[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]

one-cam-sprocket-tooth-advance technique

Frank J. Bauer                                                                  
dassault systemes of America     email:fjbauer@dsavm.e-mail.com                 
Subject: one-cam-sprocket-tooth-advance technique                               
there should be little debate on the amount of cam advance provided by          
this technique.  if the cam sprocket has 45 teeth it's 8 degrees, 60            
teeth it's 6 degrees, etc. (360 divided by number of teeth)                     
(of course 45 tooth cam sprockets don't exist - gotta be an even number)        
i know the 8V VW has a 44 tooth sprocket which means about 8.18 degrees.        
if the audi has the same sprocket as vw (number of teeth, shaft diameter,       
key size and placement, etc) there is an excellent adjustable sprocket          
available from autotech sport tuning.  it can be adjusted +/- 4 degrees         
in one degree increments and has an indexing screw to prevent slippage.         
this may be more useful for those who will hit the knock sensor with            
the 8+ degree advance.  theoretically, advance should improve low end and       
retard should help top end.  interesting possibilities include adjusting        
one tooth AND the sprocket for +/- 4 to 12 degrees, but at some point there     
may be piston/valve clearance problems and diminishing performance returns.     
the piece is about $80 and AST's phone is 714-240-4000 (just south of LA).      
disclaimers: got one in my GLI and it helped bottom end noticeably;             
no financial interest; YMMV - atmo vs turbo, etc.