Roadster wins "Race the Runway"

[Doug_G]

I might have missed it but what was the 0-60mph time?

They didn't measure that. They did 1/4 mile time and top speed at 1/2 mile.

 

[djp]

I might have missed it but what was the 0-60mph time?

Negative 0.24 seconds, based on a top speed of 176km/h (and being generous with the 60mph to 109mph acceleration).

In order for the math to work, Doug must have travelled back in time off the start line, emerged from the time warp at 60mph and accelerated up to 109mph over the quarter mile. Now that's an impressive launch!

 

[daniel]

I'd imagine a track has the ability to measure 0-60 time. Have you thought of going back and asking them to do that?

 

[Johan]

This should be submitted to teslamotors.com Roadster sub-site. Way cool! Good press!!!

 

[Doug_G]

Negative 0.24 seconds, based on a top speed of 176km/h (and being generous with the 60mph to 109mph acceleration).

In order for the math to work, Doug must have travelled back in time off the start line, emerged from the time warp at 60mph and accelerated up to 109mph over the quarter mile. Now that's an impressive launch!

You can't do a linear extrapolation. The Roadster's acceleration falls off a cliff above 150 kph. By 170 kph it's down to 12%. At 180 kph it's down to 5%.

 

[djp]

You can't do a linear extrapolation. The Roadster's acceleration falls off a cliff above 150 kph. By 170 kph it's down to 12%. At 180 kph it's down to 5%.

Agreed. The negative 0.24 seconds is an upper bound assuming linear acceleration. I estimate you actually went back in time a full second based on the Roadster's real curve. Very cool. :wink:

 

[joefee]

Way-to-go Doug !

 

[PV4EV]

Assuming the 10.3 was correctly timed, and Doug's car somehow deployed some quantum magic (or possibly a software glitch..) then his 0-60 can be roughly deduced by shifting the Roadster 1.5's curve to the left to match the SS Qtr of 10.3.

From that you can see that the 0-60 might have been 3.2's give or take !!

 

[brianman]

Or you could just watch the 3 different videos from location using editing software (to get finer control over which frames) and try to come up with the actual number.

 

[Tesla 940]

From that you can see that the 0-60 might have been 3.2's give or take !!

I want sub 3.0! :biggrin:

 

[djp]

Doug - sorry, you're right. Linear is a lower bound not an upper bound. I had that backwards.

PV4EV - thanks for the curve. I entered the data into Excel, compressed the time from 12.7sec to 10.39sec and set the distance covered to 0.25 miles. The 0-60 time comes out as 2.05 seconds.

 

[domenick]

Bah! Can't believe I missed this story until now.

That's a truly bizarre 1/4 -mile time. You should consider taking it to a proper track and see if you can nab the SP/A3 (Street Production/349V and above (nominal)) NEDRA record. It currently stands at "only" 12.643.

 

[wiztecy]

I really am boggled about this time. The roadsters only get the 3.7 and 3.9 zero to sixty second times by charging in "Performance Mode" and then doing the clocked runs in "Performance Mode". After a few runs in theory you won't be able to get 3.7/3.9 times. This is what a Tesla Tech told me. Doug, you mentioned you were at 80% SOC and gave rides that would have brought this down even lower. So the realm of a performance charge isn't there in this case. I still don't see how this time was done, I'd like to really hope it got it, but I'm wondering if there can be any error when they calculated the start/stop times.

 

[domenick]

Read back through the thread. I think they key is their timing method at this event. They had some kind of rolling start so a chunk of the normal driver reaction time and normal "hook up" time was not part of their measurement. You wouldn't want to compare these times to something done a "traditional" NHRA/NEDRA type way...

Regardless of the timing method, his performance still seems strangely quick when compared with some of the other cars. I don't think we can compare his time with the official NEDRA record, but it would be interesting to see if there is an anomaly by taking it to the track and giving it a whirl.

 

[donauker]

You wouldn't want to compare these times to something done a "traditional" NHRA/NEDRA type way...

Actually it sounds almost identical to the NHRA/NEDRA events I have run in. When staging for the race you stop when the lights indicate that your front tire has broken the beam a few inches above the surface. On the green you floor it and the timing begins when beam detects the trailing edge of the tire. This equates to around a 1 foot rollout and reaction time is not included. This is standard procedure for timed runs at the multiple official events I have attended.

 

[TEG]

Do you have another explanation how he got a time ~2 seconds quicker than anything reported before?

- - - Updated - - -

From a Google search on "rollout":
How We Test Cars and Trucks

...
A Few Words About Rollout
The term "rollout" might not be familiar, but it comes from the drag strip. The arrangement of the timing beams for drag racing can be confusing, primarily because the 7-inch separation between the "pre-stage" and "stage" beams is not the source of rollout. The pre-stage beam, which has no effect on timing, is only there to help drivers creep up to the starting position. Rollout comes from the 1-foot separation (11.5 inches, actually) between the point where the leading edge of a front tire "rolls in" to the final staging beam — triggering the countdown to the green light that starts the race — and the point where the trailing edge of that tire "rolls out" of that same beam, the triggering event that starts the clock. A driver skilled at "shallow staging" can therefore get almost a free foot of untimed acceleration before the clock officially starts, effectively achieving a rolling-start velocity of 3-5 mph and shaving the 0.3 second it typically takes to cover that distance off his elapsed time (ET) in the process.

We believe the use of rollout for quarter-mile timed runs is appropriate, as this test is designed to represent an optimum drag strip run that a car owner can replicate at a drag strip. In the spirit of consistency, we also follow NHRA practice when calculating quarter-mile trap speed at the end of the run. So we publish the average speed over the final 66 feet of the quarter-mile run, even though our VBOX can tell us the instantaneous speed at the end of the 1,320-foot course, which is usually faster.

On the other hand, the use of rollout with 0-60 times is inappropriate in our view. For one, 0-60-mph acceleration is not a drag-racing convention. More important, it's called ZERO to 60 mph, not 3 or 4 mph to 60 mph, which is what you get when you apply rollout. While it is tempting to use rollout in order to make 0-60 acceleration look more impressive by 0.3 second, thereby hyping both the car's performance and the apparent skill of the test driver, we think it's cheating.

Nevertheless, some car magazines and some automobile manufacturers use rollout anyway — and fail to tell their customers. We've decided against this practice. We publish real 0-60 times instead. But in order to illuminate this issue and ensure we do justice to every car's real performance, we've begun publishing a clearly marked "with rollout" 0-60 time alongside the primary no-rollout 0-60 time so readers can see the effects of this bogus practice...

(Doesn't really answer things, just provides more data...)

- - - Updated - - -

I guess they only just added 1/4 mile timing to what is normally a 1/2 mile top speed radar measurement event?

Quarter mile timing added! | Race the Runway

Posted on August 3, 2012
In addition to two radar guns at the half mile, a timing system will be used to clock times on the first .25. Should make for some interesting stats.

2012 Race Results | Race the Runway

• A timing light system recorded the first quarter mile. The timer started when the first beam was broken by the vehicle
• Some vehicles did not break the quarter mile finish beam for long enough to stop the clock and therefore no quarter mile time was recorded. This happened mostly with the bikes. Sorry guys! We will raise the beam by 12 inches next time so that more of your body breaks the beam. We will need your help in the spring to test this.

Roadster 1/4 times:

#413	Tesla Roadster	10.39
		12.664
		12.651

Notice, of the 3 runs, two were very close, (and seemingly more realistic) 12.6xx times, but then the one outlier 10.39

Sorry to say it, but perhaps a timing clock malfunction?

 

[donauker]

Notice, of the 3 runs, two were very close, (and seemingly more realistic) 12.6xx times, but then the one outlier 10.39

Sorry to say it, but perhaps a timing clock malfunction?

Only plausable explanation based on calculations. As shown in my post upthread you need to nearly double horsepower to the wheels to get that time difference in addition to attaining a trap speed of 131 mph.

 

[djp]

I think timing error is the most logical explanation. Here's a scatter plot of the day's results with top speed graphed against quarter mile time for each car. I've also added a point for the Roadster Sport (200km/h top speed, 12.7 sec quarter mile). The relationship between top speed and quarter mile time looks fairly linear with most cars clustered around the estimate, except for the outlier at 10.39 sec.

The Roadster Sport at 12.7 sec is quite good relative to its top speed, but Doug's time just blows everything else away.