Mach-E GT acceleration modeling shows possible performance capability of the GT

I applied an acceleration model similar to the one for RWD and AWD ER
https://www.macheforum.com/site/threads/mach-e-extended-range-acceleration-modeling.2177/
to the Mach E GT (base) with the limited info available. See the attached pdf for details.
Many approximations, no fudging or tuning to match measured results.
Summary: (with 1 ft roll out time of 0.3 s subtracted)

Launch acceleration - 0.81 g
60 ft time - 1.87 s at 38.6 mph (just at combined motor base speed, and torque starting to drop)
0-60 mph - 3.5 s (note this the base GT, not GTPE)
50-70 time - 1.85 s
1/8 mile time - 7.7 s @ 94.1 mph
1/4 mile time 12.0 s @ 116 mph

Conclusions
These results show the possible performance capability of the GT. The assumed perfect launch from zero speed and extended constant power region above about 8 sec/ 1/8 mile / 90 mph are approximations that are probably not achievable. Hence the Ford quoted performance of 3.8 s. But, the GT should be capable of better 1/4 mile times than what has been measured and reported so far.


@phidauex do you have any data of front motor speed vs vehicle speed so we can determine the front motor gearing?

EVmodeler said:

I applied an acceleration model similar to the one for RWD and AWD ER
https://www.macheforum.com/site/threads/mach-e-extended-range-acceleration-modeling.2177/
to the Mach E GT (base) with the limited info available. See the attached pdf for details.
Many approximations, no fudging or tuning to match measured results.
Summary: (with 1 ft roll out time of 0.3 s subtracted)

Launch acceleration - 0.81 g
60 ft time - 1.87 s at 38.6 mph (just at combined motor base speed, and torque starting to drop)
0-60 mph - 3.5 s (note this the base GT, not GTPE)
50-70 time - 1.85 s
1/8 mile time - 7.7 s @ 94.1 mph
1/4 mile time 12.0 s @ 116 mph

Conclusions
These results show the possible performance capability of the GT. The assumed perfect launch from zero speed and extended constant power region above about 8 sec/ 1/8 mile / 90 mph are approximations that are probably not achievable. Hence the Ford quoted performance of 3.8 s. But, the GT should be capable of better 1/4 mile times than what has been measured and reported so far.


@phidauex do you have any data of front motor speed vs vehicle speed so we can determine the front motor gearing?

Click to expand...

Thanks for continuing to put in the work on this!
I think we’ve seen launch G close to/at 1 already, and therefore some 60Ft times in the 1.80 range iirc. And yeah, the 94 mph 1/8th and 116mph 1/4 mile trap speeds are probably fairy tales as you stated. But 91-92/110-112 should be non-fiction.

EVmodeler said:

@phidauex do you have any data of front motor speed vs vehicle speed so we can determine the front motor gearing?

Click to expand...

I took a look at my Premium AWD ER, and tried to validate the final drive ratios. I'd read that the rear ratio is 9.05, and the front is 10.0. From my drive data, this appears to be accurate if I assume a 97% tire diameter (accounting for a little wear or squish from inflation).

With these values I predict that at 60mph the rear motor should be at 6,556 RPM and the front would be at 7,245 RPM.



Since the GT has two of the same motor, and we've been told that it is the same as the rear motor on the other trims, then I think both motors on the GT and GT-PE have a 9.05 final drive ratio. That would explain the speed limiter too - at 124 mph you are running 13,550 RPM which is very close to the 13,800 redline.

Just curious - does your acceleration model account for rolling resistance and aerodynamic drag?

Yes, the gear ratios are known/published for the AWD motors.
The GT may have the same rotor and stator as the rear motor, but I am pretty sure the front motor is packaged differently (for example, no park pawl) and may have a different gear ratio? We just need someone with a GT to use your data tools to see. I did assume they are the same at 9.05. But note that the torque and power are not 2x the RWD/AWD ER rear motor, probably due to battery limitations.
Yes, the model includes rolling and aero drag (from the EPA road load ABCs) - see the AWD accel model for the detailed force balance that I did not repeat in this write up.
Thanks for the data confirmation.

phidauex said:

I took a look at my Premium AWD ER, and tried to validate the final drive ratios. I'd read that the rear ratio is 9.05, and the front is 10.0. From my drive data, this appears to be accurate if I assume a 97% tire diameter (accounting for a little wear or squish from inflation).

With these values I predict that at 60mph the rear motor should be at 6,556 RPM and the front would be at 7,245 RPM.

Since the GT has two of the same motor, and we've been told that it is the same as the rear motor on the other trims, then I think both motors on the GT and GT-PE have a 9.05 final drive ratio. That would explain the speed limiter too - at 124 mph you are running 13,550 RPM which is very close to the 13,800 redline.

Just curious - does your acceleration model account for rolling resistance and aerodynamic drag?

Click to expand...

EVmodeler said:

Yes, the gear ratios are known/published for the AWD motors.
The GT may have the same rotor and stator as the rear motor, but I am pretty sure the front motor is packaged differently (for example, no park pawl) and may have a different gear ratio? We just need someone with a GT to use your data tools to see. I did assume they are the same at 9.05. But note that the torque and power are not 2x the RWD/AWD ER rear motor, probably due to battery limitations.

Click to expand...

Good point, all we have to confirm that the front motor is the same as the rear is some fairly broad statements. Doesn't mean there weren't other changes like the gear ratio. I had assumed that the power limitations were due to the battery - even at 480hp the battery is running at almost 4C (accounting for some losses).

If anyone would like to collect data from the GT, it is quite easy. I recommend using the CarScanner Pro app for iOS devices (costs a few bucks, but it is worth it), and a compatible ELM327-type Bluetooth LTE ODB2 adapter (I have the Viecar Bluetooth v4.0, was ~$25).

You don't need to pair the devices (Bluetooth LTE is a simple beacon), and if you create a simple profile for your MachE (it is in the app already) and a simple dashboard with a few metrics like speed and motor RPM, and turn on the Data Logging feature, then it will automatically capture logs whenever you are connected.

The logs are a bit tricky to work with raw, but I've made some scripts to help clean them up and resample them to a clean 1 second interval. If anyone posts some raw logs I can help with them.

I did a few quick 0-60 pulls on my Premium AWD today, at only 66% SOC, but I did get some datalogs and graphs. They include some useful tidbits such as the RPM at which the torque curve starts to fall off, and the balance of power between front and rear. Hopefully it is of some use here! I need to find a place where I can safely do some faster runs to see how the Premium handles acelleration up to 100mph.

https://www.macheforum.com/site/threads/driving-dynamics-and-charging-data-files.8473/post-246236

phidauex said:

I took a look at my Premium AWD ER, and tried to validate the final drive ratios. I'd read that the rear ratio is 9.05, and the front is 10.0. From my drive data, this appears to be accurate if I assume a 97% tire diameter (accounting for a little wear or squish from inflation).

With these values I predict that at 60mph the rear motor should be at 6,556 RPM and the front would be at 7,245 RPM.

Since the GT has two of the same motor, and we've been told that it is the same as the rear motor on the other trims, then I think both motors on the GT and GT-PE have a 9.05 final drive ratio. That would explain the speed limiter too - at 124 mph you are running 13,550 RPM which is very close to the 13,800 redline.

Just curious - does your acceleration model account for rolling resistance and aerodynamic drag?

Click to expand...

Yes the spec sheets list those motors and 9.05 final drive for the GT.

harrysiii said:

Yes the spec sheets list those motors and 9.05 final drive for the GT.

Click to expand...

Excellent, thanks for the confirmation - I was pretty sure it was true but not completely sure!

Has anyone done electrical/telemetry analysis on the Mach-E?

I saw one for the ID.4 that measures cell voltages, rpm, current/amps

https://www.vwidtalk.com/threads/80...ed-2-5-mi-kwh-at-58-f-us-id-4-rwd-77kwh.1303/

The driver hard accelerated from 25mph to 80mph at 3500 seconds at that caused a massive voltage sag in the cells (down to 3.6v) - which means the ID.4 should not accelerate too far beyond that (in fact specs say max speed is 112mph). Peaks amps was 158A... total battery voltage sagged from 376v to 347v.

Li-ion cells under load dropping below 3.5v will cause damage (excessive heat first). The Battery IR of the ID.4 is the limiting factor of that car's performance... which can be solved by increasing battery capacity or using higher-quality li-ion cells. No amount of software would fix this issue.

Measuring the voltage drop in a Mach-E along with rpm + mph would prove that the car is capable of more.

voxel said:

Has anyone done electrical/telemetry analysis on the Mach-E?

I saw one for the ID.4 that measures cell voltages, rpm, current/amps

https://www.vwidtalk.com/threads/80...ed-2-5-mi-kwh-at-58-f-us-id-4-rwd-77kwh.1303/

The driver hard accelerated from 25mph to 80mph at 3500 seconds at that caused a massive voltage sag in the cells (down to 3.6v) - which means the ID.4 should not accelerate too far beyond that (in fact specs say max speed is 112mph). Peaks amps was 158A... total battery voltage sagged from 376v to 347v.

Li-ion cells under load dropping below 3.5v will cause damage (excessive heat first). The Battery IR of the ID.4 is the limiting factor of that car's performance... which can be solved by increasing battery capacity or using higher-quality li-ion cells. No amount of software would fix this issue.

Measuring the voltage drop in a Mach-E along with rpm + mph would prove that the car is capable of more.

Click to expand...

These are the kind of posts that make me sad.

They just remind us of the limitations of BEVs when compared to ICE.

I look forward to the day when it isn’t a compromise to make the switch. I hope I’m not jumping in too early.

Very interesting, I would like to see someone put on a set of lightweight 18" wheels and do a couple of runs VS the stock 20" and see what kind of a difference there is (if any)

tuminatr said:

Very interesting, I would like to see someone put on a set of lightweight 18" wheels and do a couple of runs VS the stock 20" and see what kind of a difference there is (if any)

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You physically cannot put 18" wheels over the brakes of the GT. 19" is doubtful as well.

Scooby24 said:

You physically cannot put 18" wheels over the brakes of the GT. 19" is doubtful as well.

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Well if someone lives in MN we can test fit

voxel said:

Has anyone done electrical/telemetry analysis on the Mach-E?

I saw one for the ID.4 that measures cell voltages, rpm, current/amps

https://www.vwidtalk.com/threads/80...ed-2-5-mi-kwh-at-58-f-us-id-4-rwd-77kwh.1303/

The driver hard accelerated from 25mph to 80mph at 3500 seconds at that caused a massive voltage sag in the cells (down to 3.6v) - which means the ID.4 should not accelerate too far beyond that (in fact specs say max speed is 112mph). Peaks amps was 158A... total battery voltage sagged from 376v to 347v.

Li-ion cells under load dropping below 3.5v will cause damage (excessive heat first). The Battery IR of the ID.4 is the limiting factor of that car's performance... which can be solved by increasing battery capacity or using higher-quality li-ion cells. No amount of software would fix this issue.

Measuring the voltage drop in a Mach-E along with rpm + mph would prove that the car is capable of more.

Click to expand...

Such extensive telemetry can be done in MME with Car Scanner app, Phidauex already posted several charts and data sets.

It would be interesting to log the average module voltage and minimum module voltage under continuous max load in Car Scanner, to see how low the minimum cell voltage can get.

JimmyMachE said:

Such extensive telemetry can be done in MME with Car Scanner app, Phidauex already posted several charts and data sets.

It would be interesting to log the average module voltage and minimum module voltage under continuous max load in Car Scanner, to see how low the minimum cell voltage can get.

Click to expand...

I'd be curious on the min cell voltage under two tests:

1) Hard acceleration from 20-100mph (as fast as possible)
2) Slow steady acceleration from 20-100mph (in a minute).

The ID.4 uses 288 pouch cells (82 kWh) while the extended range Mach-E uses 376 pouch cells in 88 kWh (288 in the standard 68 kWh pack) so in theory... larger battery pack= lower IR = better performance (better acceleration at least with the "same motor + electronics").

If one could try (1) and determine at what mph the Mach-E hit say 3.6v (arbitrary.. could be 3.5v but no lower) that becomes the point where the car can not handle more rapid acceleration (it still is accelerating) with the existing rpm load. It could explain why the GT/GTPE aren't any faster than the Premium on the drag strip... if the Mach-E is battery limited then there is nothing software can fix.

In theory the GT/GTPE have larger electric motors and thus can handle more power (unsure if they are the same rpm as the other trims) but if the battery can't deliver that power then they are under-utilized.