Hats off the organizers for a top notch event!!!

As per the discussions with the event organizers this was their first event and there may be some flaws. I want to discuss something that did not sit well with me during the braking event. I want to discuss this so as to improve the test in the future and not to discredit the results.

The brake tests were conducted on the 1/4 mile track by accelerating to 100 MPH then slaming on the brakes and the GPS system measured the results in feet.

First question is since each car reached the 100MPH mark at different points on the track there was no consistincy as to the surface area from car to car. The difference between where each car stopped was very dramatic and the tracks surface rubber content varied toward the end.

Second question is that when the car is accellerating thru the 100MPH mark the cars momentum continues to push the car forward harder than what it would be if the car were crusing at 100MPH then applying the brakes. Simple physics would prove that the harder the car accerated (rate of accelaration) the greater the difference would be. This may also be why the Fred's cars did so well when compaired to the others.

Third question is how difficult is it to accelerate to exactly 100MPH then apply the brakes at 101MPH. The GPS measurement starts at exactly 100MPH.

I propose for future events that the cars reach a crusing speed of 100MPH and start braking at the same point on the track as to help keep the results more accurate. I believe this is how Car & Driver and OEMS conduct the tests.

 

If the test was only to measure 100-0 time and distance then reaching cruising speed first would make sense as you said. However, if the test was to see who can do the 0-100-0 roundtrip fastest then reaching cruising attitude first would not make sense. Yes, it takes a very skillful driver to be able to brake at 100 on the nose. Maybe setting an alarm (with the speed limiter) that sounds when 100 is reached will make it easier.

 

Did you ask the Drivers how they did it? Maybe that is the first thing to do as I am curious now that you mention it. Although I did notice that 2 of the quickest cars had some of the best braking. Not to knock your theory.

 

k24, I agree. Doing this scientifically and accurately is somewhat difficult. Without controlling many variables, as you point out, the results I bet are worthless. Did they do replications to test for process noise? No way I bet. The results are worthless as I stated in another thread.

 

They did repeat the test 4 times. Each driver had one warm up stop per car then one stop test and then changed sides of the track to test again. The process was repeated again with the other driver. I am impressed that they did this to try to make the test as accurate as possible.

The rate of acceleration difference per car combined with the weight of the car will skew the results.

As I said when I started this thread this was NOT intended to discredit the results but to help refine future tests. I am just looking to see who agrees with me so when can pass it on to the power at be for the next event. This was a first class effort and I am sure they will be looking for input in future events.

Now this also gives you armchair quarterbacks time to prep your cars and join us next year!

 

Something else to ponder. Assume each car accelerated full throttle to 100MPH and the lifted the gas and pushed in the clutch (sorry sharkey). Do you think the top speed each car would reach would be the same?

Hell no! Rate of acceration and weight would determin the momentum at which the cars would continue on to reach peak MPH.

 

In that case, they should capture the 0-100 times and the 100-0 times in a bar graph. Other car mags do that to let the reader know rate of acceleration and stopping power.

Sure the weight of the car can skew the results but since there is no weight penalty or the size of brakes it's really fair game.

 

We all know that weight savings is an advantage in braking. The problem is that the momentum from the 0-100 acceration varies due to weight.

 

Do they step on the clutch when they brake at the same time?

 

Not sure if they do.

 

I assume they're in 3rd when they hit 100?

 

They should have done the testing with the Stalker ATS (STATS) radar gun, that gun is what most magazines use to conduct the test.

Stalker ATS Link

 

The proper way to do this is to attach a 5th ( which is calibrated properly) wheel to the vehicle , it will measure acceleration and deceleration properly.
All cars will be different and you must factor in speedo error if it is done any other way.,