Mark 1 AFM mod?

mr2tim · 10-05-2009, 12:23 PM

Some years back there was a popular modification that was being tried by us tinkering types of racers looking for that performance edge.

This modification involved popping the black flap on the AFM's top and moving the spring inside afew cogs and then reassembling/sealing the black top again.

The purpose of this mod was to facilitate a faster response of the "door" inside the AFM at a slower mass air speed passsing thru the AFM.

(Be forewarned that if you went to far, that is too many cog movements, it sent you into an "idle search" and you had to back off a cog or two.)

Has anyone been involved in this mod lately out there in ToyotaLand?

Jackstand Queen · 10-06-2009, 01:45 AM

I did this Mod. years ago on an N.A.

I noticed no improvement in performance.

It did cause the mixture to run too rich, and fouled spark plugs quicker, and reduced MPG.

Overall . . . this Mod is now . . . . so five minutes ago . . . because it has drawbacks, and doesn't deliver the HP.

Papo J · 10-06-2009, 07:55 AM

That's because you're supposed to lean out the mixture not richen it up, a leaner mixture caused by the AFM flapper will also increase the timing so be very careful with it. IMO, is not worth it.

ToyotaTechGeek · 10-06-2009, 08:17 AM

i've done it on my SC and on several NA cars.

10-05-2009, 12:23 PM	#1 (permalink)
mr2tim SUPERcharZed ToyZ RacZer Join Date: Mar 2008 Location: South Florida Posts: 690 Thanks: 2 Thanked 41 Times in 38 Posts My Google Map iTrader Rating: (2/100% )	Mark 1 AFM mod? Some years back there was a popular modification that was being tried by us tinkering types of racers looking for that performance edge. This modification involved popping the black flap on the AFM's top and moving the spring inside afew cogs and then reassembling/sealing the black top again. The purpose of this mod was to facilitate a faster response of the "door" inside the AFM at a slower mass air speed passsing thru the AFM. (Be forewarned that if you went to far, that is too many cog movements, it sent you into an "idle search" and you had to back off a cog or two.) Has anyone been involved in this mod lately out there in ToyotaLand?

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10-06-2009, 01:45 AM	#2 (permalink)
Jackstand Queen Cage Fighter Join Date: May 2008 Posts: 677 Thanks: 52 Thanked 56 Times in 53 Posts iTrader Rating: (1/100% )	I did this Mod. years ago on an N.A. I noticed no improvement in performance. It did cause the mixture to run too rich, and fouled spark plugs quicker, and reduced MPG. Overall . . . this Mod is now . . . . so five minutes ago . . . because it has drawbacks, and doesn't deliver the HP.

10-06-2009, 07:55 AM	#3 (permalink)
Papo J 6SPD GTE Join Date: Sep 2006 Posts: 189 Thanks: 1 Thanked 19 Times in 18 Posts iTrader Rating: (0/0% )	That's because you're supposed to lean out the mixture not richen it up, a leaner mixture caused by the AFM flapper will also increase the timing so be very careful with it. IMO, is not worth it.

10-06-2009, 08:17 AM	#4 (permalink)
ToyotaTechGeek Giapetto is NOT my dad! Join Date: Mar 2005 Location: ...boosting mid-corner Posts: 568 Thanks: 7 Thanked 13 Times in 13 Posts My Google Map iTrader Rating: (1/100% )	i've done it on my SC and on several NA cars.