View Full Version : Rolling over in Autox possible?
I know I worry for no reason, particularly being an engineer and all, but just how feasible is a rollover on an E46 sedan while autoxing?
I assume it is impossible because the tires cannot hold enough grip to allow the car to pivot about them hence allowing it to roll over. They would brake loose before this and the car would just spin.
I guess I am a bit nervous about doing something stupid tomorrow since it will be my first time pushing the car hard on dry weather. Both my 1st autox and my driver's school were in the rain. I wonder what if turn the wheel too much too quickly in dry weather. I will be running older Contis on M68's.
I want to hear some input form guys who know if anything just for fun.
(Hey, it's my 1st thread at the revolution!) :cool:
I know I worry for no reason, particularly being an engineer and all, but just how feasible is a rollover on an E46 sedan while autoxing?
I assume it is impossible because the tires cannot hold enough grip to allow the car to pivot about them hence allowing it to roll over. They would brake loose before this and the car would just spin.
I guess I am a bit nervous about doing something stupid tomorrow since it will be my first time pushing the car hard on dry weather. Both my 1st autox and my driver's school were in the rain. I wonder what if turn the wheel too much too quickly in dry weather. I will be running older Contis on M68's.
I want to hear some input form guys who know if anything just for fun.
(Hey, it's my 1st thread at the revolution!) :cool:
Anything is possible.
Do I think there is even a remote likelihood? No.
Anything is possible :twisted: (however very unlikely)
There was a post on the 'fest with an E30 waaay up on 2 wheels, if I recall correctly it did not roll...
edit: just to clarify, TD posted while I was typing my response. Very similar responses though huh...
SpaceMonk
10-17-2003, 03:48 PM
You may spin, and do a 180 or 360, etc. I've done that. But it's damn near improbable that you will never spin your car on our autocross courses. I don't know what you want to hear, because TD is right, isn't not impossible. But I would bet all the money I had that it wouldn't happen.
You probably would have had a better chance rolling your car at the ADSS last weekend if you were pushing the speeds on the lane change exercise.
Just be sure to turn off DSC entirely for all your runs this time. :thumbup:
Nick M3
10-17-2003, 03:48 PM
Someone hit a curb sideways at a high enough speed to total the car... No roll over.
Don't worry, you'll probably understeer a lot, and maybe spin. No rollover. :)
clyde
10-17-2003, 03:50 PM
I hate to break it to you, but it's not impossible. To put into context, is it possible that you will get into a horrific car crash on the way to/from the event tomorrow? Yes. Which is more likely to occur? The horrific car crash...probably by far.
Well that's what figured. I am sure if I deliberatelly yank the wheel as hard as I can at 50mph the car WILL roll over, but assuming somewhat gradual turns even with abrupt power, I figure a rollover wont happen.
:lol:
never heard of that happening at auto-x... (but i don't auto-x...)
like what TD said, anything could happen, but u have to be really stupid to roll over at an auto-x, and it would be extremely embarrasing...
--Andrew
clyde
10-17-2003, 04:14 PM
Well that's what figured. I am sure if I deliberatelly yank the wheel as hard as I can at 50mph the car WILL roll over, but assuming somewhat gradual turns even with abrupt power, I figure a rollover wont happen.
No, not really (to the former).
Yanking the wheel as hard/fast as you can at 50 mph will move the front tires beyond their optimum slip angles and consequently the outer tires will never have the opportunity to start generating the force required to roll the car.
A rollover will be much more likely in a transition area going from substantial lateral force in one direction to substantial lateral force in the opposite direction in a very fast, smooth motion.
clyde
10-17-2003, 04:17 PM
:lol:
never heard of that happening at auto-x... (but i don't auto-x...)
like what TD said, anything could happen, but u have to be really stupid to roll over at an auto-x, and it would be extremely embarrasing...
--Andrew
It does happen. You don't have to be stupid for it to happen though. In fact, you generally need to be a pretty damn good driver and/or driving a car with setup issues.
Or you could hit something and/or the pavement be just so (in terms of depressions, ridges, surface quality, etc) and/or get caught by a sudden gust or calming of wind and/or have a mechanical failure and/or etc.
Well that's what figured. I am sure if I deliberatelly yank the wheel as hard as I can at 50mph the car WILL roll over, but assuming somewhat gradual turns even with abrupt power, I figure a rollover wont happen.
No, not really (to the former).
Yanking the wheel as hard/fast as you can at 50 mph will move the front tires beyond their optimum slip angles and consequently the outer tires will never have the opportunity to start generating the force required to roll the car.
A rollover will be much more likely in a transition area going from substantial lateral force in one direction to substantial lateral force in the opposite direction in a very fast, smooth motion.
You are right. The car would just plow. I overlooked that. Not thinking straight today after Grady Little lost the game for us. I am actually quite depressed, but that's another story.
dredmo
10-17-2003, 06:32 PM
FWIW, and I don't know how this exactly applies, but with both the DSC on and off, I have never once been in a situation that could even remotely present the possibility of sliding, and I take my car out at least once a month on some twisties that some of you city boys would die for... :twisted:
Anyways, I think you should be safe, TD is right, it is possible, but so unlikely.
The most probable cause of flipping is when someone slides on ice at a high speed and they hit dry pavement and it catches and starts to roll the tire instead of sliding it, and you would almost need to catch both tires to do this.
Since your will be leading with front tires, driving with your back, and never full on breaking, I see no possible way you could flip.
Debris in the track is bad though, watch out for that.
ACS_B_323Ci
10-17-2003, 11:19 PM
it could happen but it would be some kind of a fluke... and most likely a result of you losing control and hitting a large curb/object while moving sideways...
drive safe and fast... and remember to have lots of fun!!!
Nick M3
10-17-2003, 11:23 PM
it could happen but it would be some kind of a fluke... and most likely a result of you losing control and hitting a large curb/object while moving sideways...
drive safe and fast... and remember to have lots of fun!!!
And even then, the odds of rolling the car are still pretty poor.
In spite of my best efforts, I have STILL not managed to get a wheel into the air. ;)
SpaceMonk
10-17-2003, 11:23 PM
it could happen but it would be some kind of a fluke... and most likely a result of you losing control and hitting a large curb/object while moving sideways...
drive safe and fast... and remember to have lots of fun!!!
No curbs or objects to hit on an old abandoned military airfield. :D
Well, as long as you don't consider State Trooper cruisers objects.
In spite of my best efforts, I have STILL not managed to get a wheel into the air. ;)
I can attest to Nick's efforts...he may have been unsuccessful but I have seen an X5 lift a tire and it didn't slow him down one bit :P
It happens every once in a while, typically on cars with very soft suspensions and large anti-roll bars.
Do I think it is possible in an E46? no.
It does happen. You don't have to be stupid for it to happen though. In fact, you generally need to be a pretty damn good driver and/or driving a car with setup issues.
Or you could hit something and/or the pavement be just so (in terms of depressions, ridges, surface quality, etc) and/or get caught by a sudden gust or calming of wind and/or have a mechanical failure and/or etc.
Cool, I didn't know that... Learned something new! I might try out auto-x'ing some day, as the place is only 5 minutes from where I live. But with my tire setup, I can't be in the stock class and will probably get my butt kicked... :(
--Andrew
clyde
10-20-2003, 08:31 AM
Cool, I didn't know that... Learned something new! I might try out auto-x'ing some day, as the place is only 5 minutes from where I live. But with my tire setup, I can't be in the stock class and will probably get my butt kicked... :(
So? No matter what tires you have and no matter what class you run in, you will probably get your butt kicked the first few times out anyway. Experience counts for more than anything else..
Well, I went Autoxing last saturday and it was a blast. My first experience in dry weather. It was lots of fun. I was surprised how easily I could get the tail to swing around. Tires (Contis) squealed a lot. As far as rolling over, as I figured the tires lost grip way too early for that to happen, and since the weight of the car was not shifted THAT quickly there was no chance for a rollover.
I got to see the best Autoxer go nuts with his (very) modified '98 M3/4 running on R-compounds and his amount of grip was just ridiculous. Around this one right turn (I was working the cones there), his front-right tire consistently left the ground by about 2". Crazy stuff.
Oh yeah, I LOVE my car. :D
Scott_H
10-20-2003, 10:41 AM
Went with my Son to the Street Survival School this Saturday. There was a young lady there running her All Trac Chevy Astro Van, and running it hard! She was great to watch, but a couple of us were cringing when she ran wide of the wet patch on the skid pad. Not a ton of effort would be required to roll that baby on dry pavement.
Scott
Well, I went Autoxing last saturday and it was a blast. My first experience in dry weather. It was lots of fun. I was surprised how easily I could get the tail to swing around. Tires (Contis) squealed a lot. As far as rolling over, as I figured the tires lost grip way too early for that to happen, and since the weight of the car was not shifted THAT quickly there was no chance for a rollover.
I got to see the best Autoxer go nuts with his (very) modified '98 M3/4 running on R-compounds and his amount of grip was just ridiculous. Around this one right turn (I was working the cones there), his front-right tire consistently left the ground by about 2". Crazy stuff.
Oh yeah, I LOVE my car. :D
My first driving school was at Gratten in Michigan - a very small, tight track designed by somebody who understood everything there is to know about high speed driving that hated drivers. The modified e36 m3's with tight suspension setups lifted a wheel on several corners every lap (both sides). It was fairly interesting to see, but I suspect the suspension settings aren't optimal if you are giving up the entire traction of one tire consistently.
clyde
10-21-2003, 02:03 PM
The modified e36 m3's with tight suspension setups lifted a wheel on several corners every lap (both sides). It was fairly interesting to see, but I suspect the suspension settings aren't optimal if you are giving up the entire traction of one tire consistently.
Generally, lifting the inside front of a RWD car on corner exit under power means that there's too much roll stiffness up front. Briefly lifting an inch or two isn't that big of a deal if the roll stiffness is improving turn in or other characteristics. The outside front tire is doing damn near all of the work anyway.
What's fun to watch are the SWB FWD cars that lift the inside rear a foot or so. :thumbup: :D
What's scary is watching RWD cars lift the inside rear. There's a guy locally who has been doing that a lot in his 1973 CS 3.0 this year. Unfortunately, I heard that he burned a piston recently.
Roadstergal
11-02-2003, 03:23 PM
So? No matter what tires you have and no matter what class you run in, you will probably get your butt kicked the first few times out anyway. Experience counts for more than anything else..
I get my ass handed to me all of the time. It's still fun, and I'm a better driver for it.
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