Agreed, but they don't need to be. Remember, the magic number here is ~1.4G, for a 1.9s 0-60. The Pilot Sport Cup 2 – a track-friendly R-compound tire used in the webcast car and in the videos – can pull close to that on a skidpad (i.e. less than optimal conditions), meaning the grip is there.
> I think it's straining credulity to believe that an electronic traction control system is going to outperform them to such a huge degree.
Launch control and traction control can make several tenths of seconds of difference, which is critical when you're talking about sub-2s times. Also, traction control can keep the car on the cusp of slip the entire run to 60MPH, which is critical in a car that has a completely flat torque curve and probably enough torque to break the wheels loose at any speed (which is not true for F1 cars).
I also suspect that the Roadster has active damping – another technology disallowed in F1 – meaning that the duration of contact with the road can be maximized. This is important if the road surface isn't glassy-smooth.
> This car also looks to weigh around double what an F1 car will weigh
That doesn't help it at all in cornering, but in a straight line, the increased weight of the car will help it launch even better since it'll increase the traction on the drive wheels (equivalent to downforce at speed).
> Gear changes: F1 gear changes take about 8 milliseconds. A road-going automatic gearbox is definitely not going to beat this.
There's no gearbox to speak of; the wheels are direct-drive. To be fair, this won't contribute significantly to faster 0-60 times, but the gearbox exists to compensate for some less-than-ideal characteristics of an ICE, namely uneven power delivery and physical limitations on peak RPMs. An electric motor has none of these problems.
> Agreed, but they don't need to be. Remember, the magic number here is ~1.4G, for a 1.9s 0-60. The Pilot Sport Cup 2 – a track-friendly R-compound tire used in the webcast car and in the videos – can pull close to that on a skidpad (i.e. less than optimal conditions), meaning the grip is there.
That's lateral grip, which isn't the same at all. Longitudinal grip, which is what's important here, is very different. There's a lot of clever things you can do to increase lateral grip, such as wheel camber, that don't really apply to purely longitudinal grip, so I'm not sure this is valid.
> I also suspect that the Roadster has active damping – another technology disallowed in F1 – meaning that the duration of contact with the road can be maximized. This is important if the road surface isn't glassy-smooth.
But it has to have (comparatively) extremely soft road-going suspension. I really doubt that no matter how smart the active damping is that it will compare with race springs and dampers. Le Mans cars have all these active damping tricks, traction control, along with slick tires, low weight, very high power:weight ratios, skilled drivers, etc, etc, etc and they still don't get to 60 that quick.
That's an excellent example actually - the Porsche 919 Hybrid LMP1 car has a 0-60 of 2.2 seconds, despite electric power, FAR less weight, FAR better tires and drivetrain [0]. There is just no way you can make a road car that's faster than an LMP1 hybrid. If you can, maybe you can put a roll-cage in and take it to Le Mans.... but I doubt it.
> That doesn't help it at all in cornering, but in a straight line, the increased weight of the car will help it launch even better since it'll increase the traction on the drive wheels (equivalent to downforce at speed).
Weight increases the grip, but it also increases the amount of grip you need - you need more power to maintain the same acceleration, and this power needs to be transferred to the road. I'm not an expert, but AIUI, increased grip due to weight scales linearly, whereas the increase in power required (and thus the increase in grip required) scales geometrically, thus weight is counterproductive in getting you to 60mph faster. I could be wrong about this though - as always I'd be happy to be corrected by someone with more knowledge!
> That's lateral grip, which isn't the same at all. [...] There's a lot of clever things you can do to increase lateral grip, such as wheel camber, that don't really apply to purely longitudinal grip, so I'm not sure this is valid.
Camber isn't a magical trick to get more grip; it's a way to restore grip that would otherwise have been lost because of uneven tire loading in a corner. In a straight-line drive situation, the load is already ideal; the contact patch is the maximum size and fairly evenly distributed across the width of the tire.
> There is just no way you can make a road car that's faster than an LMP1 hybrid.
Indeed, it's currently impossible to make an all-electric race car that can compete with an ICE or hybrid race car in general race conditions, mostly because of the limitations of the energy storage. If the goal is just for a road car to beat a hybrid LMP1 (or even F1) car in a drag race though, as is the case here, I think that's much more doable. The ICE is really the weak link there.
> Camber isn't a magical trick to get more grip; it's a way to restore grip that would otherwise have been lost because of uneven tire loading in a corner. In a straight-line drive situation, the load is already ideal; the contact patch is the maximum size and fairly evenly distributed across the width of the tire.
Mostly. But only mostly. Tire grip is actually really, really, really complex however, and this is one of the places where a simplistic model breaks down really badly.
If we were able to model tires with simple newtonian physics, then no car would be able to hold more than 1g in a corner, as at that point the force sideways would be more than the force of gravity holding it to the road. Manifestly this is not actually the case.
Tire grip through a corner is more than just coefficient of friction against a surface. There's a lot of complicated things that happen, but the one I'm going to very lightly cover here is that when you go around a corner your tires deform slightly. The sidewall of the tire is pulled out of place, and at the maximum cornering speed of a tire, it will actually be slipping slightly (which can be heard as tire squeal). Cambering the tire corrects for uneven loading, but it also changes the sidewall stress profile, and thus affects the way the tire deforms under lateral load.
> AIUI, increased grip due to weight scales linearly, whereas the increase in power required (and thus the increase in grip required) scales geometrically
The high-school physics model of grip has them both linear, but more sophisticated models may show a difference.
(Interestingly, more mass on a vehicle does help when it is towing something heavy.)
> namely uneven power delivery and physical limitations on peak RPMs. An electric motor has none of these problems.
Electric motors do actually have an uneven response at different RPMs (in the form of back-emf losses). I worked for a while with an electric car team in university, and we used a mechanical system to adjust the stator position and tune the motor for different RPMs. I’m not sure what Tesla is doing to address this (could be mechanical or solid state), but you definitely can’t just keep dumping more power into a motor and expect it to get correspondingly faster, not even as a reasonable approximation.
Traction control has been banned in F1 since 2008, so this severely limits how quickly they can start from a standstill. The tires themselves certainly have enough grip to handle the acceleration; F1 cars routinely hit several lateral Gs in cornering (though with the help of downforce), well exceeding the ~1.4G required to accelerate to 60 in 1.9s.
Horrendously-written and incoherent rant. I didn't get anything out of that other than the fact that the author, for reasons unknown, really doesn't like iOS 7.
I think the piece is bad because it has not structure. Ie it's a train of thought that is difficult to follow. It's as if you wrote down shorthand notes during the presentation and then shuffled them around and dumped them in a document instead of actually writing a piece.
Instead i'd write it as: Thesis / Points that support it / Conclusion. Like, you know - the way writing is taught in school.
God, yes. It frustrated me so much that I ended up just copying the data into JS arrays and generating my own charts using the Google Visualization API.
Well, the law is on her side, since her listing is owner-occupied and thus does not qualify as a vacation rental. Only vacation rentals need a business license.
Agreed, but they don't need to be. Remember, the magic number here is ~1.4G, for a 1.9s 0-60. The Pilot Sport Cup 2 – a track-friendly R-compound tire used in the webcast car and in the videos – can pull close to that on a skidpad (i.e. less than optimal conditions), meaning the grip is there.
> I think it's straining credulity to believe that an electronic traction control system is going to outperform them to such a huge degree.
Launch control and traction control can make several tenths of seconds of difference, which is critical when you're talking about sub-2s times. Also, traction control can keep the car on the cusp of slip the entire run to 60MPH, which is critical in a car that has a completely flat torque curve and probably enough torque to break the wheels loose at any speed (which is not true for F1 cars).
I also suspect that the Roadster has active damping – another technology disallowed in F1 – meaning that the duration of contact with the road can be maximized. This is important if the road surface isn't glassy-smooth.
> This car also looks to weigh around double what an F1 car will weigh
That doesn't help it at all in cornering, but in a straight line, the increased weight of the car will help it launch even better since it'll increase the traction on the drive wheels (equivalent to downforce at speed).
> Gear changes: F1 gear changes take about 8 milliseconds. A road-going automatic gearbox is definitely not going to beat this.
There's no gearbox to speak of; the wheels are direct-drive. To be fair, this won't contribute significantly to faster 0-60 times, but the gearbox exists to compensate for some less-than-ideal characteristics of an ICE, namely uneven power delivery and physical limitations on peak RPMs. An electric motor has none of these problems.