Shift cut settings - bike engined car

This section is dedicated to discussion of DTA engine control units such as the DTA E48 EXP, P8 Pro, DTA S40, S60, S80, and S100, as well as all things ECU related.
Rob Stevens
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Re: Shift cut settings - bike engined car

Post by Rob Stevens »

John has proper sensor so a non issue in this case
John Loudon
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Joined: Mon Jul 20, 2020 3:47 am
ECU Model: S100 Pro

Re: Shift cut settings - bike engined car

Post by John Loudon »

Thanks but the gear pot is not in question. It is the correct type for closed loop. My only concern is the settings
Rob Stevens
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Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Shift cut settings - bike engined car

Post by Rob Stevens »

Do a screen dump of all of them for a sanity check, photo is rubbish
John Loudon
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Joined: Mon Jul 20, 2020 3:47 am
ECU Model: S100 Pro

Re: Shift cut settings - bike engined car

Post by John Loudon »

Here you go Rob.

The first image is as the settings were with shift problems (40 deg retard)

The last 2 are my settings as they are now (untried) but with more retard and different chart settings

Thanks

John
Attachments
Shift_cut original.png
Shift_cut2.png
Shift_cut1.png
Alex DTA
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Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: Shift cut settings - bike engined car

Post by Alex DTA »

katana wrote: Sat May 07, 2022 11:24 am
Alex DTA wrote: Sat May 07, 2022 2:11 am
David Ferguson wrote: Fri May 06, 2022 5:02 pm Since the Suzuki K8 has a gear position switch (not a variable pot), there might be an issue when you are between gears - it other words it might stop the cut too soon. So, I would consider unchecking "use switch to start, pot to finish".
If that's the case, then that set up cannot be used for paddle shift. The ECU needs to see the voltage change to initiate the cut/retard strategy.
If the K8 GPS is like the Hayabusa one, it should provide what Alex says is a requirement. Switch has 5v In, Ground and different fixed voltage output subject to each gear eg. 1st = 0.75v, N = 1.2v, 2nd = 1.8v, 3rd = 2.5v, 4th = 3.2v, 5th = 3.9v and 6th = 4.7v (voltages are hypothetical for the example)
Even if the DTA is looking for a 'change,' doesn't the null time between gears count as a 'voltage change' as volts will drop to 0v between outputs.
No, that won't work.
If the shift cut start point is 30 mV, and a gear is at 1000 mV, then the shift cut will activate when the voltage goes above 1030 mV. Going to zero will not trigger the shift.
Alex DTA
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Re: Shift cut settings - bike engined car

Post by Alex DTA »

John Loudon wrote: Sun May 08, 2022 6:07 am Here you go Rob.

The first image is as the settings were with shift problems (40 deg retard)

The last 2 are my settings as they are now (untried) but with more retard and different chart settings

Thanks

John
Reduce the shift cut start point, 65 mV is probably too high. In the higher gears the barrel may not move enough to trigger the shift due to the load.
Reduce the gear filter value. 4 should be sufficient.
You have throttle blip enabled. You shouldn't do that here, you should have that set up in the paddle shift.
I would also try with zero ramp in time on the initiation. There are very few engine that require that. While yours does meet most of the criteria, it could also be hampering the shift.
Rob Stevens
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Re: Shift cut settings - bike engined car

Post by Rob Stevens »

To find the best triger point I do the following.
Put the car in say 3rd gear, engine off. And pull the car backwards to load up the dogs just like it's running hard, then operate the gear leaver gently to change up whilst viewing the pot voltage, this will help you understand how much the barrel rotates before all the slop in the selector forks is removed. You should do this for all gears, then select you cut point to be a little less than the lowest reading you get.
Rob Stevens
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Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Shift cut settings - bike engined car

Post by Rob Stevens »

Also I recomend setting the gear position voltages with the engine running to be as accurate as possible
John Loudon
Posts: 29
Joined: Mon Jul 20, 2020 3:47 am
ECU Model: S100 Pro

Re: Shift cut settings - bike engined car

Post by John Loudon »

Thanks Alex and Rob. Will give it a go
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