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Offline Belco100

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Re: Decat pipe
« Reply #20 on: June 18, 2018, 01:58:12 PM »
Someone put up a video on Brock's Performance for a GSXR1000. I think it was about 4 or five videos in Brock talks about the 02 sensors and says they are mostly there for emissions and always removes them.

Well worth watching them all.

Offline bazzer

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Re: Decat pipe
« Reply #21 on: June 18, 2018, 02:00:55 PM »
They are generally there to make sure the cat works well. Too rich or lean and the cat works very poorly and it can be damaged.

Most engines at wide open throttle turn off the lamda correction, its generally used at light throttle and cruise.



Offline Patrick Bateman

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Re: Decat pipe
« Reply #22 on: June 19, 2018, 03:59:33 AM »
It's been a slow day at work so I've been hunting down info on O2 sensor removal for the XR... whilst I can't find anything specific, if the O2 sensors are removed from the 2014 RR, it will NOT log any codes or change performance (people have tested this on a dyno) but it does log a fault in the ECU that can be seen with a Hextool or BMW scanner - just like the EXUP valve cables. Whether this applies to the XR I couldn't say - but I am meeting up with a Hextool owner shortly so I will unplug the sensors and find out.


As for O2 sensors themselves, there is quite a bit of misinformation out there so here is the spiel I give my students.

The balance between rich and lean air/fuel mixtures known as stoichiometric - the perfect balance of air and fuel that results on complete combustion. This will vary depending on the type of fuel used, but for petrol the stoichiometric value is generally 14.7 parts air and 1 part fuel. Anything more is lean, anything less is rich.

In operation, an O2 sensor compares the oxygen content in the exhaust gas against a reference value of the oxygen content in the atmosphere. When the detected level of oxygen is high, this means that combustion has been incomplete and the air/fuel ratio is lean (higher than 14.7:1). When the detected level of oxygen is low, this means that combustion has consumed it all, indicating the air/fuel mixture is rich (lower than 14.7:1). The O2 sensor can only measure either rich or lean mixtures over a small range - this is why they are referred to as narrow band sensors - but they are not designed to measure whether the mixture is stoichiometric. This is why autotune systems that use an O2 sensor are useless.

A signal from the O2 sensors is only used to trim mixtures when load and throttle position are low, known as closed loop - where the ECU is in a continuous loop or measure-adjust-measure-adjust-measure-adjust and so on FOR EMISSIONS PURPOSES ONLY. When load and throttle position exceed target values, the ECU goes into open loop, where it relies on the fuel table mapping to determine fuel quantity.

Most modern cars will also have an Air-Fuel ratio sensor mounted after the catalytic converter that measures its performance FOR EMISSIONS PURPOSES ONLY. This sensor produces an accurate signal over a wide range between rich and lean - this is why it is referred to as a wide band sensor - but you won't see one fitted to a motorcycle (yet) as the emissions requirements do not make it necessary.

Tuners use wide band sensors to determine the air/fuel ratio during fuel map adjustment on a Power Commander, flash tune, etc. They can place the engine under any RPM and load with a dyno, then inspect/adjust the fuel quantity as necessary
I need to return some videotapes.

Offline Patrick Bateman

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Re: Decat pipe
« Reply #23 on: June 19, 2018, 04:05:10 AM »
Also, I search high and low for "O2 Sensor Eliminators" for the S1000RR/R/XR and found nothing. This might confirm the sensors can be unplugged without any repercussions. They are available most other popular sports bikes though! The eliminator is primarily a resistor that tricks the ECU into thinking that the sensor is still connected - most ECUs will perform an self test on startup and if there is no load on the O2 sensor heater circuit they start chucking codes
I need to return some videotapes.

Offline Garbo

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Re: Decat pipe
« Reply #24 on: June 19, 2018, 06:43:09 AM »
I have found with headers and no fuelling module the bike rides a bit cranky around town. Didn’t get the XR for commuting so very happy 😊
Still deciding whether to get the rapidbike module 🧐

Offline smithy

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Re: Decat pipe
« Reply #25 on: June 19, 2018, 06:47:33 AM »
*Originally Posted by Garbo [+]
I have found with headers and no fuelling module the bike rides a bit cranky around town. Didn’t get the XR for commuting so very happy 😊
Still deciding whether to get the rapidbike module 🧐

I hope to be able to fit my Arrow headers this coming weekend....then I'll get the Rapid Bike EVO to do it's "auto-tune" function...will be interesting to see how good it is compared to a proper dyno setup.

Smithy.

« Last Edit: June 19, 2018, 06:49:20 AM by smithy »
When I die, I want to go peacefully in my sleep like my Grandfather....not screaming like the passengers in his car..!

Offline Patrick Bateman

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Re: Decat pipe
« Reply #26 on: June 19, 2018, 07:02:00 AM »
Please don't.

A factory O2 sensor is only good for reading either a rich or lean condition - not a stoichiometric condition. There is not a dyno operator on the planet that uses a narrowband O2 sensor to tune engine management - so what makes you think Rapidbike have magically found a way of doing so?

I have worked with engine management for many years now and seen many people get lesser results than what they paid for.
A PCV + tuning is the proper solution. An O2 sensor is an emission control device.
I need to return some videotapes.

Offline bazzer

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Re: Decat pipe
« Reply #27 on: June 19, 2018, 07:21:24 AM »
Patrick, doesn't the Rapid bike Evo use a wideband sensor? If not then I agree with you :-)


Offline Patrick Bateman

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Re: Decat pipe
« Reply #28 on: June 19, 2018, 07:28:20 AM »
The Rapidbike website says they use the factory sensor - and as far as I know, the factory sensor is O2 (narrowband), not Air/Fuel (wideband)
I need to return some videotapes.

Offline bazzer

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Re: Decat pipe
« Reply #29 on: June 19, 2018, 07:35:44 AM »
That's interesting, a lot of them replace with a wideband and provide a faked narrow band output for the ECU. If its using a standard narrow band then it is indeed rubbish.


 


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