The answer:
Don't time the speedometer, time the tachometer.
Start the stopwatch after you dump the clutch and stop the clock at 8100RPM (2nd gear).

8100RPM (2nd gear) = 60mph;I verified it by driving 60mph constant for a period of time and record the rpm.

I have also learnt that our digital speedometer "samples and holds" reading for a "period of time". I suppose this is done so that the speedometer is not flicking number at a fast rate (poor readability and not pleasing to eye). That is why during hard acceleration, we see numbers that jump 30, 37, 45, 52, 58, 64, etc...
Therefore, it is very difficult to accurately know when the 60mph is by looking at the speedometer during hard acceleration.

In the past, I have been timing it by watching the speedometer and did not realized that I was always LATE since I waited for the speedometer to show 6x MPH when it typically jumped from like 58 -> 65.(many times the speedometer never displayed 60, it jumped from like 56 to 63 or 58 ->65). I was getting 7.1s average.

By timing the RPM, I am now getting 5.5s which is in line with G-tech number.




[Edited by asin on 03-07-2001 at 06:12 PM]

 

asin,

Not a bad idea bud. I think I got close to 7.5 using the spedometer one time!

 

Timing by stopwatch is flawed, at best. Your reaction time at the beginning and end skews the results. G-Tech is probably your best bet for accurate timing.

 

I accept your comments about the speedo ASIN but I think you'll find 60mph = 8,400 - 8,500 revs. In any case it isn't really relevant - you will not get close to anywhere near a reasonable degree of accuracy with a stop watch for 0-60.

Leave the stopwatch for your track lap times.

 

2kturkey,

If you try to stay constant at 60mph in 2nd gear for 5 seconds or longer, you will notice that the RPM is at 8100-8200.
Road&Track and C&D also show that the 2nd gear ratio is 7.3MPH/1000RPM -> 60MPH@8200RPM.

 

Asin, I did the sums again and I now work it out at 8,310 (assuming 9k revs = 65mph) so I'm happy to call it splits.

 

Deal.

I know timing 0-60 with stopwatch is not the most accurate.
However, I have been able to time all my cars and gotten results that are within +/- 0.2 seconds of C&D or R&T test results. All my other cars have analog/needle speedometer, so it has been very easy to time the needle hit "60" mark and stop the watch.

I was frustrated with my 7.1s average number when I try to time S2K by watching the speedmeter as the number moves in unpredictable increments during hard acceleration. I was wondering why my 0-60 sucks.
Now that I time the 0-60 by RPM @8200, I have been getting 5.5 -> 5.9 range which is consistent with other mag review.
I just want to share my discovery and excitement to know you can prove that your car is capable of 0-60 under six seconds.

 

S2000 does 105km/h (65.625m/h) in 2nd gear. That means to do 60m/h (96.5km/h) you need to be pulling 8,271 revs. More or less what 2kturkey worked out. If this does not match the speeedo then the speedo is wrong.

Also, the stopwatch intorduces up to 1 sec in error and makes the 0-60m/h times very innacurate.

ps. For us 'metric' guys - in order to do 100km/h (62.5m/h), you need to be doing 8.571 revs (ie. 8.6k).