EHA and O2 sensor on racecars
 

To the track guys out there , i was wondering how they
set there mixtures on the track with there MB's? you guys running O2 sensors or EHA on or off?

I know with the old CIS porsches , they disconnect the O2
run a few laps to warm up the engine and richen the mixture
, then set it back to drive home with.

or is there racing O2 sensors and EHA?

thanks
Dave

GO KIMI!!!!!!!!!!

I use a O2 sensor to supply display with fuel throttle mixture info. The EHA stays unplugged except on test days when I have a rheostat connected. Then I set differential pressure for those conditions.

Doc, does unplugging the EHA throw the system into open loop?

Unplugging the EHA elimanates ALL electronic inputs & then puts the system into FOM(fixed operational mode)
The injection system is mechanical! The electronics only there to enhance emission levels. & for cold running.

So if an M103 is guzzling gas (10mpg) in both FOM and closed loop, then it is more likely a mechanical problem?

MB Doc .
Are you using a stock MB fuel press. reg? or do you have a adjustable one? Does bosch make injectors that flow more fuel for the 16v?
Also how are you figuring you are riching the mixture , from the O2 meter? About how many turns of the mixture screw about? (summer day)

I really like how the 16v pulls with the EHA off but it sucks following someone slow, may be I can rig a switch on the dash
to turn it on and off at will:D

The 16V uses a pressure regulator that opens around 5.8 bar.
The 420 & 560SEL's fuel pressure is 6.2-6.4 bar. The only difference is the regulator. The injectors from the 420/560 engines also flow more fuel, but the line connections are different.

Yes the O2 sensor info to my meter allows good info on fuel mixture.