09-22-2019, 03:02 PM | #177 | |
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In general terms, on a traditional vehicle that is steered by the front wheels, the rotation axis does not pass through the cg, it passes through the center point of the rear axle. Imagine the front wheels steered at 90 degrees and it becomes very obvious. Mid engines cars are so nimble because they have a lower natural moment of inertia AND because they are rear weight biased (cg closer to the rear axle), both of which contribute to reduce the total inertia when the vehicle changes direction. On the other hand, front weight biased cars are know to understeer because the front tires need to work that much harder to get the car to change direction due to the cg being far way from the rear axle. This is only entirely true when the front and rear slip angles are equal. When the front and rear slip angles are varied to different degrees, it changes the location of the rotation axis which alters how the car behaves. This is why mid and rear engines cars can become very tricky in oversteer situations. When the rear axle significantly looses grip, the rotation axis moves from the rear axle to the front axle of the car, with the cg being farther back it acts like a pendulum and makes recovering the oversteer that much more difficult. Hence why these cars have the reputation to "snap oversteer". In race car design, ideal weight distribution is often quoted to be in the 40-60 to 35-65 range. 50-50, or worse, front weight bias, is not desirable for optimal handling.
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Previous cars: M4cs 2019 F82 Limerock Grey / M4 2015 F82 Silverstone / M3 2008 E92 Silverstone / M3 2002 E46 Carbon Black Last edited by CanAutM3; 09-22-2019 at 04:25 PM.. |
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09-22-2019, 06:10 PM | #178 | |
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We're getting deep into it now! |
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09-23-2019, 12:54 AM | #179 | |
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But 911 layout is also 'wrong' is Porsche found out years ago That's why >2017 911 RSR has a 'midengine' and that's why F1 cars have midengines. Regarding comment on the wintertyres set I have: More times than not there are drifttyres on that 18"wheelset I have . It has nothing to do with thread depth of what I'm feeling but all with the weight of the rims + tyres. You do feel lighter rims. But this is the internet which means a lot of confusion and assumptions. Cheers Robin |
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09-23-2019, 01:08 AM | #180 |
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About midengines, Lotus didn't(doesn't atm??) provide Exige with an LSD because the car got more into UNDERSTEER than Lotus engineers wanted, but it's in the options list.
Mid engined cars and 911(older ones tell me about it) do have initial understeer too. And sometimes even more than our beloved M2/C on track (been there done that....). Mainy because of that fabulous diff we have which makes the nose point in even more than you even wish. When tyres are on temp that is GT4 PDK vs M2CS , GT4 anytime! And on my 'dreamcarlist' 991.2 GT3RS is number one no worries. Best sportscar on sale today. Cheers Robin |
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09-24-2019, 12:27 PM | #181 |
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Sport Auto's lap on YouTube today:
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09-24-2019, 01:19 PM | #182 |
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Thanks for the heads-up. Now added to the first post of this thread.
Also gets us an idea how the M2 CS sounds inside the cabin space when under load. 02:08: gong signal - M2 CS went into 'limp mode' after the hot lap (or right before finishing it).
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09-24-2019, 01:59 PM | #183 | |
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09-24-2019, 02:21 PM | #184 |
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Yup. Text that pops up on the screen 02:06-02:10 mentions that the car was running on empty. You hear the sudden power drop (going into limp mode) in the straight line at 02:06.
So hot lap test result: with almost no fuel weight and with a few moments of limp mode right before the finish line.
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09-24-2019, 02:49 PM | #186 |
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Sure does. Looks like a proper M car and a workout at the limit. Lively handling/balance = actual, lasting entertainment value on track. DSC off mandatory for pace. Sign me up.
Those who love it should get it while they can. Next gens w/ M xdrive will be a different experience. He’s up one gear and much lower rpm out of a few corners where I would have expected a gear down. Clearly has mega grunt. Sounds good, will look the part, plenty fast. Drop 1-2 seconds off of that lap time in lower temps. https://fastestlaps.com/tracks/hockenheim-gp Not sure what there is to complain about.
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09-24-2019, 04:58 PM | #187 |
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The performance of the CS should be no secret since the M2C with the M4CS stock tune would have even more power. There are plenty of people running the CS tune. The suspension would be different but the power should be similar.
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09-24-2019, 05:10 PM | #188 | |
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09-24-2019, 05:12 PM | #189 | |
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Length and wheelbase
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Length and wheelbase:
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09-25-2019, 01:23 AM | #190 |
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Sport Auto's lap on YouTube:
At the end of the lap enginepower is gone, because (stated by Sportauto) in long right turns with a tiny amount of fuel in the tank power cuts off: limp mode. Time difference 0.xxxs(?) I can't read. 0.5s according to Sportauto( Comments below YT video) So this CS had not a full tank of fuel thus being even lighter than the M2 Comp(?) *Conspiracy Theories galore* Cheers Robin |
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09-25-2019, 08:45 AM | #191 |
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Seeing the video over and over again I'm under the impression, that M2CS testcar had a bit more than '450PS' in that kind of hot weather, I guess >480PS.
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09-25-2019, 03:23 PM | #194 |
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What I would expect from a car with M-performance bits attached. They just aren't trying hard enough but will probably sell them because its still somewhat reasonable.
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09-25-2019, 04:52 PM | #195 |
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09-25-2019, 07:57 PM | #197 | |
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The reason for the optional LSD on the Exige is that for road driving you don't need it. However on the track the LSD is definitely an advantage. I frequently track with other Exiges that are virtually identical cars apart from the LSD and I get out of the corners harder.
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09-25-2019, 11:15 PM | #198 | |
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