What Do You Think Of This?

[XtcGinga]

[Woody27]

Not convinced tbh. You could easily create that difference in time between just two different starts with less wheel spin and quicker gear changing/less slipping of clutch! Also if the car had less petrol in would weigh less etc and virtually impossible to get exact same amount of petrol in!

Plus, and correct me if i'm wrong, i was always under the impression that you're better off changing gear at about 5,500rpm when driving hard as the power tails off before the redline. Therefore you could get better acceleration just by improving the way it's driven!

[Al J]

Hmmm....

150k, what's that, about 93mph?

Well we can knock about 10% off that for a start for speedo error so about 135km/h (around 83mph).

Then there's the timing. Average reaction time 0.1 - 0.2 second. There's the start and stop timing so the errors either cancel themselves out or compound to give up to 0.4s timing error. That's about the same as the "improvement" from 0-50km/h in this case.

Oh and I thought the increase in octane wouldn't make any/much difference in a small engine like this.

In other words... pointless and unscientific. If it had been done on a dyno then that would have been a different matter altogether.

Added to that it looks like this was done on one run. An average of 5, 7, 9 or even more results would have given a more plausible time as it divides your timing errors.

Bad maths. Bad Science. Dubious result.

Al (a physicist)

[XtcGinga]

Thanks for the replies!

Off course this is everything but scientific, but it works for me to have some record about the changes in the car. I tried to make things as equal as possible, same place, same people in the car, same petrol... Too bag I don't have access to the correct ways to do it. ;)

Thanks ;)

[Madasafish]

Have to agree with Al. (I'm a physicist as well.. :-)

I can think of one very good reason why the ORDER in which tests are completed affect results.

Consider car from cold. Only driven 10 miles so water temperature = warm but engine and gearbox oil = cold.

One test drive gives timing 1.

Now engine and gearbox oil warmed up (also tyres) .. so less internal friction and ...better accleration.

Hey presto: 1 or 2 dseconds less.

Imo the test would only be meaninful on the same road strip and with 10 timed runs all back to back withe the same driver and same fuel weight at start...Take an average.. and you would find that:

driver error/or otherwise would impact results more than any other factor...