[bavarianride]

Originally Posted by spool twice

I'm going to predict:

0-60 3.2
1/4 mile 11.4@123-124mph

Probably being optimistic, but perhaps not? BMW historically has sandbagged their acceleration time and I'm thinking this car will align itself right between the RWD M3/M4 and x-drive M3/M4 in acceleration #'s.

Those predictions look quite respectable, and will cause some Tesla owners to return to BMW

[NISFAN]

Originally Posted by techwhiz1

Larger rims are needed to cover larger brakes.

Rule number one in cars is that brakes must stall the motor at any speed. The majority of braking force is at the front. Ask Toyota about that failure.

So you go with the smallest wheel that will fit over the brakes and a wide enough tire to guarantee you won't burn the tires up. A 370mm rotor is 14.5" in diameter before you add caliper. you need an 18 or 19 inch wheel clear

Square setups work fine on street cars that are tracked, but I haven't see a square setup on anything racing in F1, ALMS, European Touring Car, or any other series I follow.

Even with a staggered setup you can dial out understeer.

It's more complicated that just rotating mass.
You need to take into swept area for brakes, heat capacity, rotating mass, etc.... Just because you make the wheel larger does not mean lower performance is all I'm saying.

All things equal bigger rims equals lower performance. Show > Go.

But do you care? Especially on a 2.25 ton EV. I mean it's not like you'll be rocking up at Laguna Seca to get in a few PB's anytime soon.

[NISFAN]

Originally Posted by spool twice

my reasoning to ask the question is more to find out what is the true reason behind limiting it?

Heat?

Battery depletion reasons?

Motor RPM limitations?

I don't necessarily intend to get anywhere near the 140mph limit, nor do I care that it's limited there, it was to find the reasoning behind it.

It has a single speed drive system. Motor RPM at 140mph will be crazy high. I think maximum power on the BMW e40 is rated at 17,000 rpm with an 8.77:1 gear ratio. They don't have special bearings so it would be crazy to run them that high for extended periods.

But also high speeds really deplete an EV battery, and generate exponentially high heat, so it becomes an impractical exercise to run an EV at high speeds.

[hotrod182]

Originally Posted by spool twice

Yes, and his street surface may not have been the best either due to the rain in the area previously. I think with a 1 ft rollout and 19" wheels it may trim it down .3-.4 seconds once it hits official test results.

It's too bad he couldn't do the test again with a smaller SOC, but given the video you posted of the i4 accelerating 120+ kph, it seems to be rather strong still.

I'm going to predict:

0-60 3.2
1/4 mile 11.4@123-124mph

Probably being optimistic, but perhaps not? BMW historically has sandbagged their acceleration time and I'm thinking this car will align itself right between the RWD M3/M4 and x-drive M3/M4 in acceleration #'s.

Unfortunately it seems the Matt Watson does use the 1ft roll outs on his Car Wow tests. Look at at 3:30 point of this video where the guy talks about the .4 sec difference. Which means his 3.62 run would be closer to 3.9 secs. The BMW simply launches softly compared to the Tesla.

[ZCD1]

Originally Posted by NISFAN

It has a single speed drive system. Motor RPM at 140mph will be crazy high. I think maximum power on the BMW e40 is rated at 17,000 rpm with an 8.77:1 gear ratio. They don't have special bearings so it would be crazy to run them that high for extended periods.

But also high speeds really deplete an EV battery, and generate exponentially high heat, so it becomes an impractical exercise to run an EV at high speeds.

But the Tesla Model 3 Performance’s top speed is 163 mph, also without a multi-speed transmission, so does that mean that the I4’s final drive ratio is numerically higher?

[spool twice]

Originally Posted by ZCD1

But the Tesla Model 3 Performance’s top speed is 163 mph, also without a multi-speed transmission, so does that mean that the I4’s final drive ratio is numerically higher?

What are the Tesla motor specs?

[NISFAN]

Originally Posted by spool twice

What are the Tesla motor specs?

Model 3 is 9.03:1 drive ratio, so slightly more motor rpm per mph, but the motor can do 18,500 rpm, or at least it nearly does at 163mph.

I'd imagine the model 3 aerodynamics are significantly better than the i4, so would naturally have a higher top speed potential. Bit of a moot statistic on an EV though. :

[ZCD1]

Originally Posted by NISFAN

Model 3 is 9.03:1 drive ratio, so slightly more motor rpm per mph, but the motor can do 18,500 rpm, or at least it nearly does at 163mph...
Bit of a moot statistic on an EV though. :

So that points to the BMW’s motor’s lower maximum motor rpm as the biggest reason for its “limited” top speed.

It was another poster who asked for the reason for the i4’s relatively low maximum speed, so it’s not a “moot” statistic for this discussion (or in Germany).

[NISFAN]

Originally Posted by ZCD1

So that points to the BMW’s motor’s lower maximum motor rpm as the biggest reason for its “limited” top speed.

It was another poster who asked for the reason for the i4’s relatively low maximum speed, so it’s not a “moot” statistic for this discussion (or in Germany).

The motor designs are similar, so it is most likely a BMW imposed limit rather than a "technically incapable" one. Spinning a motor at 18,500rpm on steel bearings is pushing the limits. I guess BMW have less appetite for risk.

The other factor could just be car / drivetrain dynamics. The cD and frontal area are different on both cars, worse for BMW. At top speed that makes a huge difference, especially so on electric motors that shed torque with rpm much more than an ICE. It is possible that even unrestricted the BMW M50 is not capable of accelerating much beyond 140mph, so it was pegged at a round number (225km/h).

As for my point about relevance of top speed. Any EV would be using up massive amounts of power at those speeds. It isn't something you could sustain for long periods as your range would be dropping like a Mig 29 on afterburner. You are also likely to start having LIMP mode from overheated battery/ motor, so not the most effective way to travel in real world situations.

[bavarianride]

Originally Posted by NISFAN

The motor designs are similar, so it is most likely a BMW imposed limit rather than a "technically incapable" one. Spinning a motor at 18,500rpm on steel bearings is pushing the limits. I guess BMW have less appetite for risk.

The other factor could just be car / drivetrain dynamics. The cD and frontal area are different on both cars, worse for BMW. At top speed that makes a huge difference, especially so on electric motors that shed torque with rpm much more than an ICE. It is possible that even unrestricted the BMW M50 is not capable of accelerating much beyond 140mph, so it was pegged at a round number (225km/h).

As for my point about relevance of top speed. Any EV would be using up massive amounts of power at those speeds. It isn't something you could sustain for long periods as your range would be dropping like a Mig 29 on afterburner. You are also likely to start having LIMP mode from overheated battery/ motor, so not the most effective way to travel in real world situations.

Yes I tend to agree it is moot point to discuss top speed of 1-gear EV transmission.

Taycan does have 2-gear and should be capable of higher max speed compared to i4/Tesla, but Porsche plays it safe so that drivers won't go too fast.

[Sportstick]

Originally Posted by techwhiz1

Also,.let's not forget that as far as tech (ADAS) Tesla is not the leader. BMW, Mercedes, Audi, Cruise and Ford are all ahead of Tesla. Tesla's camera only system cannot be L3 since there is no redundancy in the camera system.

Google Nvidia GTC to see where Mercedes is. They are partnered with Nvidia and are using the Orin platform.

BMW has full L3 that will be available in the EU. Not available in the US due to regulatory issues.
Audi has L3 but stopped selling it because the regulations had not caught up.

So Tesla doesn't lead in ADAS. That is a fact.
BMW and Lucid both have in house motor tech that is just as or more advanced. BMW puts all the DSC at the motor. Lucid has done some interesting things also.

Battery tech? LG and others have caught up and are doing forward research. They face the same physics as everyone else.

Tesla has been very good at marketing.

We shall see how they do with real alternatives in the market
Lucid, BMW, VW, Audi, Porsche, GM, Ford are all in one or more segments that Tesla plays in.

I'm betting on the traditional guys that know how to make cars and have partnered with others for tech.

I'm also betting on some of the new guys; Rivian, Lucid, Fisker (not new).

All of these folks know how to make cars. Ultimately cars are what will sell. Unique and novel tech is great, but that's not what the market is going to want long term.
Build quality does matter and Tesla gets at best a grade of D+ for consistency.

An interesting and detailed article on the ADAS topic appeared today.

https://www.nytimes.com/2021/12/06/t...747ff4ab5667fa

[techwhiz1]

Originally Posted by Sportstick

An interesting and detailed article on the ADAS topic appeared today.

https://www.nytimes.com/2021/12/06/t...m-the-newsroom®i_id=45926354&segment_id=76223&te=1&user_id=f1393 9c5133a3ed538747ff4ab5667fa

And that article is no surprise to those that have worked on ADAS and ASIL technology.

That article mirrors exactly what I have said here about the Autopilot and Tesla. About camera only systems not being up to the task, etc., etc.

I feel vindicated.

[Sportstick]

Originally Posted by techwhiz1

And that article is no surprise to those that have worked on ADAS and ASIL technology.

That article mirrors exactly what I have said here about the Autopilot and Tesla. About camera only systems not being up to the task, etc., etc.

I feel vindicated.

You should, indeed. But, apparently, today, it goes even further, although the premise is difficult to imagine.

https://jalopnik.com/model-3-owner-s...ign=2021-12-07

[spool twice]

Jesus, that paint quality between panels...

[Haywood]

One of the commenters was spot on. When it starts to affect sales, they’ll start to care about QC. But until the i4 or similar starts to take marketshare (which could take awhile), Tesla doesn’t give two sh!ts. Lemmings will still line up.

[techwhiz1]

Originally Posted by spool twice

Jesus, that paint quality between panels...

The quality in general. :

[bavarianride]

Wow so after 4+ years of shipping Model 3, the paint and QC issues are still not fully resolved.

I still would buy a Model 3 if 250-300 miles costs $30k-ish MSRP before tax + fees and incentives, but these days a base Model 3 SR goes for $46k MSRP.

At those price ranges, many other BEVs, including high priced i4, become viable.

[spool twice]

does anyone have the final drive ratio of the M50?

[techwhiz1]

Originally Posted by bavarianride

Wow so after 4+ years of shipping Model 3, the paint and QC issues are still not fully resolved.

I still would buy a Model 3 if 250-300 miles costs $30k-ish MSRP before tax + fees and incentives, but these days a base Model 3 SR goes for $46k MSRP.

At those price ranges, many other BEVs, including high priced i4, become viable.

And the base model delivery is almost a year out. They don't want to sell base.

[Sportstick]

Originally Posted by bavarianride

Wow so after 4+ years of shipping Model 3, the paint and QC issues are still not fully resolved.

I still would buy a Model 3 if 250-300 miles costs $30k-ish MSRP before tax + fees and incentives, but these days a base Model 3 SR goes for $46k MSRP.

At those price ranges, many other BEVs, including high priced i4, become viable.

Why even at that price for that level of product quality?

I would trust a Fisker Ocean built by Magna much, much more, and with federal tax credit, just about right on the $30k price point for the base model.

https://www.motor1.com/news/548912/f...range-details/

[bavarianride]

Originally Posted by Sportstick

Why even at that price for that level of product quality?

I would trust a Fisker Ocean built by Magna much, much more, and with federal tax credit, just about right on the $30k price point for the base model.

https://www.motor1.com/news/548912/f...range-details/

Model 3 $30k before tax + fees and incentives will become $22.5k after $7.5k fed credit, and that price sounds OK for the build quality and range of a Model 3 base.

[bavarianride]

Originally Posted by techwhiz1

And the base model delivery is almost a year out. They don't want to sell base.

Tesla does not break down geographical sales, my guess is that Tesla has to ship most cars and parts to China while US sales likely is leveling off.

Or Tesla is hard hit by supply shortage and can only fill high priced orders.

Or Tesla has 250k-300k US customers taking up all of Fremont plant's capacity for next 12 months.