MG4 Restricted speed - weird

[bowfer]

Another development…
Noticed when booting it onto the bypass tonight.
70% charge, floored throttle.
The power meter showed 100% then started tumbling going down over a couple of seconds, stopping at 52% (which resulted in around 70ish mph)

 

[AndyL61]

Another development…
Noticed when booting it onto the bypass tonight.
70% charge, floored throttle.
The power meter showed 100% then started tumbling going down over a couple of seconds, stopping at 52% (which resulted in around 70ish mph)

Have you tried feeding the power in a little more progressively rather than just flooring it ? Not suggesting you shouldn't floor it , just to see if it makes a difference and builds the power rather than reduces it .

 

[bowfer]

Have you tried feeding the power in a little more progressively rather than just flooring it ? Not suggesting you shouldn't floor it , just to see if it makes a difference and builds the power rather than reduces it .

Doesn’t seem to matter as it’s way past the point of power application, if you know what I mean.
The point at which I applied the power was about 100 yards previously, maybe more.
So it’s not happening ‘as soon’ as I floor it, it’s happening quite a bit after.

 

[FiferMG4]

Another development…
Noticed when booting it onto the bypass tonight.
70% charge, floored throttle.
The power meter showed 100% then started tumbling going down over a couple of seconds, stopping at 52% (which resulted in around 70ish mph)

Bowfer, do you happen to know what setting your speed limit assistance system is set to, intelligent, manual or off?

 

[bowfer]

Bowfer, do you happen to know what setting your speed limit assistance system is set to, intelligent, manual or off?

Off, never on.

 

[Ayoull]

The motor is rated for 100% power for 30seconds is my understanding, at which point it will throttle back to prevent damage to itself

 

[bowfer]

The motor is rated for 100% power for 30seconds is my understanding, at which point it will throttle back to prevent damage to itself

If you mean a continuous 30 seconds, it’s not that long.
If it’s a cumulative 30 seconds over a period of time, that’s more of a concern.
My journey home is a series of short full throttle bursts over around 10 minutes.
If it can’t handle that then it’s the first car that can’t and will be rejected immediately.
Do you have anything to give me more of an idea?

 

[john andersen]

There was a post about the fan kicking in on their car when accelerating, question is do you feel it ? so if you are pushing the motor and it is not getting the cooling needed. or it is a cell balance problem ?

 

[bowfer]

There was a post about the fan kicking in on their car when accelerating, question is do you feel it ? so if you are pushing the motor and it is not getting the cooling needed. or it is a cell balance problem ?

No idea what the fan feels like.
It seems unlikely to be an overheating problem when it’s 3.5 miles in close to freezing temps.

 

[john andersen]

Battery Cooling Pump, Vibration on acceleration. Anyone else?

OK, I’ve done 250 miles in my Trophy since last Friday. I notice a vibration through the car when accelerating hard. I don’t do that very often but the vibration is definitely there. I think that the vibration may be from a cooling fan that kicks in when the battery is being pressed hard but I...

www.mgevs.com

There are 2 coolant system in the car, and if the motor one is not pumping coolant about the motor will heat up, makes me wonder how much coolant you have for the motor ?

 

[Ayoull]

This is from the manual, I can't find the documents where I found the time frame for throttling from.

But it is common in all cars including ICE the difference is when you floor an ICE you increase RPMs which at the top of the RPM range isn't the peak power output of the engine it is usually around 20-30% below this level so you're not constantly stressing the engine, if you could keep it in the bhp sweet spot of the engine in an ICE you would eventually feel it throttling via the ECU.

Where as in an EV 100% power foot to floor is exactly that.

 

[bowfer]

This is from the manual, I can't find the documents where I found the time frame for throttling from.

But it is common in all cars including ICE the difference is when you floor an ICE you increase RPMs which at the top of the RPM range isn't the peak power output of the engine it is usually around 20-30% below this level so you're not constantly stressing the engine, if you could keep it in the bhp sweet spot of the engine in an ICE you would eventually feel it throttling via the ECU.

Where as in an EV 100% power foot to floor is exactly that.

I’m not sure what posting a screenshot of the tech spec of the motor is supposed to be illustrating?

 

[bowfer]

Battery Cooling Pump, Vibration on acceleration. Anyone else?

OK, I’ve done 250 miles in my Trophy since last Friday. I notice a vibration through the car when accelerating hard. I don’t do that very often but the vibration is definitely there. I think that the vibration may be from a cooling fan that kicks in when the battery is being pressed hard but I...

www.mgevs.com

There are 2 coolant system in the car, and if the motor one is not pumping coolant about the motor will heat up, makes me wonder how much coolant you have for the motor ?

Again, it’s a 3.5 mile commute in low temperatures.
My leafs managed being used hard for those three miles without any form of active cooling.

 

[Ayoull]

I’m not sure what posting a screenshot of the tech spec of the motor is supposed to be illustrating?

That there is a peak and constant power rating, no motor can output it's peak rating infinitum electric or mechanical.

I am still trawling through the many documents I have saved about the MG4 and it's components looking for the peak output time scale before throttling

 

[tsedge]

If you mean a continuous 30 seconds, it’s not that long.
If it’s a cumulative 30 seconds over a period of time, that’s more of a concern.
My journey home is a series of short full throttle bursts over around 10 minutes.
If it can’t handle that then it’s the first car that can’t and will be rejected immediately.
Do you have anything to give me more of an idea?

Nobody should need full throttle for any normal journey in anything except an ultra-slow EV (which the MG is not).

This suggests to me that your driving style is far outside the norm and may in part explain why it isn’t living up to your expectations.

The SR motor and battery are designed for low cost and are less able to sustain high levels of power than the LR.

It does sound like you are having some exceptional problems, but the idea that you routinely use full throttle over and over again in your normal journey - that is simply not how most people drive.

 

[bowfer]

Nobody should need full throttle for any normal journey in anything except an ultra-slow EV (which the MG is not).

This suggests to me that your driving style is far outside the norm and may in part explain why it isn’t living up to your expectations.

The SR motor and battery are designed for low cost and are less able to sustain high levels of power than the LR.

It does sound like you are having some exceptional problems, but the idea that you routinely use full throttle over and over again in your normal journey - that is simply not how most people drive.

Quite frankly, I don’t care.
Every other car I’ve owned has coped perfectly fine, stop using my driving style to excuse a very obvious problem.
If it honestly cannot cope with having me put my foot down a couple of times in a very short commute then that’s a poor excuse for a car.
What about the others in here suffering the same issue that maybe don’t drive like me?
Honestly, have a word with yourself insinuating it’s my driving style that’s to blame and I should somehow molly-coddle it because it’s the base model….
Good grief, haha!

 

[tsedge]

Quite frankly, I don’t care.
Every other car I’ve owned has coped perfectly fine, stop using my driving style to excuse a very obvious problem.
If it honestly cannot cope with having me put my foot down a couple of times in a very short commute then that’s a poor excuse for a car.
What about the others in here suffering the same issue that maybe don’t drive like me?
Honestly, have a word with yourself insinuating it’s my driving style that’s to blame and I should somehow molly-coddle it because it’s the base model….
Good grief, haha!

Please calm down.

Your driving style is relevant since the power restriction may be due to it. MG may have designed the SR to only allow short non-repetitive bursts of acceleration.

You may not care but it is relevant for others to know - which is why I pointed it out.

I did acknowledge that it seems like you have a problem on top of that.

Yes, others also seem to have a problem in some cases, I did not deny that.

 

[Ayoull]

Quite frankly, I don’t care.
Every other car I’ve owned has coped perfectly fine, stop using my driving style to excuse a very obvious problem.
If it honestly cannot cope with having me put my foot down a couple of times in a very short commute then that’s a poor excuse for a car.
What about the others in here suffering the same issue that maybe don’t drive like me?
Honestly, have a word with yourself insinuating it’s my driving style that’s to blame and I should somehow molly-coddle it because it’s the base model….
Good grief, haha!

The guy on Facebook who had issues 25mi in to his ownership has had a software update applied that has fixed it according to his Facebook post I saw today.

Even an ICE vehicle will not cope with full power output without the ECU throttling the engine, the difference is foot to the floor in an ICE quickly speeds past the maximum output point of the vehicles power band, as its usually between 40-70% of its RPM range depending on the engines intended purpose i.e. sports car, or truck.

Where as in an EV maximum output is at the top of the motors rpm range, so it is easier to sustain this position in comparison to an ICE

 

[bowfer]

Please calm down.

Your driving style is relevant since the power restriction may be due to it. MG may have designed the SR to only allow short non-repetitive bursts of acceleration.

You may not care but it is relevant for others to know - which is why I pointed it out.

I did acknowledge that it seems like you have a problem on top of that.

Yes, others also seem to have a problem in some cases, I did not deny that.

It’s not relevant and it’s not due to it.
The fact others are suffering the same thing under different driving scenarios proves it.

 

[Ayoull]

It’s not relevant and it’s not due to it.
The fact others are suffering the same thing under different driving scenarios proves it.

Unfortunately it is relevant as it may be a factor, unless you or I were present for any of the other people's power issues we can't say it's due to the same or different driving scenarios.