RS4: Is it any competition for the M3? (X-Post)
12-02-2006, 12:28 PM
#51
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Re: ^^the 2 posts above are getting an awful lot of views in a short time^^...
No worries, I'm used to it by now and don't take it seriously at all. For a forum about the RS4, I'd say the past 5 months have been more contentious than any time on the B7 S4 forum during the year prior.
To me that means one thing, the RS4 is that good, and it pisses off that many people. Go figure.
To me that means one thing, the RS4 is that good, and it pisses off that many people. Go figure.
12-02-2006, 12:38 PM
#52
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Okay, fine...
Didn't you say that your profession is in internal engine components? How does that make you an expert in these other matters? Now, maybe you are at that. I don't know.
But I would ask you why the constant striving by car mfgrs for increased structural rigidity? If you think it's just for a more solid body and less rattles and such, then I don't know what to say to you. So why are they going for more rigidity, coincidentally, as the performance and speed envelope keeps getting pushed farther out?
As for understanding, let some light in, Chris?
But I would ask you why the constant striving by car mfgrs for increased structural rigidity? If you think it's just for a more solid body and less rattles and such, then I don't know what to say to you. So why are they going for more rigidity, coincidentally, as the performance and speed envelope keeps getting pushed farther out?
As for understanding, let some light in, Chris?
12-02-2006, 12:42 PM
#53
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Agreed...
it is that good and it's where the action is right now.
The people who are not RS4 ownwers, and have to get behind the wheel of their car everyday, well some of them have a problem with that, it seems.
I drive an S4, and I don't have RS4 envy. On the contrary, I have admiration for those of you who have made the choice to own and drive one.
The people who are not RS4 ownwers, and have to get behind the wheel of their car everyday, well some of them have a problem with that, it seems.
I drive an S4, and I don't have RS4 envy. On the contrary, I have admiration for those of you who have made the choice to own and drive one.
12-02-2006, 12:58 PM
#54
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That's a perfectly valid question...
and with a rational discussion, you'll get nothing but the same in return from me.
The two major pushes for car companies to increase the torsional stiffness of subsequent platforms is suspension response and vehicle safety. Both of these items are strongly influenced by the strength and stiffness of the platform in question. That's a pretty obvious correlation.
The fact that each stiffer (should) show fewer squeaks and rattles is simply a nice side benefit on mid priced cars and a near necessity in the upper price classes.
The reason that a stiffer platform improves suspension response is because a solid chassis keeps your suspension points stable. At extreme cornering loads (see values approaching 1g cornering under race track conditions), the suspension pickup points will move in relationship to each other under chassis flex. This makes it more difficult for the suspension to do its job properly and takes "feel" away from the car. Consider the picture below showing a car fitted with a strut tower brace.
<img src="http://www.rebmw.com/Merchant2/graphics/00000001/suspension/stb/re_cf_stb_600c.jpg">
Under cornering loads, the two points where the bar is connected on the unibody (the strut towers) will curve inwards towards each other. That's just one common area where a "soft" chassis will flex.
As I discussed though, the loads required to deflect a stiff chassis are so incredibly high, that you're really only going to notice the difference under VERY high stress conditions. This means race track work at very high G cornering loads.
This is where your theory doesn't work out. At Autobahn speeds, you are not cornering hard. If you are attempting to take 0.9 g corners at 180 mph, you are absolutely crazy. No one does this, at least for very long. In a straight line, it will be nearly inconsequential. The side wind loads are so small in relation to other chassis loads.
The bottom line is that during high speed triple digit driving, you are not stressing the chassis in a manor where the difference becomes relevant.
If you are asking which chassis would be more capable going around the Nurburgring, that answer is very clear. Here you could certainly capitalize from the B7 platform's superior stiffness...but no one has ever said otherwise.
To your other points, the only reason a car would "blow off" the Autobahn is due to bad driving or poor aerodynamics/lift coefficients. The latter has not been a problem for any modern day Audi.
I hope that clears some things up for you.
The two major pushes for car companies to increase the torsional stiffness of subsequent platforms is suspension response and vehicle safety. Both of these items are strongly influenced by the strength and stiffness of the platform in question. That's a pretty obvious correlation.
The fact that each stiffer (should) show fewer squeaks and rattles is simply a nice side benefit on mid priced cars and a near necessity in the upper price classes.
The reason that a stiffer platform improves suspension response is because a solid chassis keeps your suspension points stable. At extreme cornering loads (see values approaching 1g cornering under race track conditions), the suspension pickup points will move in relationship to each other under chassis flex. This makes it more difficult for the suspension to do its job properly and takes "feel" away from the car. Consider the picture below showing a car fitted with a strut tower brace.
<img src="http://www.rebmw.com/Merchant2/graphics/00000001/suspension/stb/re_cf_stb_600c.jpg">
Under cornering loads, the two points where the bar is connected on the unibody (the strut towers) will curve inwards towards each other. That's just one common area where a "soft" chassis will flex.
As I discussed though, the loads required to deflect a stiff chassis are so incredibly high, that you're really only going to notice the difference under VERY high stress conditions. This means race track work at very high G cornering loads.
This is where your theory doesn't work out. At Autobahn speeds, you are not cornering hard. If you are attempting to take 0.9 g corners at 180 mph, you are absolutely crazy. No one does this, at least for very long. In a straight line, it will be nearly inconsequential. The side wind loads are so small in relation to other chassis loads.
The bottom line is that during high speed triple digit driving, you are not stressing the chassis in a manor where the difference becomes relevant.
If you are asking which chassis would be more capable going around the Nurburgring, that answer is very clear. Here you could certainly capitalize from the B7 platform's superior stiffness...but no one has ever said otherwise.
To your other points, the only reason a car would "blow off" the Autobahn is due to bad driving or poor aerodynamics/lift coefficients. The latter has not been a problem for any modern day Audi.
I hope that clears some things up for you.
12-02-2006, 01:19 PM
#57
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Thank you...
it does shed some light, but don't assume that I have not seen this kind of info before, many times.
I think the basic disagreement still centers around the rigidity differences, and it's significance under less than optimal conditions, of which 180 mph and high crosswinds would involve.
Despite what the driver is doing, there will always be external forces(wind, road condition, etc) that will come into play, seriously at those high speeds.
If I'm in the car at 180mph, and get hit with a sudden crosswind, then I am going to feel less of that in the stiffer car, despite what else is going on(g's, lateral forces, sudden wheel movement). And if I crash, even managing to slow the car somewhat, I will be that much better off in the car with more structural rigidity. I'm talking body here, not just chassis, and always have been!
I think the basic disagreement still centers around the rigidity differences, and it's significance under less than optimal conditions, of which 180 mph and high crosswinds would involve.
Despite what the driver is doing, there will always be external forces(wind, road condition, etc) that will come into play, seriously at those high speeds.
If I'm in the car at 180mph, and get hit with a sudden crosswind, then I am going to feel less of that in the stiffer car, despite what else is going on(g's, lateral forces, sudden wheel movement). And if I crash, even managing to slow the car somewhat, I will be that much better off in the car with more structural rigidity. I'm talking body here, not just chassis, and always have been!
12-02-2006, 01:27 PM
#59
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Be nice your majesty...
I, personally, am always so impressed with your contributions here, which usually amount to patting yourself on the back or stroking your own ego.
I'll never forget you're "hilarious" claims that the new M3 is perfectly on schedule, and that BMW has nothing to worry about with the RS4.
Keep in mind where you are here. It's an Audi forum.
Oh, and I noticed your cheap little dig at the TT above. You are so prejudiced it is blatant! Ever have anything good to say about an Audi? Any Audi?
I'll never forget you're "hilarious" claims that the new M3 is perfectly on schedule, and that BMW has nothing to worry about with the RS4.
Keep in mind where you are here. It's an Audi forum.
Oh, and I noticed your cheap little dig at the TT above. You are so prejudiced it is blatant! Ever have anything good to say about an Audi? Any Audi?