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05-01-2013, 07:15 PM | #1 |
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Understeer in the M - it achieves balance?
After successful negotiation on rates, the M is at the dealer getting new plugs, pads, filters etc., and I'm driving an F30 328
One interesting characteristic it has is being slightly tail happy in corners under trail braking, and (if you're really standing on it) under throttle. Which is pretty entertaining in a sort of micro-scale way. But then I started wondering why the M is set up to understeer, and this occurred to me: Maybe it's because the understeer is so easy to defeat with the S65, that if the M was more balanced or had a rear bias we would be spinning off into the sunset a la old 911s? So it becomes balanced under aggressive driving, vs. more quickly moving to oversteer? I dunno, not exactly a vehicle dynamics expert, was just curious what opinions others have. Cheers
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05-01-2013, 08:14 PM | #2 |
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Neither am i, but i always thought most (if not all) street cars are purposefully set up for understeer as understeer is a lot easier to correct than oversteer.
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05-01-2013, 08:47 PM | #3 |
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E9x does not understeer anything close to prior /M cars. Really annoying when people come here saying how much it "understeers" based solely on prior /M cars.
It was picked best drifting car; that isn't going to happen if it pushed all over the place. All the mags said its balance and may understeers at the limit, which no one should be close to on the street. . |
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05-01-2013, 09:08 PM | #4 |
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Take it to the track in stock form. It understeers.
I'm sure it's set up this way because as mentioned, you won't get yourself into as much trouble in understeer as you can with oversteer. Also, from what most of us have found out, it takes a fair bit of negative front camber, square setup, and maybe some other suspension tuning to dial it out. That's not the type of car most buyers are looking for in stock form and really the understeer is only noticeable at the track (at least to me). |
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05-01-2013, 09:51 PM | #5 |
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I don't think I made my point clearly. It's true that cars are usually set up to understeer so they're easier to control in an emergency, for a driver with less skills. But if my understanding of this 328 is accurate, it's NOT set up to understeer, it's balanced and handily quick to oversteer.
In an M3, you'd expect (hope) that the typical driver has better-than-average skills, so it's odd that BMW would set up a 328 for balance, and an M3 for understeer. So...maybe the M3 is set up for understeer simply because there will usually be enough throttle to balance it, and otherwise it would be rear-biased. Cheers
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05-01-2013, 10:37 PM | #6 | |
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05-01-2013, 10:42 PM | #7 | |
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05-01-2013, 10:45 PM | #8 | |
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05-01-2013, 11:25 PM | #9 | |
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05-02-2013, 02:39 AM | #10 |
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Does everyone find the E92 M3 has too much understeer?
While my E46 M3s had too much understeer, my E92 M3 seems really quite well balanced. I do have a few extra psis in the front tyres which improves the turn in but I doubt it makes that much difference. Sure I can make it understeer, try to carry too much speed and throttle into the corner and it will push across the road but thats not a sensible way to corner. |
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05-02-2013, 07:22 AM | #11 |
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IMO, the M3 does understeer quite a lot when pushed closer to the limit. Not something one would notice driving at 8/10th though.
When discussing the "balance" of a car, it is steady state (constant speed) balance that is implied. Therefore, I think it is important to define what steady state understeer and oversteer are. Tires, while generating lateral grip, have an inherent amount of slip. When the front tires slip more than the rears, it is understeer. When the rears slip more, it is oversteer. So yes, the M3 understeers in stock form. With a neutral car cornering at constant speed, all four tires slip equally. When slightly more throttle is applied, the weight transfers to the rear and the car understeers. If slightly less throttle is applied, weight is transferred to the front and the car oversteers. A neutral car is much easier to steer with the throttle, however it can be done to some extent with ant type of car. Power on oversteer is something not realy related to the steady state balance of the car. When way too much throttle is applied, the grip of the tire is overcome and the rear end steps out. However, when a car is more neutrally balanced (less dialed-in understeer), its takes less throttle input to overcome the rear grip. Last edited by CanAutM3; 05-03-2013 at 06:23 AM.. |
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05-02-2013, 09:00 AM | #12 | |
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1. The driver who spends the extra coin for an M3 is either a serious poser, or is a driving enthusiast. By definition, an enthusiast is someone who's more interested in the subject than average, and thus should know more about how to drive well. 2. The percentage of people who track their M3 is conservatively 5-10%. That's 5-10% more than drivers of passats, or optimal, or avalons, etc, and someone who's been even reasonably successful on the track should understand more about driving dynamics. And finally, remember that an average is just that. I didn't say there wouldn't be M3 drivers who suck, or drivers that are way beyond merely good. Cheers
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05-02-2013, 09:18 AM | #13 | |
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That's why car companies like BMW never offer aggressive suspension and tail happy handling on a road car. They may appease the 5-10% of talented drivers among their customers, but when the other 90-95% fly off the road straight onto the nearest tree trunk, the lawsuits will pile up, sales will plummet, and the company will go bankrupt. Last edited by Majin Buu; 05-02-2013 at 09:23 AM.. |
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05-02-2013, 09:47 AM | #14 | |
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05-02-2013, 10:08 AM | #16 | |
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I can see that steady state cornering at the limit will expose the cars ultimate tendency to under or over steer but who takes a corner like that IRL? I certainly don't find the car to understeer "quite a lot"...it doesn't take much of a tyre grip differential front to rear to make the car tend to oversteer rather than understeer. I wonder how much the DSC tries to balance the car in a turn near/at the limit by inducing understeer? |
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05-02-2013, 10:13 AM | #17 | |
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05-02-2013, 10:18 AM | #18 |
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thats a low estimate.
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05-02-2013, 10:23 AM | #19 |
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I'm by no means an expert but currently run with 'intermediate' groups on track days. I'd like a little more oversteer on the M3 but IMO feel like it's more balanced driving it hard on the track. So I'm not really complaining or planning to make adjustments, though I'm coming from Audi's so I probably suffer from traumatic understeer stress disorder...
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05-02-2013, 10:47 AM | #20 | |
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05-02-2013, 10:53 AM | #21 | |
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05-02-2013, 11:02 AM | #22 |
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