0-60 teaser

[cosnww]

Ok, say you have two cars identical 0-60 times and you both race from the lights. Ignore things like traction, gear change etc ....

When both cars hit 60, will they be side by side ?

I think interestingly enough they wont necessserily (spelling ?!) be.

I think it may be due to the fact that acceleration is not constant and different gear ratio's etc ....

- But what do you think ?

[Marky Boy]

Yeah they'd travel the same distance.

accleration = change in velocity / time.

so if they both take the same change in total velocity 0 - 60 mph in 6 seconds acceleration = 10mph/s

Displacement = (initial velocity x time) + 1/2 acceleration x time squared.

displacement = (0x6) + (5 x0.0408hrs)
= 0.204 miles

So theyd both reach 60 after .204 miles I think.
:)

[tim rome]

everything would have to be exactly the same, ie. drivers weights, both exactly the same amount of fuel from the same filling station filled up at the same time. same tyres with exactly the same amount of tread it goes on and on

[Dave_S]

Put a mini and a bigfoot next to each other (if they had the same 0-60) and see which one's furthest away ;)

Dave

[Martin T]

The car with that is fastest initially will be further away.
Imagine this:
2 cars 7 sec 0-60
car 1 does 0-50 in 0.1 of a second, then takes nearly 7 secs to do 50-60
car 2 does 0-10 in 6.9 secs, then takes 0.1 secs to go from 10-60

car 1 will be miles ahead as its been going faster pretty much the whole time.

[cosnww]

some good points, especially on pull away - since you will have the edge from then on.

Marky Boy, your acceleration equation is correct for linear acceleration - but we dont have uniform accel, otherwise i would agree.

Imagine you have a graph of SPEED against time. Now plot speed vs time for two different types of engine in a car that reaches 0-60 in the same time.

Engine 1 is a race tuned version which has a narrow power band up in the high rpm range.

Engine 2 is a big torquey engine.

For ease imagine, you can do 60 in 1st !!! (ie: eliminates gear change for simplicity)

Now engine 1 will produce a speed increase slowly with a sharp upward peak towards reaching 60.

Engine 2 will produce a relative high speed increase initially falling off towards 60.

Since distance travelled is proportional to the area under the curve. Engine 2 has the most area - hence the most distance travelled.

Hence distance travelled is dependant on the shape of the power delivery curve.


I hear you ask - so what ?

Well when we are all comparing performance figures between cars, surely on the road - its who is in front that counts ?

For example a corrodo G60 has a fairly poor 0-60, its about 8.7 but how can that be on a supercharged 1.8. But maybe on a strip it would be cars ahead of other vechicles that claim 8.7 to 60.

[mickstreet]

Cosnww,

Yes you are right, distance travelled is area under the time/speed graph. If you knew this then why ask the question though?:confused:

[Chris_Lacey]

Confusing one this :)

I think a classic example would be at the last TSC. I had a terminal speed on the quarter of 95 I think on one of my runs, there was a scooby with a terminal of 88 and the same time...

So I got to 90 a fair way ahead of the Scooby, which probably got to 60 before me.. lol

I hate these kinds of problems :)

[cosnww]

mickstreet,

when i posted the question - I did not know the answer, then after reading the replies and thinking about it some more - the answer became apparent.

Chris, yep - thats just the sort of thing that makes you think well which figures mean anything !
Also I think scoobs have such a quick 0-60 since they can get to 60 in 2nd wheras we have to grab 3rd in a 200 to get to 60.

Cheers for inputs guys,
Nick.

[mickstreet]

Originally posted by cosnww
mickstreet,

when i posted the question - I did not know the answer, then after reading the replies and thinking about it some more - the answer became apparent.

Chris, yep - thats just the sort of thing that makes you think well which figures mean anything !
Also I think scoobs have such a quick 0-60 since they can get to 60 in 2nd wheras we have to grab 3rd in a 200 to get to 60.

Cheers for inputs guys,
Nick.


3rd to get to 60? which car you got? I get get over 70 in 2nd, it is pushing it but not into the redline.:confused:

[mike_s14]

Originally posted by mickstreet
3rd to get to 60? which car you got? I get get over 70 in 2nd, it is pushing it but not into the redline.:confused:

hit the limiter in mine at trax last year

nearly 80 in second :eek: :D

[Pauly_Boy]

I take it that the S14 has longer gearing then :)

I think 60 in 2nd would be about 6,500 - 7000 rpm in my S13.... maybe i should get bigger wheels

[Chris_Lacey]

Get an S14 Diff, job done :)

[Ripper]

If you had two cars with identical 0-60 times but one was RWD and one was FWD then Newton's 12th law would come into force:-

And I quote "FWD is shite so the published acceleration times will be based on the one day they managed to get the wheels to grip and is therefore totally unrealistic. Add at least two seconds. And about 4 if it's raining".

The RWD car would accelerate as per published performance figures.

:)