Gm 90- 75 speedo settings

[kev kirk]

I am trying to understand the different settings available, when to change them and their effect.
I have written the list below stating my thoughts and would like others to fill in my blanks (?) and answer the few questions i have posed.
I am sure that the more answers i get the more questions i will need to ask.

1. Voltage cut off:
The minimum voltage that the lipo can reach before the speedo cuts power to the motor.
Use: Lipo battery protection
2. Start Amp

The max amp used at full throttle after the stick has been in neutral for more than 3 seconds.
Use: Prevent too much wheel spin at start of the race
3. Amp limit

The max amps the motor can draw at any one time during the race (except start and full throttle).

Use: Used to limit punch
Prevent too much wheel spin under hard acceleration
Helpful in the wet.
4. Turbo (A/ms)

The rate of Amp increase available for every 4 milliseconds after full throttle has been reached. Only works once until neutral is selected, then will be used again.

Use Increase top speed at full throttle

Q: How long does neutral need to be selected to reset the Turbo function?

5. Soft Start
The amount of time the motor will take to reach full speed (ramp time)

Use To control punch (acceleration rate)

Q: Is this better to use to limit punch or the amp limit, (time would be more consistent than amps, but would not be grip dependant)

6. Automatic throttle
Sets the neutral throttle setting from 0 to +. Could be termed as tickover or motor speed when the stick is in neutral.
Use (maybe for planes)

7. Frequency
Pulse frequency of the speed controller.
8. RPM Limit
Sets the max rpm of the motor
Use Controlled racing event or beginners training
9. PMW Start
Sensor less motors only
10. Lim Start
Sensor less motors only
11. Switching point RPM
Rpm level where high speed timing increases start.
Use: Give more throttle control at lower rpm?
12. Power curve
Pre-set power curves
13. Timing with sensors
Sets the initial motor timing
Use: Increase the initial motor timing the same as rotating the end bell.
14. Fixed timing
?
15. Timing 1
?
16. Timing 2
?
17. Minimal timing time
?
18. Timing up to special settings upto 30°
?
19. Timing 1 upto max timing
?
20. Reserved 2
?
21. Variable dependence timing
?
22. Add timing only at full throttle
Adds additional timing only when stick at full throttle
Use: Would only add timing on the straight
23. Timing software 7.1
?

[dale]

Fixed timing is the main setting used to adjust your overall maximum timing. Turn it up for more speed, turn it down to reduce heat.

The switchpoint allows you to have maximum torque at low revs (i.e. out of slow corners), and also reduces heat. I definitely recommend using this. I run 15k for 10.5T, 10-12k would be about right for 13.5T.

Variable dependence timing means that the timing given to the motor is proportional to the throttle position. So if you set Fixed Timing to 24deg then at full throttle you will have 24deg timing, and at half throttle you will have 12deg timing. I recommend using this, it will reduce heat and make things smoother.

Items 15, 16, 17, 18, 19, 20 and 23 are not used from v13 firmware onwards, so you can ignore these.

I have sent you a PM with a link to a full guide for the GM settings written by top GM man Martin Hoffer.

[kev kirk]

Hi dale
Thanks for the reply.
Would the variable dependence timing only start at the switch point?
Also what settings are the best to tame the motor? our local track (outdoor) is very slippery and my thumb very thick
Cheers
Kevin

[Chris ODonoghue]

if you want to reduce punch, reduce frequency (try 4khz) and then reduce start amps, you don't say what motor you're running and in what application ? (I'm assuming TC? )

[kev kirk]

Hi Chris
Yes I run in 10.5 TC. I normally run a gm 10.5 pro motor but recently changed to a teampowers which runs very hot compared to the gm. This has got me messing with settings and I realised I did not fully understand them all
Cheers
Kevin

[Chris ODonoghue]

14. Fixed timing <-- more timing/power when using high speed timing (HST)
15. Timing 1 <-- only used when running old style timing, n/a when using HST
16. Timing 2 <-- same as timing 1, n/a when HST
17. Minimal timing time <-- very useful to control temps, effectively limits timing at full throttle so as to keep motor cooler?
18. Timing up to special settings upto 30° <-- n/a when HST
19. Timing 1 upto max timing <-- n/a when HST
20. Reserved 2 <-- option list for the type of timing
21. Variable dependence timing <-- apply timing based on where throttle stick is?
22. Add timing only at full throttle <-- as it says
23. Timing software 7.1 <-- use old style timing with timing 1/2 ramps instead of HST

[kev kirk]

Chris
Have you ever adjusted the soft start settings?
Cheers
Kevin

[Chris ODonoghue]

Only if I have problems when running sensorless telly, not something I change otherwise

[kev kirk]

Hi Chris
What changes would you recommend for driving in the wet? I was thinking of lifting the switching point to 15000. Anything else you can recommend?
Cheers Kevin

[Chris ODonoghue]

Personally I don't change anything in the wet, so probably not the best person to ask mate, sorry. I run mine the same wet or dry!