I would think that any difference in cam or ignition timing with this device is going to be very minimal,its a copy of this Comp Cams peice;
The timing chain would have to have an awful lot of stretch in it before there would be an advantage to using this.And to call it a variable valve timing control device seems to be a bit of false advertising,its is a tensioning device,period.And 7-30 hp gain,this isnt even realistic !!! And the parts are affected by wear and need to be checked on a regular basis.Just another case of someone trying to lighten our wallets with an unecessary peice. JMO !!!