air fuel ratio

[robdf2]

How can i tell what my air fuel ratio is?
i know it can be done when on a rolling road , i have vag com or more recently known as vcds can this show me waht my air fuel ratio is? if so would appreciate some info pointing me in the right direction
Thanks

Rob.

 

[-pseudonymous-]

Log block 031 in VCDS which gives you your actual and specified Lambda readings, then multiply them by 14.7

For example - 0.81 x 14.7 (stoich) = 11.9 AFR

Just a note, you may already know, but VCDS logs are saved in .csv format which can be opened in Microsoft Excel. It is very handy opening them in Excel and creating graphs to compare results.

 

[-pseudonymous-]

Oh and here is a rough guide and some handy measuring blocks that may be of use to you...

http://www.goapr.com/support/datalogging.php

 

[robdf2]

thanks for the info , so what should a good AFR reading be?

 

[RobH]

Around 12.5 i think

 

[Damoegan]

Around 12.5 i think

Depending on the state of tune that is....

 

[robdf2]

Around 12.5 i think

cheers Rob , whats the tolerance on that ?

i have logs showing requested 1 actual .98 so im guessing an AFR of 14.406 is ok just out of intrest how do i tell if its lean or rich from the calculated number?

 

[Damoegan]

Is that on WOT, Rob?

If so then that is VERY lean and not good at all...

 

[RobH]

Mine has never run lean, always seemed to run a tad rich.

 

[robdf2]

thats 2560 rpm

further up the range at 5200 rpm same figures

on another run at same rpm requested .91 actual .89 and at 5200 rpm requested .83 actual .82

so whats it all mean then lol

 

[RobH]

Ah i see you was talking to the othe Rob Damo

 

[Damoegan]

When under WOT full load you want to have a AFR of 12.5 or under.

The lower the AFR the more fuel thats being added..

 

[Damoegan]

Ah i see you was talking to the othe Rob Damo

 

[robdf2]

thanks for the help guys
just one last thing if my car is running lean im guessing its my ecu adjusting ? or is there a way or what affects makeing it running a tad richer?

 

[Damoegan]

thanks for the help guys
just one last thing if my car is running lean im guessing its my ecu adjusting ? or is there a way or what affects makeing it running a tad richer?

What map you running, Rob?

 

[RobH]

If your standard which i think you are, you should be running fine but obviously with an afr of 14.4 your not.

Ive no idea how to adjust a standard map, are we sure those calculations are correct from the vcds????

Obviously with Revo you just add a bit more fuel with the sps.