lightweight wheels model 3 performance 0-60 testing

[Sam1]

You kinda did The very definition of controlling an AC motor is a variable frequency drive. All Teslas have to be able to control current and frequency, and not in quantized steps. You need to be able to go from 1372Hz to 1373 Hz as the car speeds up.

The Plaid has a different motor- the carbon wrap is important but not for RPM reasons as everyone thinks. But as posted above, plaid runs LOWER RPM than other cars, not higher. You can't just keep your torque up at higher RPM's with software- you need new motor designs, and you need to focus on torque not RPM. At a minimum, this also means a new controller that can handle higher currents as well.

If Tesla really could increase performance with a software update, and they know how to do it due to learning it in the Plaid, you don't think they would have a $5000 OTA option?

They definitely wouldn't do a massive performance upgrade OTA. Every time the envelope is pushed, it opens them up to more warranty repairs. And honestly, the majority of people are probably amazed at the 0-100 capabilities because they rarely if ever go beyond that. Just a few of us that do it regularly...And even fewer of those that just don't want to switch to a large model S to do it in. I'd gladly fork out an extra 10k for a M3P to get one in the low 10's in the 1/4 by having the top end align more so with the acceleration of the bottom end.

 

[gearchruncher]

I'd gladly fork out an extra 10k for a M3P to get one in the low 10's in the 1/4 by having the top end align more so with the acceleration of the bottom end.

100%. I'd do the same. But it's going to need to be like a Plaid as well- completely different drive units, not just a software update, and these new drive units would likely do lower RPM than current ones like Plaid does.

 

[raptor5244]

I expect if the 2 speeds made any sense Tesla would've done that for the Plaid.

Remember the original roadster had a 2-speed, something Tesla has not repeated since. Porsche has, and it still pales in performance compared to the Plaid.

I wonder if they will be able to bring the cost of the Plaid motor tech down to the $60-70k price point vs. the cost of implementing a 2-speed transmission.

Automatic transmissions have improved dramatically in the past 10 years and a simple 2-speed should be fairly simple for most manufacturers. I agree that the simplicity of a single speed trans is ideal for typical commuting but for performance applications a 2-speed could get you significant performance improvements at a much lower cost. Folks that like to track their cars would appreciate it on the longer straights.

For example, my ZL1 A10 shifts like this, it literally feels like one gear during a pull as it snaps off the shifts so fast. I would think a simple 2-speed transmission would make sense if it could net big gains in the 70-130mph range.

 

[gearchruncher]

I wonder if they will be able to bring the cost of the Plaid motor tech down to the $60-70k price point vs. the cost of implementing a 2-speed transmission.

Automatic transmissions have improved dramatically in the past 10 years and a simple 2-speed should be fairly simple for most manufacturers. I agree that the simplicity of a single speed trans is ideal for typical commuting but for performance applications a 2-speed could get you significant performance improvements at a much lower cost. Folks that like to track their cars would appreciate it on the longer straights.

I guarantee the motor in the Plaid costs less than a transmission. The Plaid is value priced right now, not cost priced. I mean, it costs the same as an older Model S Ludacris, which was just a Model S with a few uprated components. The bigger issue probably is the wear on the battery, which transmissions don't help with at all (power is power).

And remember, you'd need THREE transmissions as the way the Plaid gets all that power is basically two Model 3 motors in the rear, completely decoupled, and then the front one. If you don't do all 3, you now do have a drop off at higher speeds.

Tesla would kind of laugh at you that a 2 speed transmission should be simple. EV motors deliver way more torque than ICE engines and the last time they tried it, it kept blowing up. I don't think there's any proof that the last 10 years have solved this issue easily given only one EV has even attempted a transmission, and then only one of them.

That's the actual amazing thing about the Plaid, which is that Tesla has figured out how to keep the power output pretty flat across a useable RPM band. This tech will quickly become the normal over the next few years as Tesla gets more competition and I bet in 5 years, 2.0 second 0-60's will be pretty normal. It's just not that expensive to do in an EV.

 

[Sam1]

I wonder if they will be able to bring the cost of the Plaid motor tech down to the $60-70k price point vs. the cost of implementing a 2-speed transmission.

Automatic transmissions have improved dramatically in the past 10 years and a simple 2-speed should be fairly simple for most manufacturers. I agree that the simplicity of a single speed trans is ideal for typical commuting but for performance applications a 2-speed could get you significant performance improvements at a much lower cost. Folks that like to track their cars would appreciate it on the longer straights.

For example, my ZL1 A10 shifts like this, it literally feels like one gear during a pull as it snaps off the shifts so fast. I would think a simple 2-speed transmission would make sense if it could net big gains in the 70-130mph range.

the problem with the trans is that the motors put out crazy amounts of torque at speeds a gas car can't imagine. A shift on an EV means they'll also have to mellow out that punch and bring it back in, also negating the benefit of having max power instantly. It's really a toss up - great for efficiency and cruising, not so great on acceleration metrics. Obviously there are tons of things to consider, like how fast it can shift, how slow they have to ramp back up the power - so say it's a 90ms shift (same as my BMW), then the car has to pull 25% power for the shift, and ramp back up that 25% retard through another 50ms. That's almost 1/10 of a second under no power and 1/20 of a second under partial power. Just as an example of things to consider.

 

[raptor5244]

the problem with the trans is that the motors put out crazy amounts of torque at speeds a gas car can't imagine. A shift on an EV means they'll also have to mellow out that punch and bring it back in, also negating the benefit of having max power instantly. It's really a toss up - great for efficiency and cruising, not so great on acceleration metrics. Obviously there are tons of things to consider, like how fast it can shift, how slow they have to ramp back up the power - so say it's a 90ms shift (same as my BMW), then the car has to pull 25% power for the shift, and ramp back up that 25% retard through another 50ms. That's almost 1/10 of a second under no power and 1/20 of a second under partial power. Just as an example of things to consider.

Makes sense, I just thought current transmissions can handle those torque loads. We see Dodge, GM and Chevy using ZF, Tremec, etc. supporting their high torque output models but as you mention they are probably dialing in a lot of torque management to save the drivetrain.

 

[Sam1]

Makes sense, I just thought current transmissions can handle those torque loads. We see Dodge, GM and Chevy using ZF, Tremec, etc. supporting their high torque output models but as you mention they are probably dialing in a lot of torque management to save the drivetrain.

For sure there are plenty of transmissions that can handle 1000tq, but unless it's something like a 6,000hp funny car, the ramp up to peak tq is like / where an EV the ramp starts at the top like | ... Then you get into a 'how much will it cost to handle X amount and be reliable' debate.

Everything is possible, but durability, cost etc. are major factors.

 

[Sam1]

in other news, looks like Tesla just cranked up the plaid to 175mph in track mode.

175 MPH Top Speed Update with Track Mode in the Tesla Plaid | 175 MPH Top Speed Update with Track Mode in the Tesla Plaid | By DragTimes.com hosted by Brooks WeisblatFacebook

175 MPH Top Speed Update with Track Mode in the Tesla Plaid

www.facebook.com

 

[Gauss Guzzler]

Actually these electric motors have pretty modest torque. 300 ft-lbs for example on the rear Model 3 Performance motor, so about the same as mom's Camry. But unlike that clunky Camry which jackhammers the geartrain with every exploding pterodactyl, an electric motor delivers smooth torque so the gearbox loads are actually much milder.

And when shifting gears a fossil car has all sorts of pistons flailing around and heavy counterweights and junk resulting in much higher rotational inertia to slam much harder into the next gear, nevermind the fact that electric motors can be commanded to the the perfect gear mesh speed much more quickly and precisely than some wildly freewheeling turbo whizbang thing.

Note that Tesla's common 9:1 gear ratio is on par with an old fossil car in 2nd gear which is usually around 2.5:1 plus a 4:1 differential. Hence the similar performance to an equal HP/weight clunker in the 20-50 mph range of 2nd gear.

I don't know much about the 2-speed Roadster but I'd guess they were counting on all the advantages listed above to allow them to omit or downsize much of the conventional clutch and torque converter systems of a 6-speed. It's also possible that they underestimated the shock loads that the meshing gears would send back to the motor which has a bunch of brittle magnets poorly glued together (hence the need for things like carbon overwrapping).

 

[gearchruncher]

in other news, looks like Tesla just cranked up the plaid to 175mph in track mode.

15,700 RPM, only 3,100 RPM short of a 2012 Model S
It is really cool though. Except for the brakes. Did you notice a critical high brake warning after one 175 MPH stop? I guess that's why the track mode warns:

And all on Tesla timeframes of course:

 

[raptor5244]

This tech will quickly become the normal over the next few years as Tesla gets more competition and I bet in 5 years, 2.0 second 0-60's will be pretty normal. It's just not that expensive to do in an EV.

I agree, which makes me wonder what features manufacturers will focus on to appeal to enthusiasts moving forward. If we eventually see Honda Civic EVs in the 3 sec range, how much will someone want to pay for 2.5 sec? This 0-60mph game is basically getting to the point where no one will care anymore? I think it will come down to styling, interior, reliability, handling, range, customer service, aftermarket support, etc.

 

[Sam1]

15,700 RPM, only 3,100 RPM short of a 2012 Model S
It is really cool though. Except for the brakes. Did you notice a critical high brake warning after one 175 MPH stop? I guess that's why the track mode warns:
View attachment 752062

And all on Tesla timeframes of course:
View attachment 752061

dude 175 to zero emergency stop is no joke. one emergency stop on my m3p stealth blued the rotors really bad, and I had brake fade towards the end. Add 500 pounds and 30mph and those brakes are probably screaming like <insert whatever term here>

 

[gearchruncher]

dude 175 to zero emergency stop is no joke. one emergency stop on my m3p stealth blued the rotors really bad, and I had brake fade towards the end. Add 500 pounds and 30mph and those brakes are probably screaming like <insert whatever term here>

Well, a few things:
M3P and Plaid non-Track does 162- This is 13 MPH faster, not 30
They advertise this car as a 200 MPH car with only new wheels and tires. It should be safe if it's going to do that.
They drove a supposedly 100% stock (including brakes and tires) Plaid to a 7:35 Nürburgring lap time, which is way more punishing than a single 175 MPH stop with the brake warning coming on at about 40 MPH.

A note on energies:
175 MPH is 17% more energy than 162 MPH
200 MPH is 52% more energy than 162 MPH. They have WAY more energy to unlock to hit their advertised goal and they're already having issues.

Braking from 170 MPH to 70 MPH is exactly the same energy as 162 to zero, so lots of tracks hit these kinds of energies over and over on cars.

This is advertised as a 200 MPH capable (and thus safe car). If the brakes can't do one 200 MPH to zero stop, that's pretty iffy. I bet that they require their massive carbon upgrade ($20K) to actually get to 200 MPH, but that's lawsuit territory given they didn't list that at time of sale.

Of course, this is exactly why NHRA won't let a Plaid down a quarter mile without a chute, and Tesla isn't exactly proving that wrong given NHRA's whole concern with fast cars is brake systems and a Plaid can overheat in one stop.

 

[Sam1]

Well, a few things:
M3P and Plaid non-Track does 162- This is 13 MPH faster, not 30
They advertise this car as a 200 MPH car with only new wheels and tires. It should be safe if it's going to do that.
They drove a supposedly 100% stock (including brakes and tires) Plaid to a 7:35 Nürburgring lap time, which is way more punishing than a single 175 MPH stop with the brake warning coming on at about 40 MPH.

A note on energies:
175 MPH is 17% more energy than 162 MPH
200 MPH is 52% more energy than 162 MPH. They have WAY more energy to unlock to hit their advertised goal and they're already having issues.

Braking from 170 MPH to 70 MPH is exactly the same energy as 162 to zero, so lots of tracks hit these kinds of energies over and over on cars.

This is advertised as a 200 MPH capable (and thus safe car). If the brakes can't do one 200 MPH to zero stop, that's pretty iffy. I bet that they require their massive carbon upgrade ($20K) to actually get to 200 MPH, but that's lawsuit territory given they didn't list that at time of sale.

Of course, this is exactly why NHRA won't let a Plaid down a quarter mile without a chute, and Tesla isn't exactly proving that wrong given NHRA's whole concern with fast cars is brake systems and a Plaid can overheat in one stop.

Was comparing the car to mine at 145, not another plaid at 163. That's a 30mph difference, and also why I said "500 pounds more".

Tesla has already announced that they're selling a carbon brake kit for the car at some point, and the guys that physically caught the plaid brakes on fire after seven (or eight, can't remember) 100-0 stops, showed just how hard it is to stop this near 5000 pound car.

The reason nhra and most tracks or organizations won't allow it on the track without a chute is for liability and insurance purposes. Below a 10, or 150+ you need a chute (depending on the org and track). Insurance implements similar rules for my family's oval track. Break a rule they set and we let you get away with it, then something happens, the policy won't cover a claim and we would be financially responsible. Certain cages, certain types of braided cable around the catch fence, concrete walls a certain height, certain thickness with specific bumpers in areas where pedestrians are to deflect cars in a different direction, that's all determined by insurance. The organizations implement insurance rules for their own liability mitigation.

 

[gearchruncher]

Tesla has already announced that they're selling a carbon brake kit for the car at some point.

Tesla's also already announced that the car will do 200 MPH with only a tire and wheel upgrade.

The reason nhra and most tracks or organizations won't allow it on the track without a chute is for liability and insurance purposes.

Huh? What you basically said was that above that speed, a whole bunch of organizations agree it is good to have a backup. Are you seriously saying that if it wasn't for the evil insurance companies, NHRA would let you run a 200 MPH car without chutes and just go "your butt buddy!"

I mean, the reason insurance wants it is because it saves lives. I assume your family's track would set reasonable limits on safety even if there was no insurance company? The idea of "liability" is the very idea that you were irresponsible in allowing a clearly unsafe act to occur.

 

[Sam1]

Tracks, organizations, and the coverages they each have to use and follow guidance of, is a complex situation. Skipping those boring details, safety is a component of liability mitigation. So yes, an organization puts rules in place for liability, and safety is one of the components of that.

 

[Sam1]

Ignore my last few posts, drunk posting last night and I have no clue what I was even trying to say.

 

[dfwatt]

Makes sense, I just thought current transmissions can handle those torque loads. We see Dodge, GM and Chevy using ZF, Tremec, etc. supporting their high torque output models but as you mention they are probably dialing in a lot of torque management to save the drivetrain.

All this discussion about possible two speed transmissions is obviated by the flat horsepower curve of the Plaid. There is no advantage at all to a transmission if your horsepower curve is this flat and you are keeping the motor in the flat portion of the output. You're just trading RPM for torque or vice versa. Net gain of zero. Less true for other motors like what's in the model 3 and the earlier model S motor, where you can keep the motor close to peak HP, although the difference isn't great in those cases and you could argue that the extra complexity is just not worth it.

 

[raptor5244]

All this discussion about possible two speed transmissions is obviated by the flat horsepower curve of the Plaid. There is no advantage at all to a transmission if your horsepower curve is this flat and you are keeping the motor in the flat portion of the output. You're just trading RPM for torque or vice versa. Net gain of zero. Less true for other motors like what's in the model 3 and the earlier model S motor, where you can keep the motor close to peak HP, although the difference isn't great in those cases and you could argue that the extra complexity is just not worth it.

I agree 100% but at what cost though. Today this perfect power curve costs $130k but if a 2-speed transmission could yield similar performance benefits in say a Model 3 Performance for only $5k more would it make sense? In other words, if a 2-speed trans with optimized gearing could get the M3P to 60mph in 2.5 sec and down the 1/4 mi in 10 sec flat for only $5k more would you be interested? For a performance car that would see the track or drag strip I would take on the added complexity of an EV transmission assuming it keeps the price point in the $60-70k range.

Let's hope the Plaid powertrain technology eventually trickles down to affordable levels.

 

[tm1v2]

I agree 100% but at what cost though. Today this perfect power curve costs $130k but if a 2-speed transmission could yield similar performance benefits in say a Model 3 Performance for only $5k more would it make sense? In other words, if a 2-speed trans with optimized gearing could get the M3P to 60mph in 2.5 sec and down the 1/4 mi in 10 sec flat for only $5k more would you be interested? For a performance car that would see the track or drag strip I would take on the added complexity of an EV transmission assuming it keeps the price point in the $60-70k range.

Let's hope the Plaid powertrain technology eventually trickles down to affordable levels.

I would be very, very surprised if the extra top-end from the new S/X adds any more additional cost to Tesla, than Porsche's 2 speed does for them. Remember the LR/base S seems to have the same improvement, just with less overall power.

Put another way, the S Plaid is much faster and much cheaper than a Taycan Turbo S. Sure Porsche is known for huge profit margins, but so is Tesla these days. There's nothing to indicate that Porsche's 2 speed is in any way a cheaper solution, especially when it's still the slower car!

Edit: I'm sure for some extremely high speeds, a multispeed transmission would still be worthwhile. Like if you wanted to race Bugattis to 250mph. Maybe it would be useful on the Bonneville salt flats. Not sure where else I could even do such a thing. I think even for most driving enthusiasts and racing scenarios (drag strips, road courses), multispeed EV transmissions are completely obsolete now.