When I heard about the Lexus Air Flow Meter (AFM) and injector upgrade, I new I wanted to do this to my Supra.  This upgrade consists of replacing the stock AFM with one from a Lexus V8.  I don't which exactly, at the time those in the know were keeping their secrets close to the vest.   The Lexus AFM is 25% larger than stock so it flows more air.  Couple this with 550cc injectors for 25% more fuel and you get a performance increase without having to modify the computer.

Since the electronics are the same, all that I had to do for this part of the upgrade was to remove the old AFM housing and install the new one. 

1- As the Lexus AFM is larger, it will take some work to get your stock accordion hose over the end.  Make sure that you have a hose that is in good shape and still very flexible or it will be sure to crack when trying to fit it over the larger AFM.  If not, get an 89+ hose from Jay Mark's Toyota as it is considerably less expensive and the exact same part.

1- The old hose clamp will not fit the new AFM.  I just bought a 4 inch hose clamp from local hardware store. 

2- There is supposed to be a longer adjustment screw added as part of the AFM upgrade.  Some have said they get by without it.  I don't have the longer adjustment screw and have not been able to get the air/fuel mixture just right.  My car runs rich due to this.

3- Be careful if you donot do this mod along with larger injectors, lean engine conditions are very hazardous.

4- Be sure not to clean or otherwise mess with the honeycomb.

This along with the injectors is a great upgrade, it actually increased my gas mileage.  Be forewarned though, the injector part is not easy as it requires modification of the wiring harness.  All in all this was well worth the money.

The electrics assembly stays the same.

The Lexus AFM is noticeably larger, flows more air both metered and unmetered.