[zenmaster]

Hmm all this time I was thinking the O2 sensor reading was used by the DME to adjust fuel trims.

[DKX4///M]

Originally Posted by zenmaster

Hmm all this time I was thinking the O2 sensor reading was used by the DME to adjust fuel trims.

So did Il until I got my NYS Inspectors license...

For example, Ive unplugged the OEM 02 on catless cars with a seperate wide band 02 ir exhaust "sniffer", It makes o difference in AFR wot or w/o load...

If anyone wants I can post the charts from the official BMW Service Manual that show the 3-4 major things the DME uses to determine fuel.
Last example, if the 02 was used to determine such, meth, e85, etc ...fuels with low potential energy need completely diff AFR than the reg 14.7, 11.5-12.5...While typically you neeed about .5g/hr BSFC (Brake Specific Fuel Consumption), Meth needs more than .7G/hr to reach a stoich mixture.

BTW many tuners arent even aware of this so make sure your tuner knows there stuff or they will have trouble getting results, especially w a car as agressively tuned as the M2.

[DKX4///M]

Originally Posted by zenmaster

Hmm all this time I was thinking the O2 sensor reading was used by the DME to adjust fuel trims.

So did Il until I got my NYS Inspectors license...

For example, Ive unplugged the OEM 02 on catless cars with a seperate wide band 02 ir exhaust "sniffer", It makes o difference in AFR wot or w/o load...

If anyone wants I can post the charts from the official BMW Service Manual that show the 3-4 major things the DME uses to determine fuel...

Also if the 02 was used to determine such, meth, e85, etc ...fuels with low potential energy need completely diff AFR than the reg 14.7, 11.5-12.5...a LAMBDA of 1 on 93 is 14.7 under little/no load, however on water meth a LAMBDA of 1 is much lower than 14.7 depending on WMI % of fuel.

[mike@x-ph.com]

Wagner Intercooler