Coupla Delta Dash questions

Diz · 10-31-2002, 09:40 AM

DD users -

What values for the 'knock' readings are indicitive of a knock event?

Also, is the 'Rear O2 Sensor' voltage reading the one I can plug into the equation: v * 14.7 = A/F ratio ?

TIA

PS - Yep, I did do a search & mail EcuTek already.

* Registered users of the site do not see these ads.

Mulder · 10-31-2002, 10:20 AM

The rear 02 sensor is after the cats and is used only to measure catalyst efficiency, it does not indicate A/F ratio.
The front sensor is a wideband unit and does not read in voltage like the rear or a conventional 02 sensor. The parameters for it are current and resistance, and the DD also shows A/F correction and learning data. There is no direct reading for A/F ratio and I don't know if there is a simple way to calculate it based on the readings.

Diz · 10-31-2002, 11:49 AM

The rear 02 sensor is after the cats and is used only to measure catalyst efficiency, it does not indicate A/F ratio.

Rats. I was afraid of that. Thanks for the input.

Jon [in CT] · 10-31-2002, 02:01 PM

The DeltaDash parameter "Air/Fuel Sensor #1" is reported in terms of "lambda" (λ), which is defined as actual air/fuel ratio divided by the fuel's stoichiometric air/fuel ratio. The limits on the lambda values that the ECU reports are 0.76 (rich) and 1.72 (lean). When the actual lamda is outside that range, the limit value is reported. Assuming premium gasoline's stoichiometric A/F ratio is 14.5:1, 0.76 and 1.72 correspond to sensor A/F limits of approximately 11:1 and 25:1, respectively.

I'd ignore the DeltaDash "Knock Signal 1" parameter and focus, instead, on the "Knock Correction" parameter. Large positive values indicate the absence of detected knock.

Diz · 10-31-2002, 04:11 PM

Excellent. That is EXACTLY what I was looking for. Thanks.

-paul

rlavalle · 11-01-2002, 11:33 AM

So we can use the Delta Dash to read the WRX wideband O2 sensor instead of having to buy a separate wideband O2 sensor/interface/display for tuning?

That would be great!

Russ

Gaspipe · 11-05-2002, 08:15 PM

Quote:

Originally posted by Jon [in CT]
I'd ignore the DeltaDash "Knock Signal 1" parameter and focus, instead, on the "Knock Correction" parameter. Large positive values indicate the absence of detected knock.

Jon [in CT]:

What would a typical 'large' value's range be in Knock Correction? I am typically seeing values of +4.5 to +6 under boost.

TIA,

StephenDone · 11-05-2002, 10:13 PM

Values of 4 and upwards generally indicate a happy state of tune and keeping a nice saftey cushion for conditions such as heat soak of the TMIC.

Jon [in CT] · 11-05-2002, 10:18 PM

I have seen logs where knock correction was as high as +10.5 at 6800 RPM under WOT in 2nd. In retrospect, probably any positive knock correction should be viewed as "good."

Gaspipe · 11-05-2002, 10:50 PM

S.D. & Jon:

I was somewhat stuck trying to figure out the KC values. The D.D. software is proving to be a pretty nice tool as I learn to actually decipher the data.

Anyhow, thanks!

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10-31-2002, 09:40 AM	#1
Diz Scooby Specialist Member#: 874 Join Date: Feb 2000 Chapter/Region: RMIC Location: Colorado Mountains Vehicle: 2003 Honda S2000 2004 Mazdaspeed MX-5	Coupla Delta Dash questions DD users - What values for the 'knock' readings are indicitive of a knock event? Also, is the 'Rear O2 Sensor' voltage reading the one I can plug into the equation: v * 14.7 = A/F ratio ? TIA PS - Yep, I did do a search & mail EcuTek already. * Registered users of the site do not see these ads.

10-31-2002, 10:20 AM	#2
Mulder Trust no one Moderator Member#: 11170 Join Date: Oct 2001 Chapter/Region: Tri-State Location: NYC Vehicle: 02 WRX 05 GTO/11 Sonata(!)	The rear 02 sensor is after the cats and is used only to measure catalyst efficiency, it does not indicate A/F ratio. The front sensor is a wideband unit and does not read in voltage like the rear or a conventional 02 sensor. The parameters for it are current and resistance, and the DD also shows A/F correction and learning data. There is no direct reading for A/F ratio and I don't know if there is a simple way to calculate it based on the readings.

10-31-2002, 11:49 AM	#3
Diz Scooby Specialist Member#: 874 Join Date: Feb 2000 Chapter/Region: RMIC Location: Colorado Mountains Vehicle: 2003 Honda S2000 2004 Mazdaspeed MX-5	The rear 02 sensor is after the cats and is used only to measure catalyst efficiency, it does not indicate A/F ratio. Rats. I was afraid of that. Thanks for the input.

10-31-2002, 02:01 PM	#4
Jon [in CT] * Banned * Member#: 2992 Join Date: Nov 2000 Chapter/Region: NESIC Location: Connecticut, USA Vehicle: 02 WRX Sedan Silver	The DeltaDash parameter "Air/Fuel Sensor #1" is reported in terms of "lambda" (λ), which is defined as actual air/fuel ratio divided by the fuel's stoichiometric air/fuel ratio. The limits on the lambda values that the ECU reports are 0.76 (rich) and 1.72 (lean). When the actual lamda is outside that range, the limit value is reported. Assuming premium gasoline's stoichiometric A/F ratio is 14.5:1, 0.76 and 1.72 correspond to sensor A/F limits of approximately 11:1 and 25:1, respectively. I'd ignore the DeltaDash "Knock Signal 1" parameter and focus, instead, on the "Knock Correction" parameter. Large positive values indicate the absence of detected knock.

10-31-2002, 04:11 PM	#5
Diz Scooby Specialist Member#: 874 Join Date: Feb 2000 Chapter/Region: RMIC Location: Colorado Mountains Vehicle: 2003 Honda S2000 2004 Mazdaspeed MX-5	Excellent. That is EXACTLY what I was looking for. Thanks. -paul

11-01-2002, 11:33 AM	#6
rlavalle Scooby Specialist Member#: 18384 Join Date: May 2002 Location: Seattle 'burb (Kirkland) Vehicle: 2004 STi: 580 AWHP Java Black Pearl	So we can use the Delta Dash to read the WRX wideband O2 sensor instead of having to buy a separate wideband O2 sensor/interface/display for tuning? That would be great! Russ

11-05-2002, 10:13 PM	#8
StephenDone Scooby Newbie Member#: 17994 Join Date: Apr 2002 Location: England (UK) Vehicle: 99 Impreza UKTurbo Midnight Blue	Values of 4 and upwards generally indicate a happy state of tune and keeping a nice saftey cushion for conditions such as heat soak of the TMIC.

11-05-2002, 10:18 PM	#9
Jon [in CT] * Banned * Member#: 2992 Join Date: Nov 2000 Chapter/Region: NESIC Location: Connecticut, USA Vehicle: 02 WRX Sedan Silver	I have seen logs where knock correction was as high as +10.5 at 6800 RPM under WOT in 2nd. In retrospect, probably any positive knock correction should be viewed as "good."

11-05-2002, 10:50 PM	#10
Gaspipe Scooby Newbie Member#: 16897 Join Date: Mar 2002 Location: Counce, TN Vehicle: 2002 WRX WRB	S.D. & Jon: I was somewhat stuck trying to figure out the KC values. The D.D. software is proving to be a pretty nice tool as I learn to actually decipher the data. Anyhow, thanks!