Sur-Ron w Teznic BAC4000. Tuning with an app…

[BriansEV]

I’m not sure if this is the place to post this but I figure there are others out there dealing with this same thing…
Hoping for some “collaboration”
(This is specific to the Sur-Ron Teznic BAC4000 kit that is tuned/flashed with an app Teznic provides)
I installed the BAC4000 and flashed to my config with the app (60v bypass, stock throttle all else default).
So by default I’ve been running zero phase amps since I installed the BAC4000 a week ago.
It had crazy torque but a very “non-linear” throttle.
Controller never cut out.
After the app update last night (02-18-22) I started increasing the new “initial torque” slider option.
The throttle did feel different but the controller would cut out (accel hard then die).
I had to reflash to get it back (sometimes a power cycle would do it).
I contacted Teznic, he opened a text string with me almost right away suggesting things to try.
Currently I’m at 200 phase amps, 20 initial torque.
Bike feels great at first but still cuts out at the top.
Power cycle gets it back now at least.

He said there’s a sweet spot with the 2 settings.

I’ll do more “tuning” tomorrow.
I got tired of doing hard pull runs up and down my street only to have it cut out on me at the top.
Plus the neighbors were starting to give the WTF eye.

so..anyone else tuned with the Teznic app?

FYI-
2021 Sur-Ron
BAC 4000 (Teznic)
60v batt bypass
Stock throttle
2.75 Shinkos
Dedicated Galaxy S8 / android 9 for dash app

 

[X-Nitro]

I think the asi controllers cut out so they don't do this, there are at least two more asi fire videos I've seen online.
https://www.youtube.com/watch?v=2JOxeeE_jmM

 

[MrBrownStone1]

Same problem here , just recent purchase with that controller from Teznic , complete mirror of your situation but does it with a bypass battery and the aftermarket pack 60v 50ah. Guy told me it was a thermal cut off for when its to cold ?? It was 4c last night and did some testing with both packs,, same cut off spot right at wot, if i then let off it resets itself, i was thinking hall sensor need some warmer weather to see if this cold thing is a thing.

 

[MrBrownStone1]

Hey Brian I came across another post with the same issue we are having. The guys throttle was shooting out 5.7 volts at full throttle causing it to cut. The bac4000 has a voltage spectrum and if its to high on wot it will cut the power as a failsafe. His solution was to get i to the bac4000 and increase the full throttle to 6v

 

[BriansEV]

Interesting. I’ll reach out to teznic, forward them this string and see if they can add that adjustment to the app…or “remote in” and do it.

 

[MrBrownStone1]

Good morning Brian, is it possible the tune is drawing to much from the packs causing it to go into LVC? like i said ive tested 2 packs and each do the same thing, If I ease into the throttle it will climb up but if i slam it wide open she shuts down then resets in like 2 secs. I also am running a CA for display and control so I can see the huge voltage sag on the display when she cuts out its low 50's . Again maybe these tunes are only good for a 2 sec burst wide open? can the tune govern that down so she wont cut out?

 

[BriansEV]

So I tried the new app update and had some better results. I’m not sure if my current “settings” are appropriate but I’m at like 50 initial torque, 550 phase amps. I set my wheel size and sprocket too (newly added app settings). I can rip on it WOT with no cut out and it has all the low end I need. I’m happy now. 

btw - this string is also over on the Luna electricbike forum…