[Supras] REG Lex AFM bypass screw

[Dan Gyoba]

On 6 Sep 2007 at 0:44, Wade Tobin wrote:

> I thought the main reason for the screw was to allow head to go flush
> with the inside body?  This would raise fuel cut some over the stocker
> which doesn't go all the way out.  
> 
>   A few years ago I did some testing with the Lexus AFM screw using
>   the LM1.  I found that  all the way out only changed .5% A/F at idle
>   and .2 at the WOT.  Also, the car never changed it's running/driving
>   characteristics much during the test.  So, mine's been all the way
>   out ever since.  Setups can vary so much with FPR's, biggie backs,
>   injectors, turbo size, and altitude.  THe screw, IMO, is pretty
>   useless by today's standards - mostly from improved piggiebacks. 
>   But, if you run the exact same setup as Reg then the screw is
>   probably a good idea.:)

Well, if the car's running in closed loop mode, or has for about an hor or so, then the 
ECU should be learning to adjust the AF ratios based ont O2 sensor feedback, so that's 
not really a valid test.  You'd need to directly monitor the AFM's output with a measured 
flow in order to really see what changes it makes.

On the other hand, if after learning, the AF ratio changes at all, then that says 
something....

Dan Gyoba
'89 NA 452,562 kms, Turbo swap COMPLETE
http://www.abstractconsulting.com/~dan