manual shift options?

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.
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Ap67et10
Posts: 42
Joined: Tue May 13, 2014 12:06 am

manual shift options?

Post by Ap67et10 »

After getting this Ford 4R75W trans working pretty well, I have started to lean on it a little harder to see how it performs. On my truck I currently have a Lokar shifter setup and no electric shift buttons yet. I do plan on creating some sort of shift paddles/buttons down the road, but I would like the shifter to function more like a manual shift would also. Is that possible? does it already do this? I read through a bunch of docs but didn't see anything specifically. I saw the burnout mode you recently added and it looks to be closer to what I would like.

My thought is that when O/D is disabled (I am using ground button input) the manual lever position should function the same as shift buttons would. I want it to be a true manual mode and downshift when I pull the lever into 2nd or 1st and not shift until I shift (unless above X rpm or whatever.) It kind of acts like a true manual input when I manually shift at times, and other times it doesn't seem to function like one. I haven't spent enough time on it to see if I have an issue somewhere if it really isn't set up to function like I was wanting/expecting.

Also....mostly unrelated. I got the TCC operating correctly now. I put a new range sensor in and that has cleaned up most of my random weird intermittent issues, which I suspected was a crappy input on the manual gear input.

I plan to update to 5.0x this week and play with some of the extra features.



Andrew
gui67
Posts: 134
Joined: Tue Oct 05, 2010 11:58 am
Location: Strasbourg, France

Re: manual shift options?

Post by gui67 »

You could maybe use 2 different shift table, one standard in O/D mode.
And with the O/D mode disabled, put target gear =4 everywhere, so the transmission will shift to the higher gear available: the one allowed by the lever.
Ap67et10
Posts: 42
Joined: Tue May 13, 2014 12:06 am

Re: manual shift options?

Post by Ap67et10 »

I posted this in my other thread....I have found a way to have quite a few.

Anyways, I loaded new firmware and found the manual shifting is functioning more like I expected however I found an issue I began having. When accelerating I had let off the throttle some as I shifted from 1st to 2nd, then I left it in 2nd for longer than I normally would and then continued to accelerate after I waited for traffic to clear. Once I accelerated to about 4500 rpm in 2nd I shifted to D and it stayed in 2nd. I decided to shift to neutral to see if it would reset itself and it shifted to neutral, but when shifted back to D it just felt like neutral still. I had to pull over and cycle the shifter to P and back to D to then get the trans to reengage again.

Also, I found once I run through the gears (1st and then shift the shifter to 2nd and then to D) it would function correctly, but then wont downshift anymore. Its as if it only functions 1 time then has to be cycled to P and then back to D to work again. Any reason this would happen? I would like the shifter to just function like an old school transmission does with a ratchet shifter or something, but it just keeps giving me issues. Any thoughts???


Andrew
Ap67et10
Posts: 42
Joined: Tue May 13, 2014 12:06 am

Re: manual shift options?

Post by Ap67et10 »

gui67 wrote:You could maybe use 2 different shift table, one standard in O/D mode.
And with the O/D mode disabled, put target gear =4 everywhere, so the transmission will shift to the higher gear available: the one allowed by the lever.

yes I plan to use the O/D button to activate two different tables, one very conservative and the other more aggressive. However I still would like to be able to pull the shift lever into 2nd or 1st and have it downshift and hold those gears until I move the lever again like an older non-electronic transmission would do. I don't mind if it down shifts to 1st when I have it in 2nd, which is exactly what an older transmission would do, I just want it to downshift to the gear I tell it to, if I tell it to do so by moving the shift lever.



Andrew
gui67
Posts: 134
Joined: Tue Oct 05, 2010 11:58 am
Location: Strasbourg, France

Re: manual shift options?

Post by gui67 »

Isn't it what the mshift is doing?
when I put the lever in 2nd it will only shift between 1 and 2, and never go in 3rd or 4th, whatever I do.
same for 3rd: 1, 2 or 3, never in OD. Or did I not understand what you want to do?
Ap67et10
Posts: 42
Joined: Tue May 13, 2014 12:06 am

Re: manual shift options?

Post by Ap67et10 »

Yes you are correct. I found that it was not behaving correctly for other reasons. I got those sorted out and now it seems to be working as I would expect. I've had a few kinks I've been sorting out on my setup, and those kinks have had some unwanted/unexpected results. The way the manual gear selection was operating at the time was one of those unexpected results.


Andrew
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