Should Tesla make a “Track Edition” Roadster?

[Cloxxki]

Actual tyre pressures in F1 have gone up a good bit as there is just one supplier now paying a lot for the privilege and monopoly, doesn't want tyres blowing up on top of the safety aspects. Pirelli sets the minimum pressures for the events and can adjust those as they deem necessary. Without it, teams would go much lower and some would suffer blow-ups or disastrous performance drop.

"Tesla knows what it's doing"
They are successful at what they do, but lots of details show that really they are just winging it. The Track Mode thing shows this. They were all ready to unveil it and then by chance an actual pro driver got to try it. Tesla ended up hiring him to actually get the system up. Ik could go on all day on how Tesla fails at many things (forced to develop OTA updates) which other brands just get right first time, all the time.
Also, fans often project a larger scope to Tesla projects. "OMG the 200kWh Roadster is totally going to blow away the other hypercars on cornering speeds. Because, they did what no-one did for BEV's."

We can guess for another 2 years probably. Either Tesla has some higher density batteries on the way, or they are going to stuff the little car with the cost optimized slow cells of the Model 3.
In the mean time, a Chinese uni spin-off start-up is starting production of initially 100MWh of solid state battery cells, 400Wh/kg. Let's say, Tesla ordered a lot of those. Compared to current 2170 cells which seem to still be well below 300Wh/kg (please someone weigh and full discharge some...), a very significant improvement. It still wouldn't make for a 200kWh lightweight car, though.

 

[Peteski]

Actual tyre pressures in F1 have gone up a good bit as there is just one supplier now paying a lot for the privilege and monopoly, doesn't want tyres blowing up on top of the safety aspects. Pirelli sets the minimum pressures for the events and can adjust those as they deem necessary. Without it, teams would go much lower and some would suffer blow-ups or disastrous performance drop.

I'm not surprised to hear that. In my F1 era as a race engineer (2000-2009) we had a lot of heated debates about tyre pressures. The tyre suppliers were pushing for conservative higher pressures for safety and the teams were pushing for maximum performance (lowest pressure you could dare to run!). It didn't help (from a safety perspective) that there was fierce competition between Bridgestone and Michelin at that time. There was rumour of some dubious stuff going on with "active" tyre valves too in that era, although I never saw it personally.

From a pure performance perspective, tyre grip used to fall off rapidly with pressure increase. So it was always a critical parameter to get right and a very fine line between performance and safety. Hence quite a few catastrophic tyre failures during that era!

I bet the biggest problem Pirelli face today is policing the teams as it would be an obvious performance advantage to run below the "safe" minimum pressures enforced by the supplier.

 

[Cloxxki]

I bet the biggest problem Pirelli face today is policing the teams as it would be an obvious performance advantage to run below the "safe" minimum pressures enforced by the supplier.

It indeed took a few attempts to properly set measuring timing and protocol vs heat present in tyres and wheels.

 

[Peteski]

Also, fans often project a larger scope to Tesla projects. "OMG the 200kWh Roadster is totally going to blow away the other hypercars on cornering speeds. Because, they did what no-one did for BEV's."

We certainly see a lot of that on this forum and I can understand the hype. But so far all the evidence points to a great looking, but seriously heavy, drag strip king. Certainly nothing to suggest it will have amazing handling unless we are counting on the "Space X" package to compensate for the weight, which evidently some people are. Personally I'm extremely sceptical about the practicalities and safety aspects of it and wouldn't be at all surprised to see a major back-pedal there or a simplified version just to further maximise straight line acceleration. If this car is seriously going to rely on thrust boosters during high G cornering then I fear it will end badly. But it's their ball to play with and they may well end up down some rabbit hole as they have with some of their other more ambitious projects. There's a fine line between innovation and madness and sometimes Tesla overstep that line a little. I guess that's just the nature of the game.

 

[Peteski]

It indeed took a few attempts to properly set measuring timing and protocol vs heat present in tyres and wheels.

Yes, it's a very dynamic parameter to measure and open to plenty of potential abuse.

 

[Brando]

@Peteski

SpaceX package - can air jets be used to create low pressure under the car? Accelerate air going under the car?
Computer controlled downforce over most of the car would have obvious advantages.
This is the only "idea" my little brain can imagine and would fit my impression of Elon "out of the box, back to basic physics thinking".
Can hardly wait to see what the SpaceX option actually is.

PS - mean time www.uniti.earth continues to progress to what might be the next generation "Volks Wagon Beetle". And the Chinese/Indians may well surprise - Wall St./US auto.

interesting and inspiring talks from Tokyo car design forum -
India, China, Asian: trends & strategies of auto market
- sadly, another example of how management undermines its engineers/designers, in my opinion - concepts are astounding, they just won't build them. BUT competition and actual survival of their companies MIGHT inspire management to listen to these designers - we shall see. You'll enjoy the talks.

 

[Peteski]

@Peteski

SpaceX package - can air jets be used to create low pressure under the car? Accelerate air going under the car?
Computer controlled downforce over most of the car would have obvious advantages.
This is the only "idea" my little brain can imagine and would fit my impression of Elon "out of the box, back to basic physics thinking".
Can hardly wait to see what the SpaceX option actually is.

PS - mean time www.uniti.earth continues to progress to what might be the next generation "Volks Wagon Beetle". And the Chinese/Indians may well surprise - Wall St./US auto.

interesting and inspiring talks from Tokyo car design forum -
India, China, Asian: trends & strategies of auto market
- sadly, another example of how management undermines its engineers/designers, in my opinion - concepts are astounding, they just won't build them. BUT competition and actual survival of their companies MIGHT inspire management to listen to these designers - we shall see. You'll enjoy the talks.

SpaceX package - I'm not an aerodynamicist, but in F1 exhaust blown diffusers were often used to enhance the diffuser airflow. So they could perhaps use air jets in a similar way, interacting with a rear diffuser to maximise downforce. Presuming the system can provide the volume of air required (I have no idea on that point), it would be more controllable than an exhaust blown diffuser which is obviously passively dependent on engine speed and throttle. But the question is why bother when you could simply use active aerodynamic devices to increase downforce in cornering without adding high speed drag? So personally I expect the SpaceX package to be more of a direct thrust vectoring system. Certainly very interesting, but probably just a novelty feature rather than a game-changing concept - like much lighter batteries would be!

The Chinese EV scene looks like it could be very interesting in the next decade. Thanks for the links, I'll check them out with interest!

 

[Cloxxki]

Would it be preferable to use air thrust for downforce or for anti-centrifugal force?
Yes, having the thrusted air interact with a diffuser or spoiler might give a lot of downforce for the drag.
But then, you could also have a vertically placed airfoil and generate lateral lift that way, NOT sending the force through the tires, but reducing the net mass the tires experience.

I've tried to find the kinds of thrust and duration and compression efficiencies we should be expecting for the SpaceX package, but I've come up blank. I can't even ballpark it. Merely pointing the trust in the right directions while accelaring, braking and cornering might help many seconds per GP lap, or be immesurable.

I suppose if you're going to bring downforce into the equation to corner faster, you may as well build a fan car and let it help cool the batteries or something. Downforce will after all be most needed in times when heat management is an equal priority.

My idea of vertical airfoils is not new but we don't see more of it nowadays than as a passive shark fin. Imagine the fin were bigger and could be hydraulically deformed from a thin air splitter to a laterally operating wing either way. There is hardly a limit to how many fins could be placed, even on the sides of a car. They could even retract on straight lines. And offer maximum drag under braking by turning into sail.

 

[Peteski]

Would it be preferable to use air thrust for downforce or for anti-centrifugal force?
Yes, having the thrusted air interact with a diffuser or spoiler might give a lot of downforce for the drag.
But then, you could also have a vertically placed airfoil and generate lateral lift that way, NOT sending the force through the tires, but reducing the net mass the tires experience.

I've tried to find the kinds of thrust and duration and compression efficiencies we should be expecting for the SpaceX package, but I've come up blank. I can't even ballpark it. Merely pointing the trust in the right directions while accelaring, braking and cornering might help many seconds per GP lap, or be immesurable.

I suppose if you're going to bring downforce into the equation to corner faster, you may as well build a fan car and let it help cool the batteries or something. Downforce will after all be most needed in times when heat management is an equal priority.

My idea of vertical airfoils is not new but we don't see more of it nowadays than as a passive shark fin. Imagine the fin were bigger and could be hydraulically deformed from a thin air splitter to a laterally operating wing either way. There is hardly a limit to how many fins could be placed, even on the sides of a car. They could even retract on straight lines. And offer maximum drag under braking by turning into sail.

Interesting thoughts indeed. Off the top of my head (I haven't given it any great thought) I think there are several reasons why we don't see much in the way of "active" aerodynamics:-

1. It was traditionally banned in most high level racing fomulae (although recently there are some examples)
2. Safety concerns - a sudden failure of an active downforce/lateral thrust system could lead to catastrophic consequences
3. Cost - although probably less of a factor today with cheap processors etc.
4. Very niche market

But as you say, ignoring the above, with a free reign and no rule book you could probably push this a long way. The Porsche 919 Evo is a good example of how much faster you can potentially go without regulations holding you back. Imagine a totally unrestricted F1 formula in the modern era!

 

[jaguar36]

I think there are several reasons why we don't see much in the way of "active" aerodynamics

There are a ton of cars with active aero. Porsche's have had retractable spoilers for years. Bugatti's have air brakes. The 488 has an active rear diffuser. The 458 Speciale had moveable flaps front and rear. Heck even Tesla had a pop-up spoiler on the X for awhile. The only reason you don't see more of it is that it makes the most difference at extra-legal speeds and its banned from almost every racing series.

 

[Peteski]

There are a ton of cars with active aero. Porsche's have had retractable spoilers for years. Bugatti's have air brakes. The 488 has an active rear diffuser. The 458 Speciale had moveable flaps front and rear. Heck even Tesla had a pop-up spoiler on the X for awhile. The only reason you don't see more of it is that it makes the most difference at extra-legal speeds and its banned from almost every racing series.

That's true, but I was thinking somewhat beyond these relatively simple and mostly very conservative applications. You could push this a lot further than any manufacturer currently chooses to do, but I think the reasons why they hold back are fairly clear. It will be interesting to see where Tesla go with the SpaceX package, but they are IMO stepping into a minefield if they push it too far. At the end of the day it's a road car they are producing here and it needs to be reasonably foolproof.

 

[Brando]

If Tesla can get extra down force for 2 seconds just for acceleration that may be enough. Other racing oriented companies then have a good reason to innovate. Suspect Tesla wants to work on autopilot vs racing.

PS - 918; Ferrari; McLaren search for on YouTube interesting comparison by Harris and two other people.

 

[Cloxxki]

If Tesla can get extra down force for 2 seconds just for acceleration that may be enough. Other racing oriented companies then have a good reason to innovate. Suspect Tesla wants to work on autopilot vs racing.

PS - 918; Ferrari; McLaren search for on YouTube interesting comparison by Harris and two other people.

Downforce from standstill? I'm not positive that's the most efficient way to achieve additional acceleration. Add low speed, the thruster would neeed to be chimney style. Might as well use an aft thruster and get drive that doesn't require a tyre contact patch as a medium of transfer.
There have been steam powered drag racers that were much faster than you might expect.

Would complementing the cold air with water help, much like a water rocket, or just pose needless mess and losses?

 

[Peteski]

Downforce from standstill? I'm not positive that's the most efficient way to achieve additional acceleration. Add low speed, the thruster would neeed to be chimney style. Might as well use an aft thruster and get drive that doesn't require a tyre contact patch as a medium of transfer.
There have been steam powered drag racers that were much faster than you might expect.

Would complementing the cold air with water help, much like a water rocket, or just pose needless mess and losses?

I agree, if you wanted to beat the traction limited 1.9 sec 0-60 time, then a direct thrust system is the way to go and I'm half expecting the SpaceX package to end up being something relatively simple like this and it could be very effective as an instant power booster off the line. Could also be used in reverse for extra braking force. We can expect some spectacular crashes though if used inappropriately!

 

[Cloxxki]

Downforce from standstill? I'm not positive that's the most efficient way to achieve additional acceleration. Might as well use an aft thruster and get drive that doesn't require a tyre contact patch as a medium of transfer.
There have been steam powered drag racers that were much faster than you might expect.

Would complementing the cold air with water help, much like a water rocket, or just pose needless mess and losses?

I agree, if you wanted to beat the traction limited 1.9 sec 0-60 time, then a direct thrust system is the way to go and I'm half expecting the SpaceX package to end up being something relatively simple like this and it could be very effective as an instant power booster off the line. Could also be used in reverse for extra braking force. We can expect some spectacular crashes though if used inappropriately!

Tesla drivers don't need a SpaceX package in an next level sports car. There are plenty well documented cases of criminally reckless driving to offset the otherwise very safe cars' record.

A lot would depend on how fast the compression can work. The battery being so large could offer a lot of power to it as needed. A well built compressor might take more energy than the battery can accept in terms of regen. Braking from high speeds, and this baby will hit 200mph 1-3 times around a GP track, there will be more than the regen can handle. If some of it could somehow reach the compressor directly (I doubt it) that would be great for on-track efficiency.
Set up to provide lateral trust, no aero tricks for a hot lap, it might do more than ttorque vectoring can. In stead of slowing down a wheel or two to balance the car, just add a bit of thrust to go faster than the tyres are able to grip. Indeed not something to rely on for too long as you'll just run wide and/or crash once the tank runs out.

Could the cold air also hyper-cool the battery, motors and invertors, even brakes? Nah, let's focus on thrust.
Thruster being simple and light, air lines light, thrusters can be placed around the car to aid performance. I can see it eventually be used as a safety feature for driving on slippery roads. And then be abused by drivers who trust it too much causing horrific crashes.

Tesla's meaning of "performance" being mostly off the line, the very first few seconds, even a very limited capacity air thruster, given enough top end thrust, could actually make put dent into 0-60 times.
Let's take a random number, 500Wh (like a heavily doped 100kg cyclist, over a full one hour time trial). A decent electric supported bicycles's battery.
If this battery were a supercapacitor (a large bank of them), that energy could easily be released in 2 seconds. 900kW, almost doubling the New Roadster's peak power. Even 5 second for a max burst would offer 360kW.
If thrust were in that ball park...360kW is like a 500hp car with a perfect transmission. So on that power alone you could have a heavy car keep up with a really nice Porsche Panamera, even Tesla Model S.
Such thrust ON TOP of the ~1MW the New Roadster simply cannot get to the road before it reaches >100mph with sure hurry it up significantly. Plaid moniker worthy.

But, the cold thrusters may well offer powers of magnitude less capacity and power than I just showed. I wish we could hear from someone who knows this tech, how much a desk top sized system might be able to do.

 

[gowthamn]

Elon said there would be 10 thrusters. So they should be pointing in all directions for use in acceleration, braking and cornering.

 

[Peteski]

Elon said there would be 10 thrusters. So they should be pointing in all directions for use in acceleration, braking and cornering.

It will certainly be "interesting" but not the kind of thing Tesla should be wasting their time and effort on given where they are right now and their overall "mission".

 

[tonybelding]

If it was up to me, I would have just taken the Model 3 Performance "skateboard" and slapped a carbon fiber 2+2 convertible body on that and called it done. Tesla Firebird. Because I'm lazy that way. Also because I don't feel a need to set a whole list of world records or lay a hardcore smackdown on gas cars.

But it wasn't up to me. The new Roadster isn't the car I ordered; it's the car Elon Musk ordered, and I think we all know him pretty well by now. So, it'll cost what it costs, weigh what it weighs, and perform how it performs. Nobody outside of Tesla will know for sure until it ships, then we'll all find out. Pretty sure I'll still want one regardless!

 

[J1mbo]

SpaceX package - I'm not an aerodynamicist, but in F1 exhaust blown diffusers were often used to enhance the diffuser airflow. So they could perhaps use air jets in a similar way, interacting with a rear diffuser to maximise downforce. Presuming the system can provide the volume of air required (I have no idea on that point), it would be more controllable than an exhaust blown diffuser which is obviously passively dependent on engine speed and throttle. But the question is why bother when you could simply use active aerodynamic devices to increase downforce in cornering without adding high speed drag? So personally I expect the SpaceX package to be more of a direct thrust vectoring system. Certainly very interesting, but probably just a novelty feature rather than a game-changing concept - like much lighter batteries would be!

The Chinese EV scene looks like it could be very interesting in the next decade. Thanks for the links, I'll check them out with interest!

Picking up on this, I think we may have seen an early iteration of the SpaceX package on some of the Plaid mules recently... that rear diffuser...

If you watch the testing video (here), IMO the fan noise from the blue is significantly louder than the red.

 

[Brando]

If it was up to me, I would have just taken the Model 3 Performance "skateboard" and slapped a carbon fiber 2+2 convertible body on that and called it done. Tesla Firebird. Because I'm lazy that way. Also because I don't feel a need to set a whole list of world records or lay a hardcore smackdown on gas cars.

But it wasn't up to me. The new Roadster isn't the car I ordered; it's the car Elon Musk ordered, and I think we all know him pretty well by now. So, it'll cost what it costs, weigh what it weighs, and perform how it performs. Nobody outside of Tesla will know for sure until it ships, then we'll all find out. Pretty sure I'll still want one regardless!

You had so much more input on the mid-engine Corvette, right?
I read about it since the 1970s. Only took 50 years.
Who makes the better dictator? Elon or GM/Wall St. managers?

funny