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A pretty good visual.....


Zathrus~SPARTA~
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OK... yes that does demonstrate pretty well visually at how powerful the Tesla is.........

 

 

I still find myself explaining to guys that electric motors produce 100% torque instantly.... combustion engines cannot do that.

Many still get burned by these trying to race them.

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I drive into London most days and on the main road in there was a garage selling old classics really beautiful cars worth an absolute fortune it's to be the new Tesla garage opening soon

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Tesla's can't beat everything, except for the first few feet, where the instant torque plays its part. Ultimately acceleration is limited by traction.

 

 

Here is a video explaining the potential fastest acceleration time to 60 mph for street cars on street tyres. He works backward using the fastest deceleration time to arrive at the figure.

 

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Well yes this is always an issue... traction. In that first video where the GTR beats the Tesla... the GTR properly warmed up his tires... the Tesla did not. The Tesla had nasty tire slip for what appears the first half of the run... The GTR had very little if any tire slip. Having the car balanced properly on the axles front to rear + warming up the tires will give you maximum traction and acceleration.

For some reason that Tesla chose to run cold tires... which will always slip more easily cold than if heated up.

 

At local drag racing parks, really serious guys will actually bring a set of drag racing "slicks" to the track on separate wheels in the trunk (that's American for "boot" in the UK) of a 2 wheel drive muscle car.

But many of the new "muscle cars" are all wheel drive... shelling out the cash to have a separate set of wheels with "drag racing slicks" on them is very expensive so few do so... for one thing.. now you must tow something to haul them as 4 will not fit in even the largest trunks.

 

There are some high performance low profile street radials available now that actually do a fairly good job... but it is impossible to put all of the torque to the pavement which manifests as tire slip.

What Zeno is saying is of course true at top end also, but very few cars legal for street use can reach their top end speed in 1/4 mile racing.

 

In a 1/4 mile race, the majority of combustion engine muscle cars will find the scale of difference in torque to the wheels for the first 500 feet too much to overcome, which is why the Tesla wins most of the time in these.

The Tesla has hit 100% torque instantly and continued it for that entire time, the combustion engine is rapidly gaining and will likely pass it if given enough time, but a 1/4 mile is insufficient time for most. The Tesla of course to win must be able to put as much of that torque to the pavement as possible the entire time... cold tires will not do that... they will after a few hundred feet because they heat up, but you have lost by then.

 

In the case of all of these cars, they have sufficient HP and Torque to be very fast in spite of tire slip. As is pointed out; that maximum coefficient of friction they can achieve and sustain between the tire and road surface is what determines that maximum acceleration.

Edited by Zathrus~SPARTA~
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I dont think you can warm up the tyres on a 4wd, it burns the clutch. the sound you can hear is the pair in front of them revving up and then pushing off. A Tesla can beat almost everything and certainly most things at its price level.

 

Here's another example to illustrate your point, this time with a hybrid, the BMW I8.

 

 

Again almost nothing can stay with it initially, at first I thought it was reaction time, like the other driver was alseep at the wheel.

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To be fair Tesla added launch control in the December 2015 firmware 7.0 update. This video is from 2014, which probably explains why the Tesla driver overwhelmed his tyres. The GTR has always had launch control (although the clutch was only good for one or two launches in the early versions).

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yes I agree completely Zeno... launch control has to be brutal on equipment.. your really heating that clutch up fast.

 

An extreme example of what I mean, when I was testing the engine/Transmission system for the M1 Abrams long ago...

We had 1500 HP going into dual outputs through an electric shift automatic. This transmission had an enormous

torque converter nearly 3 feet in diameter.

 

If I was running a test and in normal operation the torque converter oil outlet temperature would be sitting between 60 and 80 degrees C.

It is moving 85+ tons so even in normal "road conditions" simulation your generating significant heat. Your oil sump for the transmission holds several gallons of oil and is equipped with coolers.

 

However, if I went to full stall power on the dynamometers (they could stall 60,000 foot pounds of torque each) on each output, and full throttle to the engine, the torque converter outlet oil temperature

would soar from that previous normal range to over 200 degrees C in less than 7 seconds. We used a very special synthetic oil in that thing that

could withstand extreme temperatures for long periods without changing chemically. Even so... we had to change it often... you could tell when it was time because it began giving off a very unpleasant odor when you had worn it out...because of that odor it was often referred to in the lab as "dead dinosaur juice". Because many times these tests took those fluids to temperatures high enough that if enough oxygen could get into the system (it cannot) it would burst violently into flames.

 

The amount & volume of heat generated in a very short time is astonishing. :exclaim:

 

That is an extreme example but I am certain if people could see what their clutches looked like during a drag racing "launch control" start... they would shudder and not do it often.... it is white hot initially for far longer than it should be due to it feathering your launch clutch pressure for maximum tire slip reduction. That is worst case for the clutch to absorb since it is maximum torque loads and your requesting it to slip slightly continuously initially. If I owned the car, I would rather fry the tires than the clutch if it were me. Perhaps they have come up with a launch control that does not do that to a clutch at this point... but even braking the wheels instead does the same thing.. something has to give... which the design point for that give is the clutch. :bike:

Edited by Zathrus~SPARTA~
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