flywheels that due to lightness give you + 20bhp, complete crap, they give you zero bhp, just allow faster acceleration(less rotational mass) but bhp remains the same.
tabetha

 

yea id seen them somwhere before, then on pumaspeed so checked with CFM direct as its cheaper that way.Thats why i always check up with wot i read. I wasnt expectin big BHP, just thought that if it gave a worthwhile gain in acceleration then it mite be worthwhile. Also the alternator pulley thought mite be useful as my car revs to red line and beyond now without dyin.This is the alternator pulley:http://www.pumaspeed.co.uk/showdetai...?productID=575 .The two piece underdrive pulleys is here:http://www.pumaspeed.co.uk/showdetai...?productID=538 .Matt