Handling on AWD 3

[Daniel in SD]

I'm not sure I understand what you mean by the wheel size being the same? I'm assuming you mean width?

~$25k is a lot of play room for simply "more capable" inverters and motors, and bigger brakes. We also only know what size tires were offered with Tesla website 20" Sport wheel combo, and not what is finalized for the Performance Model 3. Seems like stiffer springs and ARBs with revised dampers would be a no brainer to improve performance, particularly if the target is better than BMW M3 performance in more than a straight line. The 4S tires are significantly more capable than the 18" Michelin Primacies and a good margin better than the 19" Contis. Didn't the P (non-D) Model S's that first came out have stiff suspension setups? Its not like they have done it before. They just have a much more capable chassis now in the Model 3.

I mean width. Looking at the picture of the P it sure looks like the tires are the same width as the LR. 20" wheels are just for looks and to fit bigger brakes. If they wanted to make it competitive with the BMW M3 they would have to give it a wider track to fit wider tires. That would require changes to the suspension. It would also require wider fenders.
I think the Tesla customer is very different from the BMW M customer. People are perfectly happy with the P100D even though the suspension is exactly the same as the 100D. The P85+ had stiffer suspension but there's probably a reason they stopped making it.

 

[scrapps]

If it’s anything to go by my 3 with a 20 staggered setup and pilot sports handles amazingly. I daren’t push it to the edge on public roads...
I can’t confirmation anywhere, do we know if the P has a square setup (the same as the wheels purchased separately?)

 

[moridin2002]

I mean width. Looking at the picture of the P it sure looks like the tires are the same width as the LR. 20" wheels are just for looks and to fit bigger brakes. If they wanted to make it competitive with the BMW M3 they would have to give it a wider track to fit wider tires. That would require changes to the suspension. It would also require wider fenders.
I think the Tesla customer is very different from the BMW M customer. People are perfectly happy with the P100D even though the suspension is exactly the same as the 100D. The P85+ had stiffer suspension but there's probably a reason they stopped making it.

It’s my understanding that they’re targeting the BMW M3 with the Model 3 Performance based on this Tweet:

“Cost of all options, wheels, paint, etc is included (apart from Autopilot). Cost is $78k. About same as BMW M3, but 15% quicker & with better handling. Will beat anything in its class on the track.”
Elon Musk on Twitter

 

[ℬête Noire]

It’s my understanding that they’re targeting the BMW M3 with the Model 3 Performance based on this Tweet:

“Cost of all options, wheels, paint, etc is included (apart from Autopilot). Cost is $78k. About same as BMW M3, but 15% quicker & with better handling. Will beat anything in its class on the track.”
Elon Musk on Twitter

The issue being sorting out if they're talking circuit track, drag strip, or just delusional market-speak.

 

[moridin2002]

The issue being sorting out if they're talking circuit track, drag strip, or just delusional market-speak.

Well, I would assume that people generally don't buy a BMW M3 solely for drag racing, particularly when considering the history that spawned the first M3s and subsequent models. Seems silly to me for a company targeting the performance of that car to solely focus on drag racing. (and likely covered by the 15% quicker comment). The BMW M3 has a certain market segment (performance compact luxury sedans) it competes in which includes others like the:
Mercedes Benz C63 AMG
Audi RS5/RS4
Lexus IS-F
Alfa Romeo Giulia Quadrifoglio
Cadillac ATS-V
Infiniti Q50 Red Sport 400
Volvo S60 Polestar

Point being, if Elon's comments truly indicate the performance targets for the Model 3 Performance version, my guess is that there would need to be more changes to the AWD Model 3 than just statistically sorted motors and inverters for more power capability, bigger brakes, and stickier Michelin tires. Or, like you said, its just marketing crap to get people to opt for the $78k Model 3.

 

[ℬête Noire]

Point being....

The same as mine. Only you've explained it in a lot more detail. The pitch would be something like "it is so much better in specific ways X & Y, which makes up for where it comes up shorter on W & Z ". It might even be a vaguely credible argument from some reasonable POV.

However as has been mentioned a few times before, without some sort of differential lock that doesn't rely on using brake slight-of-hand, it doesn't seem physically possible to match the BWM M3 much less exceed it in the frame of full circuit times across a wide variety of tracks. Late/poor acceleration coming out of corners is a lot to overcome with brute straight away acceleration when your curb weight is coming in at similar numbers.

The good news is that with the first P coming off the line, within weeks we should get our first 3rd party reports of what it can do.

 

[D3xDt3Reaction]

Or, like you said, its just marketing crap to get people to opt for the $78k Model 3.

If it’s more than just marketing, why not flaunt the useful hardware differences? Tesla has already produced one, so they obviously know what’s in it. Also, people are already making their buying decisions, so it’s in Tesla’s interest to tout what they’ve got. This is why I don’t think there are more differences than what you stated, nor do I think there are major differentiators vs. the AWD 3. Whether it will beat a BMW M3 around a track remains to be seen.

 

[moridin2002]

The same as mine. Only you've explained it in a lot more detail. The pitch would be something like "it is so much better in specific ways X & Y, which makes up for where it comes up shorter on W & Z ". It might even be a vaguely credible argument from some reasonable POV.

However as has been mentioned a few times before, without some sort of differential lock that doesn't rely on using brake slight-of-hand, it doesn't seem physically possible to match the BWM M3 much less exceed it in the frame of full circuit times across a wide variety of tracks. Late/poor acceleration coming out of corners is a lot to overcome with brute straight away acceleration when your curb weight is coming in at similar numbers.

The good news is that with the first P coming off the line, within weeks we should get our first 3rd party reports of what it can do.

I disagree on the limited slip argument because the Performance Model 3 will be AWD and will likely have much tighter and quicker control of effective wheel torque at any given moment (resolution and speed of torque control on an electric motor is likely to be an order of magnitude better than a traditional ICE). Lotus and McLaren (with the P1) have done some pretty incredible things without a limited slip diff and using only brake based torque vectoring. Corner exit acceleration is only one part of the equation.

 

[D3xDt3Reaction]

Or, like you said, its just marketing crap to get people to opt for the $78k Model 3.

If it’s more than just marketing, why not flaunt the useful hardware differences? Tesla has already produced one, so they obviously know what’s in it. Also, people are already making their buying decisions, so it’s in Tesla’s interest to tout what they’ve got. This is why I don’t think there are more differences than what you stated, nor do I think there are major differentiators vs. the AWD 3. Whether it will beat a BMW M3 around a track remains to be seen.

 

[ℬête Noire]

Lotus and McLaren (with the P1) have done some pretty incredible things without a limited slip diff and using only brake based torque vectoring.

But we've seen such poor results with prior attempts to implement such a thing in vehicles of more modest means, AKA under $1mil. I wonder if the brake system in the P1 is capable of faster cycle time and/or more precision control, so they were able to have better control, thus realize better results?

That would be interesting if the M3 P has something of an upgrade across the whole brake system (not just the calipers) and Tesla has been able to engineer a more reasonable facsimile of what Lotus McLaren has done? That'd be pretty exciting beyond what it means the M3 P can do, it'd mean the capability is moving down the cost scale.

Coming soon to a $35K car near you?

 

[MountainPass]

It looks like the Model 3 currently manages inside tire spin by reducing power, not by applying brakes (even with traction control disabled). So that is a pretty big hindrance that could likely be fixed with software, if the rear brakes can manage the extra heat.

My friend's M4 is going to come to the track shortly to go against our base RWD LR Model 3. On a short track where handling and braking is more important then power, I estimate our Model 3 will be between 1-2 seconds slower than his M4 (and M4 is just a 2 door M3) on the same tire, but it could be more. That is after our suspension and brake upgrades, which made the car 2.5 seconds faster than stock.

I don't think the PM3 is going to be faster than a BMW M3 if we're comparing on the same tire, unless Tesla makes changes to the suspension and firmware. The BMW is very fast in a straight line, it will be ~450lbs lighter than the Performance Model 3, and it has more aggressively tuned suspension and dynamics control. The stability and traction control is worth ~1.5 seconds per lap (obviously this is track dependent) as it stands now, whereas with the BMW you can turn all of that stuff off.

Tesla if you're reading this, please give us two track modes, one with very generous stability control and traction control, and one with everything off. Please also implement inside tire slip management with the ABS rather than reducing power.

Attached is an image of a sweeper at Gingerman comparing one run with the stability control disabled, and one with it enabled. You can see that even though the throttle position is at 100%, the battery power is indicating the motor isn't making full power - not even close, 80kW less at one point!! This one corner lost 0.627 seconds, although some of that is the driver (me) picking up the throttle later.

 

[moridin2002]

It looks like the Model 3 currently manages inside tire spin by reducing power, not by applying brakes (even with traction control disabled). So that is a pretty big hindrance that could likely be fixed with software, if the rear brakes can manage the extra heat.

My friend's M4 is going to come to the track shortly to go against our base RWD LR Model 3. On a short track where handling and braking is more important then power, I estimate our Model 3 will be between 1-2 seconds slower than his M4 (and M4 is just a 2 door M3) on the same tire, but it could be more. That is after our suspension and brake upgrades, which made the car 2.5 seconds faster than stock.

I don't think the PM3 is going to be faster than a BMW M3 if we're comparing on the same tire, unless Tesla makes changes to the suspension and firmware. The BMW is very fast in a straight line, it will be ~450lbs lighter than the Performance Model 3, and it has more aggressively tuned suspension and dynamics control. The stability and traction control is worth ~1.5 seconds per lap (obviously this is track dependent) as it stands now, whereas with the BMW you can turn all of that stuff off.

Tesla if you're reading this, please give us two track modes, one with very generous stability control and traction control, and one with everything off. Please also implement inside tire slip management with the ABS rather than reducing power.

Attached is an image of a sweeper at Gingerman comparing one run with the stability control disabled, and one with it enabled. You can see that even though the throttle position is at 100%, the battery power is indicating the motor isn't making full power - not even close, 80kW less at one point!! This one corner lost 0.627 seconds, although some of that is the driver (me) picking up the throttle later.

View attachment 311525

A couple of questions for you, particularly since you're doing all sorts of testing with the Model 3 and willing to share with all of us (no good deed goes unpunished ).

What is your sense of the driving authority mechanism for the stability/traction? Is it just looking for wheel slip at maybe some steering angle or lat-g (does the car record lat-g or is that the Motec's measurement)? Or, does it seem to be a little more tire model driven? For example, will the car pull the similar amounts of power and/or allow similar levels of peak gs regardless of whether you have the Primacies or your new, stickier rubber? And, does it seem to be different from, or is it similar to other vehicles that are not electric?

 

[moridin2002]

If it’s more than just marketing, why not flaunt the useful hardware differences? Tesla has already produced one, so they obviously know what’s in it. Also, people are already making their buying decisions, so it’s in Tesla’s interest to tout what they’ve got. This is why I don’t think there are more differences than what you stated, nor do I think there are major differentiators vs. the AWD 3. Whether it will beat a BMW M3 around a track remains to be seen.

Doesn't Tesla use different axle assemblies and rear drive units on their P versions of the Model S and X. They don't really advertise those. Its just part of the improved performance package.

 

[Daniel in SD]

Doesn't Tesla use different axle assemblies and rear drive units on their P versions of the Model S and X. They don't really advertise those. Its just part of the improved performance package.

I believe the original P85D had the same rear drive unit as the 85. They downsized the rear drive unit for 85D. The Model 3P will have the same drive unit as the LR but they'll take the best performing ones for the P. I wouldn't expect enough increase in torque to justify larger axles but who knows. It sounds like the AWD will also share the same drive unit but I wouldn't be surprised if they downsize it later to cut costs.

 

[MountainPass]

A couple of questions for you, particularly since you're doing all sorts of testing with the Model 3 and willing to share with all of us (no good deed goes unpunished ).

What is your sense of the driving authority mechanism for the stability/traction? Is it just looking for wheel slip at maybe some steering angle or lat-g (does the car record lat-g or is that the Motec's measurement)? Or, does it seem to be a little more tire model driven? For example, will the car pull the similar amounts of power and/or allow similar levels of peak gs regardless of whether you have the Primacies or your new, stickier rubber? And, does it seem to be different from, or is it similar to other vehicles that are not electric?

Lol, happy to share what I know, unless it relates to a product we are developing!

Right now the obvious one is the stability control. That is your standard car stability control that reacts to steering angle not matching yaw/lateral G. I.e. if you're asking for more steering input at a certain speed and not getting more yaw, understeer mitigation kicks in. If there is a lot of lateral G and/or yaw with little steering angle, oversteer mitigation kicks in. The Model 3, like any car with VDC, has a yaw sensor, steering angle sensor, four wheel speed sensors and an accelerometer.

The traction control is a little bit different and I'm not fully confident I understand it yet. It seems like when we have the stability control off and the drive unit still reduces power when it shouldn't that it is reacting to inside tire spin, but there might still be something happening on top of that. I have to go through all of the data to see if I can find any instances where there is power reduction and no signs of inside tire slip.

To throw a wrench into this whole thing our Bridgestone RE71R's are a little bit taller in the rear than the front. This may cause traction control or even inside tire spin control to be more sensitive than it normally would, as our rear speed is displayed as almost 1% higher than the front. This works out to 1% less slip you're allowed obviously.

We'll be at the track again this weekend and if it stays dry (it seems every time we run this car at the track it rains!) I'll try more front tire pressure and less rear tire pressure to see if that makes a significant difference on traction control.

 

[Daniel in SD]

Lol, happy to share what I know, unless it relates to a product we are developing!

Right now the obvious one is the stability control. That is your standard car stability control that reacts to steering angle not matching yaw/lateral G. I.e. if you're asking for more steering input at a certain speed and not getting more yaw, understeer mitigation kicks in. If there is a lot of lateral G and/or yaw with little steering angle, oversteer mitigation kicks in. The Model 3, like any car with VDC, has a yaw sensor, steering angle sensor, four wheel speed sensors and an accelerometer.

The traction control is a little bit different and I'm not fully confident I understand it yet. It seems like when we have the stability control off and the drive unit still reduces power when it shouldn't that it is reacting to inside tire spin, but there might still be something happening on top of that. I have to go through all of the data to see if I can find any instances where there is power reduction and no signs of inside tire slip.

To throw a wrench into this whole thing our Bridgestone RE71R's are a little bit taller in the rear than the front. This may cause traction control or even inside tire spin control to be more sensitive than it normally would, as our rear speed is displayed as almost 1% higher than the front. This works out to 1% less slip you're allowed obviously.

We'll be at the track again this weekend and if it stays dry (it seems every time we run this car at the track it rains!) I'll try more front tire pressure and less rear tire pressure to see if that makes a significant difference on traction control.

Were you were able to disable stability control but not traction control?
I see that Quaife makes an LSD for the Model S, I wonder if they'll make one for the Model 3.

 

[xav-]

It’s just me but I would say the RWD model 3 LR will “out handle” a BMW 330 or 340 with similar tires.

I strongly suspect that the SR Model 3 will destroy the BMW 3 series handling wise, although many will be tempted to use those ugly Michelin tires for the range.

 

[MountainPass]

Were you were able to disable stability control but not traction control?
I see that Quaife makes an LSD for the Model S, I wonder if they'll make one for the Model 3.

As far as I can tell right now, when we disable stability control it says "traction control disabled" but that doesn't seem to be totally true... I was sliding around in the rain and there was certainly traction control stopping things from happening.

Unplugging a wheel speed sensor could totally remove traction, but you'd lose ABS.

 

[D3xDt3Reaction]

Doesn't Tesla use different axle assemblies and rear drive units on their P versions of the Model S and X. They don't really advertise those. Its just part of the improved performance package.

Good question, but would that be an inherent handling/performance differentiator or just a necessary ingredient in the package? Regardless, those who are spending six figures on a car probably use a different calculus for value - many who would spend another $24k on a P 3 want more differentiators than 1s off 0-60 plus some “goodies”. Seems incumbent on Tesla’s marketing to make those things known if they exist. I’m sure Tesla will still sell a lot of P models anyway though.

 

[moridin2002]

Looks like Tesla has updated their configurator: