i, ordered tow brake tune from innovative, for my 2007 6.0 powerstroke. i can ear the turbo brake working but not a lot because as soon as i let off throttle the torque does,nt stay lock so engine brake is minimal and rpm drop to 1000-1200rpm. is it normal?? is there a way to keep it lock?? im looking at BD exhaust brake, do any body know if it worth the money???