lightweight wheels model 3 performance 0-60 testing

[doms75d]

M3P has acceleration limit of 1g. It takes effect till around 78km/h, starting from this point m3p not able to get 1g due to powertrain design limitations.
If you are looking forward straight line acceleration- use narrowest possible front tyres with largest diameter and even larger diameter rear...i.e. 225/50/18F+265/45/18R(or whatever you can feet without scrubbing).
Always choose the lightest rim/tyres. It plays big role while you pass 1g start limit zone.
Alway get rid of any possible extra weight in car

 

[Lephturn]

It doesn't make much sense to apply limits based on acceleration rather than amps or power.

I agree there a computer limit but I'd be surprised if it accounts for weight in the car.

Please post some data. Do you also get the same acceleration with 1-3 passangers? Do the lightweight wheels change anything there?

I also have a lightweight wheels setup. No dragy yet so I can't test but interested

It makes sense to me that they limit it based on Gs. That way you get consistent acceleration at different states of charge. Some of these cars will have different battery packs with different chemistries, energy densities, and hence weight. By limiting acceleration to 1G they can get similar performance even with different battery packs in the car with different characteristics. If you think about it they already need the sensors to do this in order to manage regenerative braking in traction limited situations. They already have the sensors and the controls built to manage regenerative braking forces so it makes sense to me to use that same instrumentation and some of that functionality to limit both acceleration and deceleration.

 

[jackmott]

Saying it makes sense to limit acceleration based on G because it gets you consistent acceleration is pretty close to a tautology =)
I don't want it to be consistent!

I thought maybe it made sense to protect drivetrain parts but that doesn't make sense either.

 

[Lephturn]

Saying it makes sense to limit acceleration based on G because it gets you consistent acceleration is pretty close to a tautology =)
I don't want it to be consistent!

I thought maybe it made sense to protect drivetrain parts but that doesn't make sense either.

You left out "at different states of charge". That is the reason to use G for a limit. That likely makes it much easier to ensure that cars in the real world meet or exceed the efficiency and acceleration statistics that Tesla publishes. The mainstream media is super negative on Tesla and will blow any little thing out of proportion. Look at the class action lawsuits they are faced with around range and performance and it makes great sense to use G force as a limitation to ensure consistent and repeatable performance and range.

 

[dfwatt]

Thanks,

Interesting as why you barely saw an increase in acceleration? Maybe being software limited, as a reduction in unsprung mass should result in increased speeds.

Curious what your evidence is that acceleration is open quotes software limited close quotes? When we went from 28.5 lbs OEM stock wheels to 23-pound Wheels with no change in tires we consistently saw on draggy ~ almost a tenth of a second reduction from 3.30 on averaged to 3.22. This is not software this is Newtonian mechanics.

 

[dfwatt]

It makes sense to me that they limit it based on Gs. That way you get consistent acceleration at different states of charge. Some of these cars will have different battery packs with different chemistries, energy densities, and hence weight. By limiting acceleration to 1G they can get similar performance even with different battery packs in the car with different characteristics. If you think about it they already need the sensors to do this in order to manage regenerative braking in traction limited situations. They already have the sensors and the controls built to manage regenerative braking forces so it makes sense to me to use that same instrumentation and some of that functionality to limit both acceleration and deceleration.

These are upside-down concepts, and you're solving a problem that doesn't exist. Additionally, and clearly, the system gives different rates of acceleration at different states of charge particularly over a certain RPM where power falls off at low states of charge – all these are known facts. Tesla designed the system to run the inverters at a certain max level. The battery and motors are capable of a certain level of horsepower and torque. They don't need to slap on some additional limit to that arbitrarily so that the acceleration is always limited to a particular value. What in the world would prompt such a design? Electric motors are exceptionally smooth and deliver a consistent torque and way smoother horsepower curves than any internal combustion engine it's not even close in that regard so the notion that there's some software limit on all this other than of course the traction control system is pure fiction

 

[juanmedina]

I switched my stock wheels with 17lb Wedsport TC105x and with the same tires my 1/8th times didn't change at all. I took the car to the dragstrip multiple times.

 

[Lephturn]

These are upside-down concepts, and you're solving a problem that doesn't exist. Additionally, and clearly, the system gives different rates of acceleration at different states of charge particularly over a certain RPM where power falls off at low states of charge – all these are known facts. Tesla designed the system to run the inverters at a certain max level. The battery and motors are capable of a certain level of horsepower and torque. They don't need to slap on some additional limit to that arbitrarily so that the acceleration is always limited to a particular value. What in the world would prompt such a design? Electric motors are exceptionally smooth and deliver a consistent torque and way smoother horsepower curves than any internal combustion engine it's not even close in that regard so the notion that there's some software limit on all this other than of course the traction control system is pure fiction

I'm not solving anything, just speculating on why what we are observing may be true. Guys that dramatically reduce weight, and unsprung and rotating weight at that, do not see the increase in performance that they expect. Something is limiting that and I am speculating that it may be a G force limit and the reasons they may have done so. It seems that there is some sort of limit at play.

 

[dfwatt]

I'm not solving anything, just speculating on why what we are observing may be true. Guys that dramatically reduce weight, and unsprung and rotating weight at that, do not see the increase in performance that they expect. Something is limiting that and I am speculating that it may be a G force limit and the reasons they may have done so. It seems that there is some sort of limit at play.

Not all sources of information are equally reliable. You are crediting incredible sources. I just wouldn't do that. Please show me reliable data that you have collected that confirms that lightening the car by 200 lb does not reduce your 0 to 60 time by 2/10ths. Conversely, put a 200 lb person in the passenger seat and time your 0 to 60 and you will see it's about two-tenths of a second slower. I've done that experiment too. Have you? If you haven't done any of these empirical tests and you are just repeating nonsense, you are actually a conduit for disinformation.

Every time I've dropped significant rotating mass I've seen an improvement in the car's acceleration. The general metric is that a pound of wheel/tire weight equals about 4 lb of vehicle weight lost. For every documented hundred pounds that you strip out of the cars from interior lightening or replacing body panels with carbon fiber and other radical approaches, you can expect about a tenth 0 to 60 Improvement. That means however that only 25 lb of wheel/Tire weight gets you 1/10 quicker 0 to 60. That's been confirmed in my experience with draggy on two separate vehicles. We have two Performance Model 3s, so I've done this testing in relationship to two sets of 0 to 60 times. If you want to get more than 1/10 you've got to drop an awful lot of weight. It's simple Newtonian mechanics.

The notion that there is some kind of "G-Force limiter" on the acceleration of the car is simply an invention of the blogosphere. This invention ping-pongs around like all kinds of other silly rumors about the car, and about other things as well. It's just another form of disinformation out there and if you want to continue to spread it around by all means go for it. Covid vaccination could involve implanted microchips too.

 

[gearchruncher]

They don't need to slap on some additional limit to that arbitrarily so that the acceleration is always limited to a particular value. What in the world would prompt such a design? Electric motors are exceptionally smooth and deliver a consistent torque and way smoother horsepower curves than any internal combustion engine it's not even close in that regard so the notion that there's some software limit on all this other than of course the traction control system is pure fiction

If you hook the motor directly to the battery, the motor will melt while producing way more than rated power. (ignoring the AC/DC issues...)
The whole purpose of the motor controller is to limit current. It has all sorts of limits. Thermal, reliability, drivetrain shock, transmission torque capability, battery wear, etc.
And then there's marketing. Maybe you want to sell two variants without changing the hardware. Maybe you don't want the M3P to be faster than a Model S...

Oh wait, Tesla already does that. The LR, LR with acceleration boost, and M3P all have the same motors from the factory, just software limited. There's nothing to say they couldn't do acceleration boost on the M3P too. There's some data that the MYP outputs more power than the 3P, possibly to make up for the extra mass.

So, given we already know Tesla manages power output well below the physical capabilities of the drivetrain system, why are you so sure that they don't also manage to a specific acceleration? We have more data that Tesla limits power on cars in software than we do that they don't.

You say you have data that lowering weight improves acceleration. That's great, and pretty logical. But calling it completely illogical that Tesla would have a SW limiter is completely debunked by Tesla's own completely proven behaviors (and basically every car manufacturer ever).

 

[dfwatt]

If you hook the motor directly to the battery, the motor will melt while producing way more than rated power. (ignoring the AC/DC issues...)
The whole purpose of the motor controller is to limit current. It has all sorts of limits. Thermal, reliability, drivetrain shock, transmission torque capability, battery wear, etc.
And then there's marketing. Maybe you want to sell two variants without changing the hardware. Maybe you don't want the M3P to be faster than a Model S...

Oh wait, Tesla already does that. The LR, LR with acceleration boost, and M3P all have the same motors from the factory, just software limited. There's nothing to say they couldn't do acceleration boost on the M3P too. There's some data that the MYP outputs more power than the 3P, possibly to make up for the extra mass.

So, given we already know Tesla manages power output well below the physical capabilities of the drivetrain system, why are you so sure that they don't also manage to a specific acceleration? We have more data that Tesla limits power on cars in software than we do that they don't.

Further proof that a little knowledge is a dangerous thing. You've obviously advanced beyond mere Newtonian mechanics. What mechanics are you arguing for that underpin acceleration other than those basic equations? Love to hear it.

As for the Model Y possibly making slightly more power, that actually is credible, has been suggested by mountain passes own Dyno testing, and that's simply bumping up the inverter limit. Nobody knows whether or not the inverters are exactly the same or whether Tesla has slightly tweaked the inverters on the model y.

The rest of what you're saying is speculation, and pure filling in the blanks. I've done numerous tests with the car loaded and unloaded and I've never seen anything that violates Force equals mass times acceleration and the acceleration goes down because the mass goes up. Like I said please talk to Sir Isaac Newton about your new physics. As for your implied notion that somehow there's an accelerometer on the car that changes the inverter power level to make sure that the acceleration is the same across all these scenarios of lesser and greater weight, again please produce a single shred of data to support such an outrageous idea.

As for the notion that what you are arguing for is somehow consistent with the different power levels across the different trim levels, that's just again not true at all. The inverters are pegged at a Max Level depending on what version you've paid for and the max level in the performance version probably is set where Tesla figures is a max that the inverters, battery and motor can handle over the long-term. It's very unlikely that they would mess with that. The folks who've done the ghost module where you hack around Tesla's software inverter limit have been unable to find any extra power in the system. Are you saying you know something that they don't? If so this is just more pure fiction.

 

[dfwatt]

If you hook the motor directly to the battery, the motor will melt while producing way more than rated power. (ignoring the AC/DC issues...)
The whole purpose of the motor controller is to limit current. It has all sorts of limits. Thermal, reliability, drivetrain shock, transmission torque capability, battery wear, etc.
And then there's marketing. Maybe you want to sell two variants without changing the hardware. Maybe you don't want the M3P to be faster than a Model S...

Oh wait, Tesla already does that. The LR, LR with acceleration boost, and M3P all have the same motors from the factory, just software limited. There's nothing to say they couldn't do acceleration boost on the M3P too. There's some data that the MYP outputs more power than the 3P, possibly to make up for the extra mass.

So, given we already know Tesla manages power output well below the physical capabilities of the drivetrain system, why are you so sure that they don't also manage to a specific acceleration? We have more data that Tesla limits power on cars in software than we do that they don't.

You say you have data that lowering weight improves acceleration. That's great, and pretty logical. But calling it completely illogical that Tesla would have a SW limiter is completely debunked by Tesla's own completely proven behaviors (and basically every car manufacturer ever).

Actually if you connect the motor directly to the battery it will not produce any power at all certainly not "way more than its rated" kilowatts. It's an AC motor and you're connecting it to a DC power source. Please get educated before you expose your foolishness to public view on The Forum like this. Please!

 

[gearchruncher]

As for your implied notion that somehow there's an accelerometer on the car that changes the inverter power level to make sure that the acceleration is the same across all these scenarios of lesser and greater weight, again please produce a single shred of data to support such an outrageous idea.

You don't need an accelerometer (but of course there are ones). The motor controller already must know the speed of the motor in order to control an AC motor.

Acceleration is speed change over time. The controller can easily limit this. Why do you think the traction control in EV's is so great? They can easily manage the actual acceleration of the wheel, not only react to an external input, so the instant a wheel starts to accelerate in an illogical way, it immediately reduces torque.

Like you say, Tesla already has a power limit in the controller. An acceleration limit is just as easy, and for all we know, that's the way they actually limit power on an LR, not via direct Amps limits.

I am not saying Tesla is doing any of this. Data of weight reduction improving acceleration will disprove this. But it would be trivial for Tesla to do so, so we should be looking for data indicating they don't, not saying that is impossible.

As for the Model Y possibly making slightly more power, that actually is credible, has been suggested by mountain passes own Dyno testing, and that's simply bumping up the inverter limit. Nobody knows whether or not the inverters are exactly the same or whether Tesla has slightly tweaked the inverters on the model y.

Nobody knows? Tesla's own parts catalog shows the drive unit as an identical part number.

Tesla Model 3 Rear Drive Unit - openinverter.org wiki

openinverter.org

The folks who've done the ghost module where you hack around their software inverter limit have been unable to find any extra power in the system.

So? Tesla themselves already do this in the Model Y, proving the drive unit design has overhead in it.
Power in an EV is always a function of warranty, battery thermals, motor thermals, etc. The Model 3 motor can do way more power for a few seconds if Tesla wanted to, especially at low speeds.

 

[dfwatt]

You don't need an accelerometer (but of course there are ones). The motor controller already must know the speed of the motor in order to control an AC motor.

Acceleration is speed change over time. The controller can easily limit this. Why do you think the traction control in EV's is so great? They can easily manage the actual acceleration of the wheel, not only react to an external input, so the instant a wheel starts to accelerate in an illogical way, it immediately reduces torque.

Like you say, Tesla already has a power limit in the controller. An acceleration limit is just as easy, and for all we know, that's the way they actually limit power on an LR, not via direct Amps limits.

I am not saying Tesla is doing any of this. Data of weight reduction improving acceleration will disprove this. But it would be trivial for Tesla to do so, so we should be looking for data indicating they don't, not saying that is impossible.


Nobody knows? Tesla's own parts catalog shows the drive unit as an identical part number.

Tesla Model 3 Rear Drive Unit - openinverter.org wiki

openinverter.org

So? Tesla themselves already do this in the Model Y, proving the drive unit design has overhead in it.
Power in an EV is always a function of warranty, battery thermals, motor thermals, etc. The Model 3 motor can do way more power for a few seconds if Tesla wanted to, especially at low speeds.

Please do keep talking but only to yourself because I have you on ignore. I'm sure there's somebody else who wants to listen to this kind of stuff but count me out. I think you're just spinning theories and spinning your wheels. Fortunately the car doesn't spin its Wheels nearly as much.

 

[gearchruncher]

Actually if you connect the motor directly to the battery it will not produce any power at all certainly not "way more than its rated" kilowatts. It's an AC motor and you're connecting it to a DC power source. Please get educated before you expose your foolishness to public view on The Forum like this. Please!

Yeah, which is exactly why I said "(ignoring the AC/DC issues...)"
I actually work with electric powertrains for a living- I am well aware of what a controller does. Simplification is useful at times to make a point that the motor is much more capable than the controller generally allows, and the controller is almost always programmed to limit against the raw capability of the motor+battery.

In fact, you are the one showing your lack of knowledge thinking an AC motor controller would need an accelerometer in order to limit acceleration, given every AC controller already knows motor speed. An accelerometer isn't even particularly useful here if you want consistent 0-60 on non-flat surfaces. What is interesting here is that tire diameter changes may impact acceleration if only motor speed is used.

 

[Sam1]

Not all sources of information are equally reliable. You are crediting incredible sources. I just wouldn't do that. Please show me reliable data that you have collected that confirms that lightening the car by 200 lb does not reduce your 0 to 60 time by 2/10ths. Conversely, put a 200 lb person in the passenger seat and time your 0 to 60 and you will see it's about two-tenths of a second slower. I've done that experiment too. Have you? If you haven't done any of these empirical tests and you are just repeating nonsense, you are actually a conduit for disinformation.

Every time I've dropped significant rotating mass I've seen an improvement in the car's acceleration. The general metric is that a pound of wheel/tire weight equals about 4 lb of vehicle weight lost. For every documented hundred pounds that you strip out of the cars from interior lightening or replacing body panels with carbon fiber and other radical approaches, you can expect about a tenth 0 to 60 Improvement. That means however that only 25 lb of wheel/Tire weight gets you 1/10 quicker 0 to 60. That's been confirmed in my experience with draggy on two separate vehicles. We have two Performance Model 3s, so I've done this testing in relationship to two sets of 0 to 60 times. If you want to get more than 1/10 you've got to drop an awful lot of weight. It's simple Newtonian mechanics.

The notion that there is some kind of "G-Force limiter" on the acceleration of the car is simply an invention of the blogosphere. This invention ping-pongs around like all kinds of other silly rumors about the car, and about other things as well. It's just another form of disinformation out there and if you want to continue to spread it around by all means go for it. Covid vaccination could involve implanted microchips too.

So that means when I dropped 48 pounds of unsprung, rotational mass, removed the passenger and rear seats for another +/-100 pounds (about 300 pounds of dead weight removal using your estimate), and turned an identical 0-60, 1/8, 1/4, and 1/2 mile dragy times, that dragy's gps data was wrong and it should've been faster?

 

[gearchruncher]

that dragy's gps data was wrong and it should've been faster?

Yes. Newton's 4th law clearly states: Motor controllers can only control power output, not acceleration or velocity, and shall only have a simple max power output limit. Anything else is pure fiction.

 

[raptor5244]

It sure does feel like a Tesla developer has a line of code that reads something like:

If M3P
then set max acceleration time to 3.1 sec
If M3 LR
and Acceleration Boost = True
then set max acceleration time to 3.5 sec
else set max acceleration time to 4.0 sec.

 

[raptor5244]

Model Y testing showing differences in 0-60mph with different wheels.

Tesla Model Y wheels and its impact on 0-60 acceleration

With the Tesla Model Y just beginning first deliveries a few weeks ago, owners are getting their first tastes of how the new all-electric crossover performs. Brian Jenkins from YouTube channel i1Tesla took his experiments a few steps further and recorded the Model Y Performance 0-60 MPH...

www.teslarati.com

 

[gearchruncher]

Model Y testing showing differences in 0-60mph with different wheels.

Those wheels also had dramatically different diameters. He also uses slip start. Too many different factors for a controlled test.

The actual controlled test is like someone said. Put 400lbs of your favorite people in the car, do a 0-60, then kick 'em out. Did the acceleration change?

No way lightweight wheels are worth as much as 400lbs in the car. We're obeying physics here, right?