Your right-you cannot turn Active stearing off but.
05-08-2007, 09:23 PM
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So I cannot find that other thread where I mentioned disabling DSC also disables active stearing. Well I checked again and I was slightly wrong-and this is where I am still confused. I did not realize how many components there are to AS! And disabling DSC disables SOME of them. Specifically like someone mentioned it disables the intervening function of activing stearing that works in conjunction with DSC to stablize a car in a situation where you are losing control-so makes sense this aspect gets disabled.
However among other features-I am wondering if the feature that "steering tightens as you go through corners-and more lateral forces gives you tighter steering"-that is paraphrased but is a feature of active steering to tighten up the steering as corners are more severe. Now this seems like a compensating mechanism but does this stay active as well>? Or is simply the basic features of AS-making the wheel less/more direct steering enabled?
Also can anyone explain AS in laymans.
I mean at slow speed/parking lot-you turn the wheel less. Makes sense good.
But at high speeds you have to turn the wheel more in order to turn? Would you not want a "tighter" wheel where you would barely have to move the wheel in order to point it the direction you want to go? I mean you do not want to have to make huge turns when you are going 100mph?
And why does bmw just not making steering super "tight" in all speeds. I love a really tight steering wheel-you seem in best control. But excuse my mistake.
However among other features-I am wondering if the feature that "steering tightens as you go through corners-and more lateral forces gives you tighter steering"-that is paraphrased but is a feature of active steering to tighten up the steering as corners are more severe. Now this seems like a compensating mechanism but does this stay active as well>? Or is simply the basic features of AS-making the wheel less/more direct steering enabled?
Also can anyone explain AS in laymans.
I mean at slow speed/parking lot-you turn the wheel less. Makes sense good.
But at high speeds you have to turn the wheel more in order to turn? Would you not want a "tighter" wheel where you would barely have to move the wheel in order to point it the direction you want to go? I mean you do not want to have to make huge turns when you are going 100mph?
And why does bmw just not making steering super "tight" in all speeds. I love a really tight steering wheel-you seem in best control. But excuse my mistake.
05-08-2007, 09:37 PM
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Originally Posted by sleepyca31' post='422431' date='May 8 2007, 10:23 PM
So I cannot find that other thread where I mentioned disabling DSC also disables active stearing. Well I checked again and I was slightly wrong-and this is where I am still confused. I did not realize how many components there are to AS! And disabling DSC disables SOME of them. Specifically like someone mentioned it disables the intervening function of activing stearing that works in conjunction with DSC to stablize a car in a situation where you are losing control-so makes sense this aspect gets disabled.
However among other features-I am wondering if the feature that "steering tightens as you go through corners-and more lateral forces gives you tighter steering"-that is paraphrased but is a feature of active steering to tighten up the steering as corners are more severe. Now this seems like a compensating mechanism but does this stay active as well>? Or is simply the basic features of AS-making the wheel less/more direct steering enabled?
Also can anyone explain AS in laymans.
I mean at slow speed/parking lot-you turn the wheel less. Makes sense good.
But at high speeds you have to turn the wheel more in order to turn? Would you not want a "tighter" wheel where you would barely have to move the wheel in order to point it the direction you want to go? I mean you do not want to have to make huge turns when you are going 100mph?
And why does bmw just not making steering super "tight" in all speeds. I love a really tight steering wheel-you seem in best control. But excuse my mistake.
However among other features-I am wondering if the feature that "steering tightens as you go through corners-and more lateral forces gives you tighter steering"-that is paraphrased but is a feature of active steering to tighten up the steering as corners are more severe. Now this seems like a compensating mechanism but does this stay active as well>? Or is simply the basic features of AS-making the wheel less/more direct steering enabled?
Also can anyone explain AS in laymans.
I mean at slow speed/parking lot-you turn the wheel less. Makes sense good.
But at high speeds you have to turn the wheel more in order to turn? Would you not want a "tighter" wheel where you would barely have to move the wheel in order to point it the direction you want to go? I mean you do not want to have to make huge turns when you are going 100mph?
And why does bmw just not making steering super "tight" in all speeds. I love a really tight steering wheel-you seem in best control. But excuse my mistake.
It changes the the ratio of the steering. So when parking with AS you may 3/4 turn to lock, whereas without you may need 1 1/2 turns to lock causing the hand over hand action.
Earlier CIP versions had AS ratios set higher at higher speeds resulting in sometimes un-natuarl behavior when cornereing and many a curbed wheel. This was fixed and improved over time.
The only time I notice AS is when I park a car or make sharp right turns in car that does not have it. The hand over hand is a pain.
05-09-2007, 05:15 AM
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Originally Posted by sleepyca31' post='422431' date='May 9 2007, 01:23 AM
And why does bmw just not making steering super "tight" in all speeds. I love a really tight steering wheel-you seem in best control. But excuse my mistake.
cheers
vern
05-09-2007, 07:11 AM
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Originally Posted by sleepyca31' post='422431' date='May 9 2007, 01:23 AM
Also can anyone explain AS in laymans.
I mean at slow speed/parking lot-you turn the wheel less. Makes sense good.
But at high speeds you have to turn the wheel more in order to turn? Would you not want a "tighter" wheel where you would barely have to move the wheel in order to point it the direction you want to go? I mean you do not want to have to make huge turns when you are going 100mph?
And why does bmw just not making steering super "tight" in all speeds. I love a really tight steering wheel-you seem in best control. But excuse my mistake.
I mean at slow speed/parking lot-you turn the wheel less. Makes sense good.
But at high speeds you have to turn the wheel more in order to turn? Would you not want a "tighter" wheel where you would barely have to move the wheel in order to point it the direction you want to go? I mean you do not want to have to make huge turns when you are going 100mph?
And why does bmw just not making steering super "tight" in all speeds. I love a really tight steering wheel-you seem in best control. But excuse my mistake.
http://forums.e60.net/index.php?showtopic=2103
Basically there is a trade-off on all cars with regard to steering input and vehicle speed. On a fixed-ratio steering system (non-AS), the faster a car goes, the less steering input it takes to change the car's direction -- that's just the laws of physics working.
When designing a performance car without AS, the engineers have to choose a steering ratio that provides the best handling through a range of speeds. If they pick a ratio that yields a "tighter" wheel (as you describe), then the car will handle well on low or moderate speeds but will be "twitchy" and unstable at higher speeds. In other words, the tight steering ratio car will be hard to keep straight at high speeds because even a small change in the steering input will cause a sudden change in direction. If the engineers pick a ratio that is not tight, then the car will be stable at higher speeds but will not handle very well at lower speeds.
AS solves this age-old problem by allowing the car to adjust the ratio as speeds increase.
Get it?
05-09-2007, 07:18 AM
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Originally Posted by Rudy' post='422529' date='May 9 2007, 11:11 AM
The concept of AS is explained fairly clearly in the FAQ:
http://forums.e60.net/index.php?showtopic=2103
Basically there is a trade-off on all cars with regard to steering input and vehicle speed. On a fixed-ratio steering system (non-AS), the faster a car goes, the less steering input it takes to change the car's direction -- that's just the laws of physics working.
When designing a performance car without AS, the engineers have to choose a steering ratio that provides the best handling through a range of speeds. If they pick a ratio that yields a "tighter" wheel (as you describe), then the car will handle well on low or moderate speeds but will be "twitchy" and unstable at higher speeds. In other words, the tight steering ratio car will be hard to keep straight at high speeds because even a small change in the steering input will cause a sudden change in direction. If the engineers pick a ratio that is not tight, then the car will be stable at higher speeds but will not handle very well at lower speeds.
I thought the standard servotronic steering system had some "variable assist" built into it as part of all E60s regardless of whether AS is an installed option or not. If so, does it just reduce the forces needed to turn the steering wheel? That's my guess - so the front wheels would still turn the same # of degrees based upon the same angular turn of the steering wheel, however the force needed to do so could be different. Looking for someone with greater technical knowledge to comment, thanks.
AS solves this age-old problem by allowing the car to adjust the ratio as speeds increase.
Get it?
http://forums.e60.net/index.php?showtopic=2103
Basically there is a trade-off on all cars with regard to steering input and vehicle speed. On a fixed-ratio steering system (non-AS), the faster a car goes, the less steering input it takes to change the car's direction -- that's just the laws of physics working.
When designing a performance car without AS, the engineers have to choose a steering ratio that provides the best handling through a range of speeds. If they pick a ratio that yields a "tighter" wheel (as you describe), then the car will handle well on low or moderate speeds but will be "twitchy" and unstable at higher speeds. In other words, the tight steering ratio car will be hard to keep straight at high speeds because even a small change in the steering input will cause a sudden change in direction. If the engineers pick a ratio that is not tight, then the car will be stable at higher speeds but will not handle very well at lower speeds.
I thought the standard servotronic steering system had some "variable assist" built into it as part of all E60s regardless of whether AS is an installed option or not. If so, does it just reduce the forces needed to turn the steering wheel? That's my guess - so the front wheels would still turn the same # of degrees based upon the same angular turn of the steering wheel, however the force needed to do so could be different. Looking for someone with greater technical knowledge to comment, thanks.
AS solves this age-old problem by allowing the car to adjust the ratio as speeds increase.
Get it?
05-09-2007, 07:19 AM
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Apologies on formatting of my last post - got my comment / question inserted in the middle of the quote of previous post.
05-09-2007, 07:22 AM
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Originally Posted by 1994_RX-7_Tour' post='422534' date='May 9 2007, 11:19 AM
Apologies on formatting of my last post - got my comment / question inserted in the middle of the quote of previous post.
Just copy and paste the contents of the second one into the first one (or vice versa...)
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