air fuel ratio

[4g63awdtalon]

how much does cfm affect the air fuel ratio

[kpt4321]

Err... none, and a lot? That's a really difficult question to answer, because it does not make much sense.

CFM is cubic feet per minute, which refers to how much air you are flowing. A/F ratio is the ratio between the amount of fuel and the amount of air entering your motor.

[4g63awdtalon]

sorry about the wording
with a bigger turbo and the greater amount of cfm that is flowing will this affect the amount of fuel needed to be added to keep the correct air fuel ratio

[CanadianTSi]

Think about it....

If you have more air, your need more fuel to keep the mixture correct.

[98spydert]

Originally Posted by 4g63awdtalon

sorry about the wording
with a bigger turbo and the greater amount of cfm that is flowing will this affect the amount of fuel needed to be added to keep the correct air fuel ratio

If you mean "Will throwing a bigger turbo on make my A/F ratio change" then theoretically no. Any air being pulled through the MAS, no matter if a large amount or a little, will be compensated for and fuel will be added.

Now wether or now your stock fuel system will be able to add enough fuel for a large turbo is a hole different question.

Hope this helps

[kpt4321]

Right on. That's exactly correct.

The ECU knows you need more fuel and tries to compensate. However, in some cases (a lot, really) it doesn't have enough headroom to give you the fuel you need, because the injectors or fuel pump are to small.

[4g63awdtalon]

thanks for the help

kpt4321 do you have any sites or threads on tuning info that i could read to help with my tuning

[kpt4321]

http://users.wpi.edu/~ktarry/dsmtech/techindex.html

Try the SAFC tuning guide, the air metering article, and the how the SAFC works aticle.

[98spydert]

Just a friendly suggestion. Read up and understand how the stock fuel and air metering systems work before learning and installing aftermarket parts. If you already know it, good on ya