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Hmmm....now if I were to try it with my car... :twisted: LOL, I'd prolly flip :P Though my tires are starting to get a little squeely :P
Is it just me, or there are some types of asphalt that grip alot better than others. It seems that our parking lot(just got repaved) gets really slippery when wet. I have to be a little easy on the gas, or else I just spin :?
Our local suspension guru and autocross champion (nationally ranked - and if I remember correctly, not too far down from the top, either!) did cite the specific example of "the Ford Explorer + Bridgestone/Firestone debacle" from back in the day.Originally Posted by ELVATO
Apparently, even when consumer advocacy groups tried the experiment, they couldn't get the vehicle to flip, and it was later revealed that the original source which made the "easy flip-over" claim actually resorted to modifying the vehicles to INDUCE such a roll event.
In his (our local guru) opinion, yes, roll-overs are more likely in a vehicle with a higher center of gravity/roll - particularly if there's external factors involved - but that it's still rather hard to do, and that normal driving, including "emergency handling," should not cause this behavior.
^ I'm not certain about this, as I'm no traffic engineer.Is it just me, or there are some types of asphalt that grip alot better than others. It seems that our parking lot(just got repaved) gets really slippery when wet. I have to be a little easy on the gas, or else I just spin :?But yes, it does seem that way to me, too.
TSi+WRX, thanks for the update..... that sounds reassuring...
Yesterday, I went out with a few other friends and another car (which happened to be the exact same car as mine just one year younger) and we found a parkign lot at a soccer complex that is used for a boat launch for some near by water and parking at soccer events, being winter no one wass there..... It's also aways from a main street or any businesses or houses (by mabe a good 3/4 a mile to a mile)
The set up was a long rectangulr area with gentle curbs followed by grass and smooth pavement. Also what I found neat was that it came complete with two grassy islands in the center which were perfect to park a vehicle and minimize any chance of accidently hitting that car.
I first tried a 180 degree turn from reverse, since i figured all it required was a sharp wheel turn and a bit of gas. After I got over the intial shock of feeling a wheight shift in my car, I realized it felt quite stable and my favorite predictable. I practiced it a bit more until I could get into a controlled small area ata bout speeds of 15-20 mph.
My next try were handbrake turns/90 degree turns. These were a bit harder, given i have a pedal to operate my e brake, but with a bit of practice I was able to start to hit those pretty well.
The whole time the car felt very stable and I concluded that unless I was powerslding at very high speeds and the wheight was to suddently shift to one side of the car (as in both tires flatten or car strikes a curb) the car would probably not flip.
After we got sick of shredding the sidewalls of the tires (even tho it was a little wet on the pavement) we just sat on the hood of a car, I noticed what appeared to be a security guard or some other personell drive towards us in an explorer. So we left rather quickly trying to make it so he would not be able to see our license plates.
After we went seperate ways onto the main street so he couldnt get us both, I picked up a blip of k band. Then i went down into a valley and it dissapeared and then as i drove on it kept picking up until I it went full blast.. It was a speed sign... I'd say if the limit was 55 we were travelling a bit above it and it took us at least two minutes until we reached it so maybe a good two miles for the initial blip and a mile of a constant alarm (the area was very hilly but straight roads)
I also did a lot more driving later in the day with giving friends rides and donig fun stuff and I looked at my odometer 155 miles in one day. and I burned a lot of gas.
thanks for the responses!
-poker
There was a Car and Driver article on that at the height of the scandal. They bought an Exploder with Firestones (the good old Wilderness ATX) and fitted a device to the wheel that most likely failed (using the statistics of Exploder crashes) that would deflate it very rapidly on demand. They put the car on a track and tried to flip it. Even with the driver swinging the wheels side to side the truck remained on the road... only if he did something REALLY dumb like rapidly jerk the wheel to the side and slam on the brakes or something like that...Our local suspension guru and autocross champion (nationally ranked - and if I remember correctly, not too far down from the top, either!) did cite the specific example of "the Ford Explorer + Bridgestone/Firestone debacle" from back in the day.
Apparently, even when consumer advocacy groups tried the experiment, they couldn't get the vehicle to flip, and it was later revealed that the original source which made the "easy flip-over" claim actually resorted to modifying the vehicles to INDUCE such a roll event.
In his (our local guru) opinion, yes, roll-overs are more likely in a vehicle with a higher center of gravity/roll - particularly if there's external factors involved - but that it's still rather hard to do, and that normal driving, including "emergency handling," should not cause this behavior.
^ I'm not certain about this, as I'm no traffic engineer.Is it just me, or there are some types of asphalt that grip alot better than others. It seems that our parking lot(just got repaved) gets really slippery when wet. I have to be a little easy on the gas, or else I just spin :?
CG is very important in terms of flipping. Basically, the ONLY way for you to flip a car, is for you to get the centre of gravity to lie somewhere outside of the vehicle's track. Ie if the CG is left of the left wheels, or right of the right, the car flips. Otherwise the car does not flip. Of course if the road is banked then the angles change with velocity since the acceleration of the car is pushing against but I digress :P As the CG is made higher, it becomes easier to put the CG outside of the track, if the track isn't widened enough to compensate (heh, a 3 lane SUV).
Different surfaces do act differently. For example concrete doesn't grip as well as asphalt, and if you had really smooth (ie not as porous) asphalt with poor drainage it would be slippery when wet.
^ Ah, my Saab-loving friend, that was going to be my initial response, too....but I think that our friend ELVATO had honed-in on the way that different patches of what looks to be the same type of "asphalt" can also feel different, traction-wise.
While I certainly do agree with you on what you posted above, I also can definitely feel differences in what should have otherwise been two similar patches of asphalt or concrete - and what I don't know is if either their surface preparation, or even the "type" of roadway material itself (i.e. one specific "type" of concrete vs. another), if there's any such thing - is what's causing this difference in feel.....
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poker192 - Good to hear that you guys were able to experiment safely!
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