Selective clutch for when engaging TCC

A forum for discussing applications and implementations of the MegaShift transmission controller code for the GPIO from B&G. This can control up to 8-speeds and 6 shift solenoids (plus a 16x9 table for controlling a PWM line pressure valve). It has manual and fully automatic modes (16x9 load x speed table), with under and over rev-limit protection, and full data logging of all inputs and outputs (among many other abilities). A TransStim to test your completed board is also available.
Addicted
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Location: Winchester, England

Selective clutch for when engaging TCC

Post by Addicted »

Lance,

At this point the only functionality that the VW/Audi audi transmission requires thats not in the software is the ability to activate the upshift selective clutch when TCC is being engaged.

I'm currently doing this using an Arduino, it monitors the TCC solenoid transistor and when it sees it go high it activates the Upshift solenoid transistor for a few milliseconds.

This works OK for me, but I know that there are a few people watching my progress before implementing Megashift on thier own VW/Audi transmission for whom the Arduino is probably not the best solution.

Whats the feasibility of adding "Engaging TCC" to the selective clutch menu/functionality after "upshift to fourth" etc.. (I realise adding it the menu in TS is the easy part!)

Martin
Bernard Fife
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Re: Selective clutch for when engaging TCC

Post by Bernard Fife »

Martin,

This should be 'doable'. Once we have the hysteresis working (hopefully very soon) I will look at adding that ability asap.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Addicted
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Joined: Mon Oct 14, 2013 7:14 am
Location: Winchester, England

Re: Selective clutch for when engaging TCC

Post by Addicted »

Hello Lance,

Have you had the opertunity to look at this? :)

It appears my slipping transmission is because I've blown the seals on the TCC valve, probably caused by engaging TCC at high line pressure..

Martin
Bernard Fife
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Joined: Fri Apr 04, 2008 1:28 pm

Re: Selective clutch for when engaging TCC

Post by Bernard Fife »

Martin,

That's too bad about the TCC valve. I haven't looked at the added function yet, but will shortly.

I may come back to you for more information as I try to implement this, as I am not 100% sure on how you want this to work. If you have any documents or information on exactly how this is done in an OEM settings, as well as how you want it to work in MShift. My thinking is that you want to engage the TCC when upshifting to 4th - is it that you *always* want to engage the TCC when upshifting to 4th, even if it wasn't engaged at the time of the initiation of the shift?

If that's so, it's probably easiest for me to add a option under 'TCC Settings -> TCC Control Limits -> TCC Application in highest gear' to 'ALWAYS apply TCC in high gear and shifts to high gear'.

I'll assume that's what you want and get to work on it. I'll post back here when I have something to test.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Addicted
Posts: 188
Joined: Mon Oct 14, 2013 7:14 am
Location: Winchester, England

Re: Selective clutch for when engaging TCC

Post by Addicted »

Hi Lance, if I get chance later I'll upload some data (going to be a bit busy removing the transmission! :D)

I have two selective clutches, 1 of which is activated on all downshifts AND when TCC is engaged. The OEM application simply treats the act of engaging TCC to be the same as a downshift. I suppose that because the TCC soleniod is on/off and not PWM the clutch is activated to soften the TCC engagement..

So in the menu where we choose when the selective clutchs are activated I would 'like' to see an option of 'engage TCC' added.
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Selective clutch for when engaging TCC

Post by Bernard Fife »

Addicted,

Okay, I see my interpretation above obviously wasn't right (the code already acts that way anyhow).

Is it that you want the spare port to activate *whenever* the TCC is active (as well as during the upshifts/downshifts)? Re-reading this thread, I think this is what you are asking for. If you could confirm this, it should be straightforward and I will get to work.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Selective clutch for when engaging TCC

Post by Bernard Fife »

Addicted,

Also, do you want the spare port to activate *whenever* the TCC is active (as well as during the upshifts/downshifts) OR just for a set period of time after the TCC activates (i.e. "monitor the TCC solenoid transistor and when it goes high activate the Upshift solenoid for a few milliseconds")?

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Addicted
Posts: 188
Joined: Mon Oct 14, 2013 7:14 am
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Re: Selective clutch for when engaging TCC

Post by Addicted »

Lance,

Attached is a much edited example of the datalogs I took from the factory TCU. Open it with Excel NOT Megalogviewer!

Hopefully its pretty self explanatory, you can see how SP1 is activated for all downshifts, but also when TCC is engaged in third gear.

For the shift from 3 to 4 I can already select SP1 to activate in Tunerstudio, I'd just like to be able to mimic how SP1 is activated as TCC is engaged in third.

Martin

edit: I only want the SP1 to be active for a moment, about as long as a normal shift completion. You can see on the datalog that its only active for a few milliseconds..
Attachments
bosch_tcu.msl
(93.5 KiB) Downloaded 667 times
Bernard Fife
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Re: Selective clutch for when engaging TCC

Post by Bernard Fife »

Martin,

Okay, thanks for that. It looks like sp1 is driving the N94 solenoid. And it's activated during downshifts to 2nd and 3rd and upshifts to 4th (and this is handled by the current code); but also N94 is activated whenever the TCC is initially engaged (but only in 3rd gear).

I could add an option for the spare port (when in selective clutch mode) to engage in user set gear(s) when the TCC is engaged, with an user setting for the activation duration time (in milliseconds - say from 0.008 sec to 2.000 sec, in 8 msec steps). From you log, it looks like the duration is about one second or a bit more (from the middle of 15:51:45 to the middle of 15:51:46), so I'll set the default duration to 1.000.

It would make sense to do this for both sp1 and sp2, so I will do that. I'll call it "TCC_follow_mode".

This would be under a separate menu (because we would have up to 8 gears to set [but just one for you], plus the time period setting, so the existing menu could get very crowded). The menu will be right under the 'Clutch Pattern (SP2/Output4)' listing, and will only be accessible when selective clutch mode is enabled.

Does that work for you?

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Addicted
Posts: 188
Joined: Mon Oct 14, 2013 7:14 am
Location: Winchester, England

Re: Selective clutch for when engaging TCC

Post by Addicted »

Lance wrote:Martin,

but also N94 is activated whenever the TCC is initially engaged (but only in 3rd gear).
These are the words I was looking for when I was trying to explain the function ;) So the fact that you've done a better job of putting it into words than me would suggest you understand what I'm after!
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