Tricking the air flow sensor

[Roastin944]

hey everyone,

I read about the callaway conversion and one of the things they did for more fuel is "tricking" the afm to thinking it was always cold or something which causes it to dump in more fuel. Have you heard of this? How do you do it? Thanks

[highboost951]

Link engine management may help you out or the guys at guru, get rid of the afm and don't use a maf either, switch the system to use a Map sensor, I think this will be your safest route.

[tholyoak]

Callaway increased fuel in a few ways

1) Larger injectors which required increasing the spring tension on the AFM so that the car wasn't running really rich when not on boost

2) Fifth injector in custom manifold just ahead of the TB. Its opperation controlled by a separate 'computer' which measured boost and engine speed and cycled the injector accordingly

3) 1lb boost switch, at 1psi of boost the TPS was grounded to trick the DME into providing full throttle enricment under boost.

Today I'm sure there are more elegant ways to do it by replacing the fuel injection system with a Motec or similar, but this allowed you to retain the Bosch system.

Todd

[todwic]

one way is to take off the cover of the afm and back the spring off a notch or two. I haven't done this myself, but scuttlebutt sez it'll increase fuel to the cyl. by making the flap easier to open, making the afm think there's more air going thru than actually is.

[Frank B]

*sigh* .. leave it alone and buy a turbo... (laughing)
Frank B

[afx]

That does not work except on Euro944

Adjusting the dial on the US AFM does nothing? I could not see how that would be true. How would it only work on the euro models?

[divezic]

MORE FUEL DOES NOT MEAN MORE POWER. To increase power you need to increase air flow. Increased airflow will increase fuel being delivered and, therefore, increase power. To just increase fuel flow will possibly decrease power.

[Blackfoot]

fuel burns with the highest efficiency (most power) at a ratio that's something like 14:1...14 parts of air to 1 part fuel. so unless you find some way to increase the air flowing into the engine, increasing the fuel won't help at all, unless for some reason the car was running lean, and you get back to the ideal 14:1.

[Roastin944]

i am not asking how to force more fuel with no extra air, i am boosting it and will need more fuel, so i wanted to know the best way to obtain a correct ratio when boosting it. So a 3 bar fpr from powerhaus is the best? Thanks

John