In my area there are country roads that have a speed limit as high as 55 mph. However, a T intersection would usually have a stop sign. If not, one would want to make very sure there was no traffic. Perhaps if one were making a right turn from the top left of the "T" down the stem, the only traffic of concern would be left turners coming from the top right of the "T" and could be plainly seen.

Would the radius of such a right turn really be around 60 ft? That seems like a rather large radius for such a sharp turn.

 

Several of the country roads where I live have an L turn. Usually to go around farm land or some other obstacle. Very little turn radius on these, I would guess 45-60 feet. On these sorts of roads, the ongoing traffic is not a as big of a problem as it would be at a T intersection, unless of course you slide into the other lane (then you may have a big problem). It seems that a Mini S with limited slip and sports suspension is usually capable of performing a turn at least 15 miles over the posted speed (although I would never ever think about doing such a terrible thing). Having been a truck driver in a former life, usually these posted speeds on curves are calculated based upon a much larger vehicle with a much higher center of gravity, such as a delivery truck. Now, my question is, how many drivers spending money on a Mini can actually say they never exceed the posted speed limit? Certainly, in residential area, this would be bad news, but out in the middle of now where, I've got to believe that most of us have, once in a while, given into temptation.

 

Legal council advises me not to comment.

 

But what number is correct. See http://www.roadandtrack.com/assets/d...anel-fixed.pdf
R&T MCS JCW 200' skidpad, .83g

See http://images.motortrend.com/feature...ng+skidpad.jpg
MT MCS GP, no mention of how big the skidpag may be ... .82g (pretty bad in that company of cars).

Magazine testers will usually tell you and use the exact some radius for skidpad tests. Does the grip change with smaller or bigger radius? 45 - 50 feet is a far cry from 200' so I'm not sure that .91g is meaningful.

 

In theory, skidpad results are independent of the radius of the skidpad, because of the physics behind the calculations. In reality, the larger the skidpad, the lower the result will be, because of the loading on the car's suspension as the speeds increase. However, unless you're testing a heavy car with an extremely high center of gravity and extremely soft shocks, the real-world differences between skidpads of varying radii is actually pretty small.

And going back to my equation, the maximum cornering speed only depends on the square root of the skidpad rating, so even going from .91g to .83g doesn't change the final result much. At .91g, the max speed was 28.6MPH, and at .83g, it's 27.3MPH.

So, the final estimate (and that's all it is - an estimate) is still in the ballpark, regardless of whether you use .91g or .83g.

There are other variables, such as road/tire composition, that have to be factored in, but since he has stock tires and is talking about dry road, the differences aren't going to cause the final estimate to vary wildly.

Also, I should say that even though I'm giving the estimates to three significant figures (28.6MPH, 27.3MPH), I'm only doing that in case anyone else wants to follow along with the math. In reality, that level of precision isn't justified, so I would normally round both of those results up to 30MPH.

 

thanks