two wideband sensors with significantly different afr's

Discuss which Sensors work best with these ECUs and share how you are using inputs and outputs
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bmwe36m3
Posts: 34
Joined: Thu Jan 28, 2016 5:51 am
ECU Model: S100 Pro

two wideband sensors with significantly different afr's

Post by bmwe36m3 »

Our bmw e36 race car has a bmw s65 engine with two aem bosch lsu4.2 sensors (one in each bank) of the v8 engine. We run the dta s100 in open loop and are getting afr's of 12.0 to 12.9 in the left bank and weird 14.0-16.0 in the right bank. I have swapped the sensors from side to side and still get similar results on the right bank. All the spark plugs look similar without any indication of a lean condition on either bank. We wired both sensors through the dta s100 and send the right bank data to the dash2pro using can data from the dta unit and the left bank data is hard wired from the dta s100 to the dash2pro. My understand was that the dta s100 unit software did not have the capability to send two widwband sensor data streams through can data.

What could cause such different results, and any ideas on a work around?
Alex DTA
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Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: two wideband sensors with significantly different afr's

Post by Alex DTA »

The latest firmware will give you both lambda values on the CAN stream.

If both sensors read the same, then you do have different AFRs bank to bank.
If you have turned on sequential injection, you can trim each cylinder to get the desired AFRs.
stevieturbo
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Location: Norn Iron

Re: two wideband sensors with significantly different afr's

Post by stevieturbo »

Can you install both sensors into the same exhaust pipe for a confirmation that way ?

I wouldnt expect both banks to read identical, but that sounds like a huge variation.

As the DTA receives analogue inputs from these widebands....is there a scaling for each input, or are both forced to use the same sensor scaling ( while both should read the same....they may not )
bmwe36m3
Posts: 34
Joined: Thu Jan 28, 2016 5:51 am
ECU Model: S100 Pro

Re: two wideband sensors with significantly different afr's

Post by bmwe36m3 »

Hi Alex,
I am not very technical regarding computers and I have never upgraded the firmware so I am interested in how difficult it is to upgrade. Is this something you could do remotely and connect to my laptop and update or do I need to send the unit back to the UK.
Ralph
stevieturbo
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Re: two wideband sensors with significantly different afr's

Post by stevieturbo »

Alex DTA
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ECU Model: S40 Pro
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Re: two wideband sensors with significantly different afr's

Post by Alex DTA »

Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: two wideband sensors with significantly different afr's

Post by Alex DTA »

stevieturbo wrote:As the DTA receives analogue inputs from these widebands....is there a scaling for each input, or are both forced to use the same sensor scaling ( while both should read the same....they may not )
No, we currently assume they are identical.
bmwe36m3
Posts: 34
Joined: Thu Jan 28, 2016 5:51 am
ECU Model: S100 Pro

Re: two wideband sensors with significantly different afr's

Post by bmwe36m3 »

Thanks to both Alex and Stevie for the assistance. I will try to update this evening.
Ralph
katana
Posts: 455
Joined: Sun Jan 27, 2013 6:08 pm
ECU Model: S60 Pro
Firmware Version: 29

Re: two wideband sensors with significantly different afr's

Post by katana »

Do they both run through controllers? Have the baseline / open air calibrations been done on both?
14 - 16 swing is more than the other bank which you've indicated as about 0.9! If you've only swapped sensors then the problem could be with the controller hence the calibration Q?
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