Blackthou

Nitrous
Joined
Nov 26, 2014
Messages
1,365
Location
Essex UK
Ride
2014 Black 'n' Red R3R. RamAir, Tors, DP Link pipe
Hi,

I'm seeking opinions on the above. I'm running RamAir, Tors and DP Crossover. I have the O2 sensor turned off in software, removed and plugged following suggestions that if it is left in place and remmed out it gets fried.

Questions are:

Why is it necessary to remove / disconnect the sensor when the purpose of it is to provide a closed loop feed back? Does it try then to correct the tune and in effect negate it.

Is there an alternative O2 sensor that does not react in the same way?
 
Its simple look at the fuel ratio in the narrow band area you either have to change them or disconnect it. You can go wide band but you will need to get some real tuning software not free hackware.
 
:)First off, why it's best to remove it: They are a sensitive device, the temperature is controlled to be in a narrow window for max life span, moisture is the devil for O2 sensors and it's disabled in software and left in the bike moisture can kill it.

Second, as to why it's better turned off: Triumph tunes only use it at low RPM low opening, and they shoot for a 14.3ish AFR, nothing wrong with that to be honest. Read on how narrow and sensors work, they don't measure the afr, they count how many " too rich" or "too lean" incidents it has over a time span and add or remove fuel to compensate. The result is an engine that's never right, instead it swings back and forth across the target lean to rich, but never right.

The range of the swing depends upon how fast the ECU updates the sensor value and does the man. The rocket ECU does both sampling and math pretty slowly, the result is a chunk chunk chunk idle, when you turn it off and set the AFR slightly "too rich" in the mid to high 13:1 range idle will be dead steady and stable.

Additionally if you were to make changes in your F and L tables, and the sensor is turned on but you don't change the AFR target to deactivate closed loop, it'll slowly trim both short and long term trims. The problem with that is that those trims are not limited to the closed loop areas but are instead applied elsewhere in the map too. It effectively undoes any custom ECU work you have.

Add in a PC-V and then there's another layer of computer fighting the ECU which is already fighting the work you've done.

Hope that clarifies your conundrum :)

PS: The long and short term trim issue is why installing a PC-V using their simulator instead of disabling the sensor in TuneECU is a mistake.
 
@Claviger and @HansO please explain further for my and others complete ignorance!

How does this relate to the Dynojet AT200 and PCV with a HansO tune I have in my '10 Roadster? I understand that the AT200 replacement O2 sensor is wideband and you can set the sampling from 5-20 seconds, I believe HansO leaves it at 20seconds. This AT200 O2 sensor also provides info to the Dynojet POD LCD display doesn't it?
 
Different animal, it's a wideband, as such it's counting the amount of O2 in the exhaust instead of just too rich/too lean. It then feeds that ratio to the PC-V which makes adjustments to correct fueling. The difference is the PC-V does it at an incredibly fast rate and has a much better algorithm to get close to target right away instead of swinging back and forth (though it still does a small amount if the initial fuel table value was way off).

That's essentially why you set the stock ECU to a fairly close to right base tune, and use the PC-V for fine tuning. It does it faster and better with more granularity and smaller fuel increments.

The 5-20 number is an enrichment/enleanment percent, how much fuel it can add or take from the mix. When developing a new tune I usually leave it at 20% for a couple days, cut it back to 10%, then 5%, then 3%. It still requires some manual table adjustments, but by the time it gets to 3% it's pretty much dead on.

If Triumph hadn't been cheapskates and used a wideband as OEM tuning R3s would be trivial as it would correct itself as you ride via trims.
 
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The optimal setup would be triple widebands, one per cylinder feeding an ECU directly, like a MOTEC or Microsquirt, that gives FULL control instead of about 40% control like TuneECU does, 6 injectors on 6 separate channels, 6 ignition circuits and the host of other advanced features OEMs feel are extraneous.
 
Thank you Mr Claviger. Is the PC-V the way to go then in preference to TuneECU? Does it interact still with the "map" or does it recompute and optimise it? I suppose that there's no real substitute for a professional and a dyno but am interested in learning.

Is there still a lean issue with TuneECU at higher revs or was the consensus that it wasn't after all?

Cheers
 
@Claviger

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Thank you Mr Claviger. Is the PC-V the way to go then in preference to TuneECU? Does it interact still with the "map" or does it recompute and optimise it? I suppose that there's no real substitute for a professional and a dyno but am interested in learning.

Is there still a lean issue with TuneECU at higher revs or was the consensus that it wasn't after all?

Cheers

PC-V works by taking the signal sent from the ECU, intercepting it, and adjusting it before it gets to the injector. The best solution hands down, is a fully done TuneBOY tune from one of the gurus. If it's a stock motor bike, TuneECU can give a really good result on it's own, if done by a good tuner. If you don't have one of the small handful of miracle workers who can TuneECU tune your bike near you, a good base TuneECU tune coupled with an "anymans" 13:1 AFR tune using a PC-V is also quite viable.
 
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