Sandy Munro talks about the teardown of the Model 3

[TT97]

Actually it was stated that if the Model 3 was lighter in weight.....The tires would have less traction.

Traction control would software limit the slip thereby making the car slower. <---- That's a statement my Tesla.

I'm actually loosing quickness "right now" because I don't have the 10" tires on the rear ( which are heavier ). I put the 10 inch tires on my car this summer in Joliet and my 0-60 times were .3 seconds faster because there was no slip at all.

So....that's why I kept/keep saying that a lighter car is not always necessarily quicker.

What matters most is "where the weight is" and what its function is.

The dragster spoiler weighs about 200 pounds however the dragster would be well over a second slower in a quarter mile race.

Yes, that's why Formula 1 cars that weigh 1,616 lbs (with driver) are so slow.

10" tires don't have better traction because they are heavier, it's because they have a bigger contact patch.

 

[Garlan Garner]

Yes, that's why Formula 1 cars that weigh 1,616 lbs (with driver) are so slow.

10" tires don't have better traction because they are heavier, it's because they have a bigger contact patch.

Yes indeed. They don't have better traction because they are heavier...indeed.

My car is heavier with them , however its also quicker.

My point is. There is no golden rule that lighter is faster.

 

[Garlan Garner]

Yes indeed. They don't have better traction because they are heavier...indeed.

My car is heavier with them , however its also quicker.

My point is. There is no golden rule that lighter is faster.

With that said...I also believe that the Model 3 would lose all kinds of traction in 0-60 thrills IF it wasn't as heavy as it is.

Concerning true race cars.....spoilers by themselves slow a car down due to the amount of air that they catch - not to mention their actual weight..... HOWERVER the spoilers function produces massive downforce on the rear of the car that mashes the tires into the pavement resulting in the cars having tremendously better traction resulting in the car achieving much faster speeds and handling than being without them.


What this guy continues to do is talk about the amount of air the spoiler catches. He continues to talk about the weight of the spoiler. He only talks about one side of many things. Then people go clamoring after his evaluations and for some reason reads them like a bible or something.

Of course I remember when the golden rule was: less weight....faster car.

That's not totally true anymore.

 

[Roentgen]

Actually it was stated that if the Model 3 was lighter in weight.....The tires would have less traction.

Traction control would software limit the slip thereby making the car slower. <---- That's a statement my Tesla.

I'm actually loosing quickness "right now" because I don't have the 10" tires on the rear ( which are heavier ). I put the 10 inch tires on my car this summer in Joliet and my 0-60 times were .3 seconds faster because there was no slip at all.

So....that's why I kept/keep saying that a lighter car is not always necessarily quicker.

What matters most is "where the weight is" and what its function is.

The dragster spoiler weighs about 200 pounds however the dragster would be well over a second slower in a quarter mile race.

Like I said, a trade off in frame weight (if necessary for traction) could be made up by increased battery size, which is even better, right? Battery is everything in an EV.

LOL! Yes, I used to believe in the tooth fairy. Until I didn't anymore. A lot of people, especially in Russia, think Vladimir Putin is God's gift to humanity. There is this thing called ignorance. It's pretty common.

Here's another example of why Munro is not that bright. He raves about the Model 3's handling, says it drives like it's on rails.

Then he's critical of structural welds that make the chassis less flexible and more stiff than the competition. Yes, it also adds cost and weight. Well, what did he expect? That Tesla could build the chassis like the other manufacturers do and still have the superior handling and driving dynamics?

It's completely idiotic. Why anyone would hold him up as an authority on something that's out of his area of expertise is a real mystery to anyone with a rational mind.

We don't know if less welds necessarily = less stiffness. Maybe there are 300 welds currently in the car, and only 200 are necessary to maintain stiffness/integrity. That's still 100 excess welds that make no difference to the ultimate safety/performance of the car. Now, these are just numbers I'm pulling out of my butt, but you get my point? We just don't know where Tesla is on this spectrum, or where Munro is honestly. We're all just engaging in mental masturbation. I'm just saying that there's room for both sides here, and without actual facts, there's no way to prove who is more or less right.

 

[StealthP3D]

I'm just saying that there's room for both sides here, and without actual facts, there's no way to prove who is more or less right.

This isn't a court of law, proof isn't necessary. What we need is common sense, something that Munro is lacking. He was biased from the get-go with the panel gap variations. But that is primarily a manufacturing problem, not an engineering/design problem.

I know for a fact that Tesla engineers used structural design engineering software to simulate not only chassis stiffness but also crash safety and load transfer. They had certain goals in mind. I also know that Munro didn't - he is simply noting that the Tesla structure is more over-built compared to the cars he's torn down in the past. He assumes what was "good enough" for them is good enough for the Model 3. But he didn't do the calculations and I'll note the other cars didn't have 1/2 ton of battery slung underneath.

He admits the Model 3 handles exceptionally well, as if it were on rails, but cannot explain why it handles better than other cars he's tested. Common sense says Munro is out of his league here compared to the brilliant minds that engineered the chassis that handles so well. All he can see is that it's different and the panel gaps are not consistent. I also wouldn't be surprised if he's not a little butt hurt that they didn't want to hire him.

I'm not saying the Model 3 can't be improved and refined over time but I hope Tesla doesn't ruin it and make it average by bringing in the bean counters to tell them they can save $1 here and a $1 there. Because I really do think driving dynamics and safety are things people are willing to pay a few bucks for on a mass market car. But to assume, as Munro did, that different is BAD is ridiculous in the extreme because he didn't even look at the computer simulations that were used to custom design the structure to begin with.

After taking delivery of our first Model 3 I saw that it was a cut above and didn't know how long the introductory version would be available without the bean counters getting their fingers in the pie. So I ordered a second one right away.

 

[ricohman]

With that said...I also believe that the Model 3 would lose all kinds of traction in 0-60 thrills IF it wasn't as heavy as it is.

Concerning true race cars.....spoilers by themselves slow a car down due to the amount of air that they catch - not to mention their actual weight..... HOWERVER the spoilers function produces massive downforce on the rear of the car that mashes the tires into the pavement resulting in the cars having tremendously better traction resulting in the car achieving much faster speeds and handling than being without them.


What this guy continues to do is talk about the amount of air the spoiler catches. He continues to talk about the weight of the spoiler. He only talks about one side of many things. Then people go clamoring after his evaluations and for some reason reads them like a bible or something.

Of course I remember when the golden rule was: less weight....faster car.

That's not totally true anymore.

Really? I bet an identical Model 3 stripped of its interior, A/C, door panels and the glass replaced with polycarbonate would be faster.
Actually, I know it will be faster. I've done it already with many other vehicles over decades.
You speak like you've never built a race car. How many cars have you built?

 

[scaesare]

Yes, Tesla resolved the bearing issues on the AC induction motor used in the S/X and front of the 3. My understanding is that going to ceramic bearings solved the issue of arcing due to induced currents in the rotor (but that is all > first hand).
The latest revs of drive units have not had the milling noise issue, and previous units would theoretically have failed and been replaced under warranty.

They also now have shaft grounding brushes, although its not clear to me when those were incorporated.

 

[JeffC]

Not sure if anyone else has mentioned it already, but Sandy keep complaining that the Model 3 unibody is poorly engineered because it's heavier than it needs to be. TBH he seems confused by Tesla's largely novel use of high strength steels in the body to create a sort of steel composite that has varying stiffness and strength properties in different places in order to more effectively dissipate crash energy, particularly from the sides of the car.

High strength steel has been used in relatively limited ways in cars before, particularly in a few places in front crash structures, but the side crash structures that Tesla uses may be new in the way they make a composite of various different high strength and mild steels in different locations. For example the A, B, and C pillars have prominent vertical pieces of high strength steel, and door tie beams made of HSS tying the pillars together through the door panels. The HSS pillars blend into lower strength, but more deformable steel pieces progressively (e.g., through spot welds). This probably creates a progressive crash structure that can dissipate much energy in a very short distance by distributing the force from the stiff and strong HSS beams to the softer more ductile and malleable mild steel. If so, this is a brilliant design.

(Mild steel has an advantage over HSS in being able to absorb energy by deforming and stretching more. Stiffer steels on their own will break before they bend. Mild steel will bend before it breaks. In engineering language mild steels ultimate tensile strength is significantly higher in relative terms than its yield strength. Combining HSS and mild steels may result in a composite that improves crash performance synergistically. The HSS is like a backbone that transfers crash energy to the mild steel (where it's absorbed by deforming) while keeping the general structure mostly intact.)

And Sandy doesn't seem to understand it, based on his repeated ignorant/confused/derogatory comments about it.

For example, he claims in the video above that existing CAD software marks many parts of Tesla's metal body to be unnecessary. Most likely the CAD software was not designed to use a composite of different steels in this way. It too may be ignorant.


The result for Model 3 is superb crash performance from pretty much any direction. In fact, it's world best in most testing. Some of that could be due to novel engineering of steel composites. And that novel use of steel in turn could be due to novel use of CAD technology.

Most of Tesla's advances are likely due to software, not just in obvious places like Autopilot, but also in car design software, battery testing software, chemical design software, etc. As a Silicon Valley company Tesla seems well aware of the importance of software in all aspects of the products.

 

[Uncle Paul]

50/50 weight distribution is good for handling characteristics. If removing structural weight from the rear structure made the Model 3 nose heavy, would that be a good thing?

 

[StealthP3D]

Really? I bet an identical Model 3 stripped of its interior, A/C, door panels and the glass replaced with polycarbonate would be faster.
Actually, I know it will be faster. I've done it already with many other vehicles over decades.

Both the RWD LR Model 3 and the P3D with the OEM 18" Michelin MXM4 Primacy tires are on the ragged edge of being traction limited on most common types of blacktop, especially if the battery is warm and 90% charged and the pavement/air temperature is cool. This means that to get signifiicantly quicker 0-60 times from removing weight, you might need stickier tires. Yes, making a car lighter generally does make it faster but, when traction limited, there are other factors at play and the experiences you've had with ICE vehicles over the decades might not transfer directly to a car with the torque and heavy battery of the Model 3.

If lightness was Tesla's number one goal, at the expense of safety, chassis rigidity and handling, then obviously they wouldn't have made such a solid structure (and they would have saved a few bucks in the process and increased their city eMPG rating). But it's abundently clear that light weight was not their number one priority. Munro acts like this was due to inexperience, I think it was due to having a different set of priorities. And if you look at how much just the medical portion of a serious accident costs, I think it was a brilliant move.

Besides, I like the "carved from a single piece of billet" driving feel it provides. Autos that drove like Flexi-Flyers always offended the driver inside me. A lot of Americans actually prefer Flexi-Flyers because it helps the car achieve a very complient and quiet ride. Munro's teardown of the Model 3 uncovered a lot of attention to noise attenuation in the chassis which is convincing evidence that Tesla was well aware they were building a very rigid chassis that required extra attention to managing the transmission of sounds through the chassis.

No doubt, the Model 3 could have been built much more cheaply. I'm glad they didn't.

 

[ricohman]

Both the RWD LR Model 3 and the P3D with the OEM 18" Michelin MXM4 Primacy tires are on the ragged edge of being traction limited on most common types of blacktop, especially if the battery is warm and 90% charged and the pavement/air temperature is cool. This means that to get signifiicantly quicker 0-60 times from removing weight, you might need stickier tires. Yes, making a car lighter generally does make it faster but, when traction limited, there are other factors at play and the experiences you've had with ICE vehicles over the decades might not transfer directly to a car with the torque and heavy battery of the Model 3.

If lightness was Tesla's number one goal, at the expense of safety, chassis rigidity and handling, then obviously they wouldn't have made such a solid structure (and they would have saved a few bucks in the process and increased their city eMPG rating). But it's abundently clear that light weight was not their number one priority. Munro acts like this was due to inexperience, I think it was due to having a different set of priorities. And if you look at how much just the medical portion of a serious accident costs, I think it was a brilliant move.

Besides, I like the "carved from a single piece of billet" driving feel it provides. Autos that drove like Flexi-Flyers always offended the driver inside me. A lot of Americans actually prefer Flexi-Flyers because it helps the car achieve a very complient and quiet ride. Munro's teardown of the Model 3 uncovered a lot of attention to noise attenuation in the chassis which is convincing evidence that Tesla was well aware they were building a very rigid chassis that required extra attention to managing the transmission of sounds through the chassis.

No doubt, the Model 3 could have been built much more cheaply. I'm glad they didn't.

I built my first race car back in the mid 1980's. You are wrong. Sorry.

 

[StealthP3D]

I built my first race car back in the mid 1980's. You are wrong. Sorry.

That's definitely not a convincing arguement and it's not clear what you are saying I'm wrong about (because you quoted my entire post).

So, no, you didn't change my mind about anything because you didn't say anything.

 

[apsen]

Munro's videos are not hard to find but they are long and an incredible waste of valuable time.

No videos that I have found mention the stuff you are talking about. And your refusal suggests that you do not want me to find them. I wonder why...

 

[apsen]

I wouldn't call him an idiot though. I get the impression he knows quite a bit. But like you said, about traditional vehicle design. And although he may be mired in the old auto manufacturer mind-set, he was open minded enough to be publicly amazed at some of the brilliant engineering feats of the 3, and how some of that (like the superbottle) could not be accomplished by Detroit.

He may not be aware of stuff that is only known to Tesla and he openly admits that and that is a good thing. But some, I guess, would have been of better opinion of him if he have hidden that

There's also a lot of stuff that doesn't get a chance to be expressed and some assume that those videos are the whole story.

 

[voip-ninja]

Not sure if anyone else has mentioned it already, but Sandy keep complaining that the Model 3 unibody is poorly engineered because it's heavier than it needs to be. TBH he seems confused by Tesla's largely novel use of high strength steels in the body to create a sort of steel composite that has varying stiffness and strength properties in different places in order to more effectively dissipate crash energy, particularly from the sides of the car.

High strength steel has been used in relatively limited ways in cars before, particularly in a few places in front crash structures, but the side crash structures that Tesla uses may be new in the way they make a composite of various different high strength and mild steels in different locations. For example the A, B, and C pillars have prominent vertical pieces of high strength steel, and door tie beams made of HSS tying the pillars together through the door panels. The HSS pillars blend into lower strength, but more deformable steel pieces progressively (e.g., through spot welds). This probably creates a progressive crash structure that can dissipate much energy in a very short distance by distributing the force from the stiff and strong HSS beams to the softer more ductile and malleable mild steel. If so, this is a brilliant design.

(Mild steel has an advantage over HSS in being able to absorb energy by deforming and stretching more. Stiffer steels on their own will break before they bend. Mild steel will bend before it breaks. In engineering language mild steels ultimate tensile strength is significantly higher in relative terms than its yield strength. Combining HSS and mild steels may result in a composite that improves crash performance synergistically. The HSS is like a backbone that transfers crash energy to the mild steel (where it's absorbed by deforming) while keeping the general structure mostly intact.)

And Sandy doesn't seem to understand it, based on his repeated ignorant/confused/derogatory comments about it.

For example, he claims in the video above that existing CAD software marks many parts of Tesla's metal body to be unnecessary. Most likely the CAD software was not designed to use a composite of different steels in this way. It too may be ignorant.


The result for Model 3 is superb crash performance from pretty much any direction. In fact, it's world best in most testing. Some of that could be due to novel engineering of steel composites. And that novel use of steel in turn could be due to novel use of CAD technology.

Most of Tesla's advances are likely due to software, not just in obvious places like Autopilot, but also in car design software, battery testing software, chemical design software, etc. As a Silicon Valley company Tesla seems well aware of the importance of software in all aspects of the products.

So why did Musk supposedly say that he fired the idiot who did the body design?

You bring up some valid points but it is hard for me to believe that zero engineers working for Munro have any insight into the use of these materials.

 

[JeffC]

So why did Musk supposedly say that he fired the idiot who did the body design?

You bring up some valid points but it is hard for me to believe that zero engineers working for Munro have any insight into the use of these materials.

Thanks!

Musk fires a lot of people. It's not clear who Munro referred to.

The Model 3's unit body design is excellent and performs objectively well both in tests and real world crashes.

Munro's criticisms of it seem unfounded both in terms of results and also in terms his understanding of design purposes of the different materials.

Sandy admits that many things in Model 3 are unprecedented, from the quality of the electronics, to the power of the magnets, to the weight of the motor.*** He agrees that the non-Performance Model 3 drives very well. He finds that the battery cell and pack quality is unprecedented and world leading. He understands that the over the air updates are superior to anything other manufacturers have and understands some of the reasons why Tesla is able to do it but other car makers are not. Yet he seems unable to comprehend that Tesla may also be doing something unprecedented in the use of mixed steel composites in the body. Kind of a bizarre blind spot on his part.


*** By the way, he grossly understates the performance advantage of the Model 3 motor when noting that it's a few kg lighter than i3 or Bolt, while ignoring that it's vastly more powerful. The Model 3 motor is not slightly better than i3 or Bolt motors, it's vastly better if power to weight ratio is used as a measure.

 

[TT97]

*** By the way, he grossly understates the performance advantage of the Model 3 motor when noting that it's a few kg lighter than i3 or Bolt, while ignoring that it's vastly more powerful. The Model 3 motor is not slightly better than i3 or Bolt motors, it's vastly better if power to weight ratio is used as a measure.

In the video I watched, he stated that the Tesla motor is "root of two" faster than the other motors yet lighter and cheaper to fabricate. I didn't 100% get the reference, but by no way was he understating the performance. He even stated he believes the reason the Jaguar is much more inefficient than Teslas is due to the motor design (without taking apart a Jaguar).

 

[JeffC]

In the video I watched, he stated that the Tesla motor is "root of two" faster than the other motors yet lighter and cheaper to fabricate. I didn't 100% get the reference, but by no way was he understating the performance. He even stated he believes the reason the Jaguar is much more inefficient than Teslas is due to the motor design (without taking apart a Jaguar).

He probably means the motor has a higher top speed, but that's not the same as much more torque than the other motors of similar weight.

The square root of 2 is about 1.41, so it's about 41% faster, presumably than if the permanent magnets were not used in a more conventional reluctance motor design.

 

[StealthP3D]

No videos that I have found mention the stuff you are talking about. And your refusal suggests that you do not want me to find them. I wonder why...

I already told you why, I simply don't want to spend the time to re-listen to them to index them to what your requesting.

Here's a proposal: Since you are such a fan of Munro's opinions, just keep watching them until you find what you're looking for. In one of them he is standing by the trunk of a Model 3 and explaining how Tesla could save money and weight by simply stamping the trunk out of sheet steel like most car makers do instead of constructing it from multiple stampings welded together.

 

[Garlan Garner]

Really? I bet an identical Model 3 stripped of its interior, A/C, door panels and the glass replaced with polycarbonate would be faster.
Actually, I know it will be faster. I've done it already with many other vehicles over decades.
You speak like you've never built a race car. How many cars have you built?

You still aren't listening.

If you make all of those modifications you mentioned....then the car would be more expensive.

What modifications can you make that won't change the price?

I haven't built any cars myself, however I do cost analysis EVERY DAY on production and manufacturing.

For goodness sake..you could probably replace a lot of things on the Model 3 with carbon fiber....but can you do it with no up-charge.

Keep in mind that Tesla's don't have one purpose and the least likely purpose is being a track car.

Tesla Model 3's are safe / fast / quick / safe / family sedan / tech savy / safe / attractive / self driving / affordable ( for some ) / etc.... What modification can you make to improve the Model 3 and NOT change any of the factors that I listed?