minumum acceptable acceleration in a general use automobile.
minumum acceptable acceleration in a general use automobile.
(OP)
Are there any guidelines as to the minumums for acceleration? here inthe US I would assume minumum sustainable speed would have to be 75 mph (120kmh).So in the quest for smaller motors for higher fuel mileage is there a limit as to how slow a car you can make?





RE: minumum acceptable acceleration in a general use automobile.
I get about 13 m/s2
TTFN
RE: minumum acceptable acceleration in a general use automobile.
Dan - Owner
http://www.Hi-TecDesigns.com
RE: minumum acceptable acceleration in a general use automobile.
Or the thousands of on ramps that are nice and long but have a red light at the freeway end. 1/4 mile in 25 seconds?
RE: minumum acceptable acceleration in a general use automobile.
In Florida, there are lots of slow cars. But, this is a limitation of the driver, not the vehicle!
RE: minumum acceptable acceleration in a general use automobile.
My Mini had 40 hp and was capable of keeping up with London traffic (and if you don't know what that means, fine, but don't be a smart-a).
You'd probably find that gradient climbing at speed is what really sets the power requirement.
I have seen data logged for cars for millions of seconds, it is very interesting to plot rpm vs throttle opening to see what performance real people actually use.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: minumum acceptable acceleration in a general use automobile.
Obviously, not many cars actually get up to the minimum safe speed at the onramp. I've drive it once, and it was a harrowing experience, because there's no way to see if there is any oncoming traffic coming up from behind until they get around the bend in the freeway, which is only about 100 ft back of the onramp.
The Pasadena freeway was built back when cars didn't go much more than 40 mph to begin with, so apparently, the designers felt comfortable with the onramp design back then.
The 0-60 mph time for a Porsche 911 can get down to 3.4 seconds, which is only 7.9 m/s2(http://a
A more pedestrian time would be in the 10-20 second range, so the long side would be about 0.1 g
TTFN
RE: minumum acceptable acceleration in a general use automobile.
http://www.eurotuned.com/0-60.htm
There are several cars, albeit quite old, that take about 20 seconds to do 0-60, so that's about that, other than the faster guys flipping you off for driving so slow as they pass you.
TTFN
RE: minumum acceptable acceleration in a general use automobile.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: minumum acceptable acceleration in a general use automobile.
50hp in a Fiat Panda is about the same as over 200hp in a lot of SUVs.
Bill
RE: minumum acceptable acceleration in a general use automobile.
As for the lower limit on acceleration potential, that's a function of whatever minimum value will find sufficiently wide consumer acceptance. Reducing it below some vague point would probably involve psychological stuff and lots of consumer education - I suspect that most people don't care to use wide open throttle very often and would really hate to feel that they had to on a regular basis. And end up hating the car for it.
Greg has previously mentioned the ability to maintain speed on grades, to which I'll add coping with headwinds if a low maximum speed limited by power is selected.
Keep in mind for minimum top speed purposes (presumed reasonably achievable if set barely above normal posted speed limits) that the last few mph is added very slowly, as there is not much surplus torque available to accomplish the acceleration. The last mph could take over half a mile to add.
I'll have to bounce this topic off someone I know who drives an 18-wheel flatbed for a living (OTR) the next time he's in town, just to get thoughts from a different point of view.
Norm
RE: minumum acceptable acceleration in a general use automobile.
Me in a Panda adds about 12% to the weight. Me in a humongous SUV isn't worth working out.
RE: minumum acceptable acceleration in a general use automobile.
RE: minumum acceptable acceleration in a general use automobile.
But then again I'm not your average driver....
(And I dont drive your average econobox... yet.)
Nick
I love materials science!
RE: minumum acceptable acceleration in a general use automobile.
Dan - Owner
http://www.Hi-TecDesigns.com
RE: minumum acceptable acceleration in a general use automobile.
If there is not a minimum there should be. lol
I don't know anything but the people that do.
RE: minumum acceptable acceleration in a general use automobile.
TTFN
RE: minumum acceptable acceleration in a general use automobile.
RE: minumum acceptable acceleration in a general use automobile.
To some extent, the above are in conflict with each other. But if it can be assumed that people really won't hold the accelerator pedal flat to the floor for miles on end maybe there's a loosely defined range of top speed that satisfies the other criteria.
Norm
RE: minumum acceptable acceleration in a general use automobile.
But the simple answer is that you can divorce the acceleration from the speed by using a governor. An electronic one could even allow you some leeway with a limited duration of higher speeds for passing.
TTFN
RE: minumum acceptable acceleration in a general use automobile.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.