Cal Club Autocross Forums

I get it, there is not a reliable way to convert 0-60 ft to 0-60 mph but is there a formula that can help me speculate how much my 0-60mph times would be?

I was looking at here:
http://216.58.239.33/SSM.html" onclick="window.open(this.href);return false;
and more specifically here:
http://216.58.239.33/timeslip/55SSM.html" onclick="window.open(this.href);return false;

and I saw that in one of the times I did:
TIME 45.236
RT 0.521
60ft 2.227
(This was on the cold Saturday evening... no chance to run on Sunday)

Since I have no perception of what that means I wanted to estimate what 0-60 mph time might be...

Thanks,
Chris

I guess 0-60 ft is super short to give an indication of anything significant... as an example the monstrous SSM RX-7 and the civics were having similar 0-60 ft time but I'm willing to bet that the results would be significantly different for the 0-60 mph and 1/4 times when the wheel spin won't be a big issue .

Chris, here is a page that has almost every calculation except the one you want.

http://www.wallaceracing.com/Calculators.htm" onclick="window.open(this.href);return false;

Don

Christos Adam wrote:I get it, there is not a reliable way to convert 0-60 ft to 0-60 mph but is there a formula that can help me speculate how much my 0-60mph times would be?

I was looking at here:
http://216.58.239.33/SSM.html" onclick="window.open(this.href);return false;
and more specifically here:
http://216.58.239.33/timeslip/55SSM.html" onclick="window.open(this.href);return false;

and I saw that in one of the times I did:
TIME 45.236
RT 0.521
60ft 2.227
(This was on the cold Saturday evening... no chance to run on Sunday)

Since I have no perception of what that means I wanted to estimate what 0-60 mph time might be...






Thanks,
Chris

I can't see how that calculation would be possible Chris. Too many variables.

If you assume that you can continue to accelerate at the same rate all the way to 60 mph (which is true for very powerful cars that are traction-limited), then there is a simple solution.
Let s1 = 60 ft = 18.3 m
t1 = 2.227 s (your elapsed time to travel 60 ft)
a - the acceleration (assumed to be const)

v2 = 60 mph = 96.54 km/h = 26.8 m/s
t2 - the time in s to reach 60 mph

From high school:
s1 = 1/2 *a*t1^2
v2 = a*t2

Solving for t2:
t2 = 1/2 * v2 * t1^2 / s1 = 3.63 s

This is the lowest limit. Given a 0-60 ft time, you won't be able to reach 60 mph in less time than that. If you didn't have to shift in the first 60 ft, but you expect a gearshift on your way to 60 mph, then you must add the time for the gearshift - at least 0.3 s for a 3-pedal manual transmission.

Mihail Milkov wrote:If you assume that you can continue to accelerate at the same rate all the way to 60 mph (which is true for very powerful cars that are traction-limited), then there is a simple solution.
Let s1 = 60 ft = 18.3 m
t1 = 2.227 s (your elapsed time to travel 60 ft)
a - the acceleration (assumed to be const)

v2 = 60 mph = 96.54 km/h = 26.8 m/s
t2 - the time in s to reach 60 mph

From high school:
s1 = 1/2 *a*t1^2
v2 = a*t2

Solving for t2:
t2 = 1/2 * v2 * t1^2 / s1 = 3.63 s

This is the lowest limit. Given a 0-60 ft time, you won't be able to reach 60 mph in less time than that. If you didn't have to shift in the first 60 ft, but you expect a gearshift on your way to 60 mph, then you must add the time for the gearshift - at least 0.3 s for a 3-pedal manual transmission.

you'd be way closer assuming 2 levels of constant acceleration, 1st gear and 2nd gear, with the eqn's split at your shift point speed. you can take a pretty good guess at your accel values for each gear if you know your torque curve and overall gearing.

Wouldn't it just be easier to get a stopwatch and accelerate to 60?

Kurt Ra wrote:Wouldn't it just be easier to get a stopwatch and accelerate to 60?

hey you watch your mouth! it's not about being easier, it's about wasting time at work!

the evo averages .9g's in 1st gear and .45g in second, with measured 60' times of ~1.7sec and 0-60 times ~3.9sec

Marshall Grice wrote:

Kurt Ra wrote:Wouldn't it just be easier to get a stopwatch and accelerate to 60?

hey you watch your mouth! it's not about being easier, it's about wasting time at work!

Sorry...forgot I was talking to an engineer