Author Topic: Acceleration enrichment parameters in MT  (Read 19024 times)

Offline rob@vems.co.uk

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Re: Acceleration enrichment parameters in MT
« Reply #15 on: July 11, 2007, 09:12:46 am »
TPS is flickering?

What age/serial number is your board?

Offline Denmark

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Re: Acceleration enrichment parameters in MT
« Reply #16 on: July 11, 2007, 01:46:51 pm »
I can only see the flickering, becourse that the megatune gauge changes color, from white to yellow, as it keeps stable on 1%,
But it is the same time that it changes color, that it but in the accel enrichment.

Of the top of my head, it´s board number 594 , or just about there, as i got 6 when i ordered the bunch

/Skassa
working on the boxer

Offline cliffb75

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Re: Acceleration enrichment parameters in MT
« Reply #17 on: July 11, 2007, 06:25:38 pm »
I've seen this on other vehicles. It was just play / wear in the sensor itself, but it had exactly the effect you describe of introducing transient comp on a nominally steady throttle.

If you can calibrate around it then great. In our case we switched to MAP triggering and were able to calibrate that to an acceptable level instead.

Offline rob@vems.co.uk

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Re: Acceleration enrichment parameters in MT
« Reply #18 on: July 17, 2007, 09:41:46 pm »
Just a quick note to keep you all informed, I'm just about to have a little test of a new version of Firmware that has faster reacting accel enrichment with a smooth decay.  The duration scaling will be address soon, once its been decided how RPM and MAP based scaling should work best.

Rob

Offline dnb

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Re: Acceleration enrichment parameters in MT
« Reply #19 on: July 17, 2007, 10:23:25 pm »
I saw that on the WIKI.  Was tempted to give it a go, but Nic's having the Griff tomorrow.

Offline dnb

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Re: Acceleration enrichment parameters in MT
« Reply #20 on: July 17, 2007, 10:41:56 pm »
Here's a section of datalog from me gently "making progress" down a bit of dual carriage way.



pulse width (PW) and lambda are on the right hand axis.

You can estimate transit time from this graph based on the time it takes for the lambda to register the pulsewidth has dropped to zero.  (RPM isn't shown, but transit time is proportional to this too...)  You can then see the leaning out of lambda (slightly) on acceleration - this is the error from having too little acceleration enrichment.


Offline cliffb75

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Re: Acceleration enrichment parameters in MT
« Reply #21 on: July 17, 2007, 10:56:38 pm »
That'll work  :)

Not quite as accurate as Fuelling steps at fixed airflow, but close enough to get the idea.

Your lamda scaling is a bit iffy - try doing a *10 line (i.e. 10=lambda 1) if you have to use excel so that you get the resolution where you want it.

At first glance, looks like you can aford to be a bit more agressive there as you don't seem to have any rich dip at all