+1
Maybe make the prize for the winner be one of the of the test drive vehicles ... with the top speed limiter "curiously broken".
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Model S Performance vs BMW M5
- Thread starter CapitalistOppressor
- Start date
Maybe make the prize for the winner be one of the of the test drive vehicles ... with the top speed limiter "curiously broken".
Not much faster than it currently does (maybe 1-2 mph). At the speeds the motor is running bearing heat will be a significant problem. The true solution is to change the gearbox ratio. You would lose some acceleration but you would get a lot of top speed. This ratio would obviously be different for each track, such that on an 'ideal' lap you would hit dropping torque at the top speed of the track.
spatterso911
P100DL - Raven
There are a few compromises for both. I don't think most reviewers will be forgiving of the comfort setting on the M5, and most reviewers will slam the Model S for steering input. I will revisit this topic after my test drive and tell you what my thoughts are.
If one is looking for value-for-money on a performance sedan and straight line acceleration is your itch I got yer car right here: http://www.cadillac.com/cts-v-luxury-sedan.html
Sorry, I know that's not the comparison we're making here so I won't take it any farther.
As for the Nurbergeringerishelfthingamajig... http://green.autoblog.com/2012/06/29/audi-r8-e-tron-sets-new-electric-record-with-8-09-099-time-at-n/ I guess all we need to do is remove that pesky speed limiter!
Sorry, I know that's not the comparison we're making here so I won't take it any farther.
As for the Nurbergeringerishelfthingamajig... http://green.autoblog.com/2012/06/29/audi-r8-e-tron-sets-new-electric-record-with-8-09-099-time-at-n/ I guess all we need to do is remove that pesky speed limiter!
W8MM
R1.5 #325 + Mdl S #01380
Aerodynamic drag increases with the square of speed. 10% more speed needs 20% more umph to get there. 41% more speed DOUBLES the power required.
Electric motor torque (umph) is proportional to the current being forced through it. When an electric motor spins, it creates an opposing voltage (back EMF) that has to be overcome so as to continue to force the current. At some RPM, the electric motor generates so much back-EMF that the power supply can't supply enough current at a high enough voltage to make ANY current flow through it, thereby becoming the top rotational speed theoretically possible. But please note, at the top rotational speed, there is vanishingly small torque available to push the car through the air.
So, there is some crossing of the drag power vs. speed curve and the motor's torque vs. speed curve that sets the maximum speed obtainable by the car. A different gear ratio can change the possible top wheel speed of the drive train (in a vacuum), but the lowering of the motor's torque to the wheels (to overcome drag) by the same ratio makes finding the right point a matter of mathematics.
As it turns out, the top speed is generally limited by the power output of the motor as long as the gear ratios are chosen optimally. One can always go slower by a non-optimal choice, but I don't think Tesla is dumb enough to chose a sub-optimal gear configuration. QED, the "speed limiter" is likely Mother Nature, herself.
An electric motor capable of 400hp can easily push a Model S past 130mph. It would probably be around the M5 top speed (due to significantly less drag) of around 180mph. 200 HP can push my GTI with roof rack 135 MPH (speed limiter) somewhat easily. Heck my 130hp Dodge Neon could go 110mph.
In general the way induction motors work is constant torque up to max HP. Then constant HP with falling torque. Finally an increasing falling off of both torque and HP.
If you change the gear ratio you keep the exact same motor curve. But your torque to the drive wheels is less, which means less acceleration. Your power goes up more slowly (with speed of vehicle) which allows you to have higher power later in the band which keeps your car moving.
The roadster sport hits peak power at 4400-6000 rpm (http://www.teslamotors.com/roadster/specs). But doesn't hit peak speed until 14,000 rpm at 125 mph. This means it's peak power is around 50-55 mph. It drops as you go beyond that. If it had peak power at 120mph it could easily go beyond that speed.
The Model S is geared such that it maximizes acceleration over real world road speeds. Which means the lowest gear ratio while still achieving an acceptable top speed (120-130mph).
Tesla basically only has 2nd gear. You get great acceleration until your engine starts dropping power around the red line. It has nothing to do with peak power.
You hit the nail on the head on this one.
Short of only comparing the cars at tracks where the top speed will be below 100mph (Summit Point Jefferson circuit in WV comes to mind) this comparison of track prowess is pointless. I have raced cars and motorcycles for the better part of 12 years and top speed (track dependant, of course) has a huge impact. I race motorcycles and my GSX-R750 will repeatedly get destroyed by 1000cc bikes on topend. Depending on rider, I can hang in the corners but once we hit a straight the topend difference is the deal-breaker. My bike can only do 174mph and litre bikes can get up to 190+mph (and get there quicker).
PV4EV
Member
If you really want a car that can, in the extreme, be driven by a suitably skilled driver with big enough balls to do The Ring in under 7mins 30s, and provide the odd 190mph blast once a day (like we all can), and want 1,000's of highly evolved mechanical moving parts that are, despite 100+ years of refinement, still only 20% efficient, and want to continue to waste what's left of the planets fossil fuel resources, and want to be fleeced senseless by ridiculous running costs, then do NOT buy the Model S. Go get that M5, its still a free world, no one is forcing you to accept either car !!
But if in the real world of spending 99.9% of your time below 100mph, you want an equally comfortable car, that’s near silent, with searing mid range acceleration to equal the M5, and sub 100mph handling that’s in a class of its own, and, crucially, can be charged from Sunlight / Wind etc, and has less than 1/10th of the running costs … then get a Model S.
After 3 Porsches, 4 Ferraris, 2 TVRs, 3 Lotus'es, 4 Group B rally cars, 2 Astons, 2 RS6's, 2 Quattro's, various track cars, 1 BMW (!) and dozens of hot hatch backs etc, and around 2,000+ miles in a BMW M5 V10 …. I just do not want any more ICE cars, no matter how brilliant they might be round the ring.
After 1 Tesla, I doubt I will ever buy another ICE car ever again. I just don’t see the point of them anymore.
But if in the real world of spending 99.9% of your time below 100mph, you want an equally comfortable car, that’s near silent, with searing mid range acceleration to equal the M5, and sub 100mph handling that’s in a class of its own, and, crucially, can be charged from Sunlight / Wind etc, and has less than 1/10th of the running costs … then get a Model S.
After 3 Porsches, 4 Ferraris, 2 TVRs, 3 Lotus'es, 4 Group B rally cars, 2 Astons, 2 RS6's, 2 Quattro's, various track cars, 1 BMW (!) and dozens of hot hatch backs etc, and around 2,000+ miles in a BMW M5 V10 …. I just do not want any more ICE cars, no matter how brilliant they might be round the ring.
After 1 Tesla, I doubt I will ever buy another ICE car ever again. I just don’t see the point of them anymore.
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W8MM
R1.5 #325 + Mdl S #01380
I think we agree on the physics, I just think that Tesla's "real world" gear choices are not very far off (if at all) from the best they could do to minimize Nordschleife times. The Model S does not, in fact, have its horsepower peak in the upper ranges of RPM the way ICE motors do; it's upside down and backwards. "Hot rodding" electric cars is a bit more complicated than it might seem and anti-intuitive if one's data points are all from the ICE motor world.
Well said! I've never owned a sports car before coming from minivan (hey, don't judge. Can't turn down a free car when you are 16) to a Volvo to a Jetta then the Roadster. Even then, I doubt I'll ever buy another ICE. Only case would be if I moved somewhere and had some massive commute with no ability to recharge. I doubt I'll ever want to live over 120 miles from work so that's not really an issue.
I wouldn't bet a ton of money on the MSp vs M5. I fully agree that the M5 is an amazing machine which I lust after, my main point is that the M5 is an ICE vehicle which has fundamental performance limitations and advantages. Everyone focuses on 0-60 times, but that metric favors an ICE vehicle, because an ICE vehicle is like a continuously winding windup toy.
On launch you can wind it up and store all kinds of energy in the drive train then BOOM! But once the vehicle is moving, its much more difficult to keep it wound up. In fact, it's natural state is to be unwound, and once you unspool that spring you have all kinds of kinetic issues involved in winding it back up.
A small sports car can deal with this issue much better than a big performance sedan. It takes relatively little kinetic energy to spool up a 2 liter twin turbo using ultralight parts in its drive train. A big sedan uses a big engine to get similar acceleration numbers, but if you unspool it it takes dramatically more energy to spool it back up.
Model S doesn't really have those issues. It doesn't have to fight inertia in the internal components of its engine and doesn't need to wind up its drive train through a transmission. Torque response is primarily limited by how quickly you can depress the pedal. It is entirely possible that MSp isn't quite there yet in terms of overall dynamic performance, but based on what we do know there is reason to believe it wont embarrass itself.
He will own you on a drag strip. The point is that its entirely possible you have the advantage in a turning race
Model S apparently doesn't have the same heating issues above 70MPH that the Roadster had. I've seen numerous reviews stating that Model S is accelerating through 100 with authority. MotorTrend specifically compared it to a "big gasser" in that respect. We badly need instrumented tests for actual data, but I suspect that based simply on basic physics of transmissions vs direct drive that Model S can't match a modern gas vehicle in 100+MPH acceleration.
No doubt about it. But dynamic performance is more than that, and it will make a statement to be able to say that Model S is the fastest sedan in the world on a tight road course. Most of the "fun" that people can actually legally access is represented in that type of comparison.
It would be a bad idea for the engine. And performance would be terrible. Top end performance will require a transmission.
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