My NA answer with FM suspension and sticky tires? Umm, yeah. It corners like nothing else.
I owned a couple of Imps back in the day and that picture brought back memories. Swing axle suspension and autocross do not go together very well!
Nick (Not-Stig) Comstock wrote: I'm not convinced body roll equals poor handling. There is more to it than that.
I'm convinced that a lock of body roll probably means poor handling.
If the suspension doesn't move, it gets upset easily.
That's the Chesapeake Bay there in the background, but it is not as close as it appears in this picture.
Nick (Not-Stig) Comstock wrote: I'm not convinced body roll equals poor handling. There is more to it than that.
I agree 100%. But it's visible, so everyone is an expert on it The amount of moaning over the visible roll in the new Miata is considerable.
Nick (Not-Stig) Comstock wrote: I'm not convinced body roll equals poor handling. There is more to it than that.
Nobody so far has implied that it does. Its weight transfer,and it all depends on how well the weight transfer is managed. Chapman was another that called swaybars a crutch for people who did not know how to design a suspension.
I believe it was Smokey Yunik that said"Any suspension will work if you don't let it"
In reply to NOHOME:
All the examples of ill handling have shown visible amounts of body roll. So naturally I came to that conclusion. I guess it's hard to show a visual representation of ill handling in a picture so I guess I'll say fair enough.
NOHOME wrote: I believe it was Smokey Yunik that said"Any suspension will work if you don't let it"
Herb Adams was wrong about a lot of things, but he was right when he pointed out that suspension geometry does not matter if you don't allow it to move.
That's why I always got a real kick out of the Honda guys who would boast about their "superior" suspension geometry, for cars that were slammed and stiffened so the suspension had two inches of real travel. Well heck at that point you may as well have swing axles or fixed trunnions or something.
Peeve: Body roll is not weight transfer. That is to say, weight transfer will happen any time the center of gravity is not at ground level. Body roll is just a function of how far away the CG is from the roll center, divided by how stiff the suspension is. And no, you don't want to design a suspension where the CG and roll center are the same height, that is what a swing axle suspension is, and Bad Things Happen when the signs get reversed and the roll center moves higher than the CG. (Google "swing axle jacking"...) More important is a stable roll center, or at least one that moves smoothly and predictably.
My car has g-force Rivals (not pictured), so, yes it does.
Transitioning, well, that's another matter.
Easy recipe: Increase your roll stiffness until the roll is gone, then increase your grip until it comes back. Repeat until you run out of suspension or tire. Just watch out for bumps.
Knurled wrote:Nick (Not-Stig) Comstock wrote: I'm not convinced body roll equals poor handling. There is more to it than that.I'm convinced that a lock of body roll probably means poor handling. If the suspension doesn't move, it gets upset easily.
you've never autoX'ed a shifter kart have you ?
In reply to wbjones:
No but I tried driving the kart in GT5 on the Nurburgring because of course I did.
Karts and top-tier racing vehicles get to drive on supersmooth perfectly groomed tracks. They are invalid to the real world.
the karts that autoX with us aren't driving on super smooth groomed tracks
as a matter of fact even with rib protectors the drivers are nearly in tears after each run … but they keep coming back for more
Knurled wrote: In reply to wbjones: No but I tried driving the kart in GT5 on the Nurburgring because of course I did. Karts and top-tier racing vehicles get to drive on supersmooth perfectly groomed tracks. They are invalid to the real world.
Huh, I thought it was implied we were talking about courses, not DD pavement.
Body roll doesn't equal poor handling, there just happens to be a strong correlation between the two. The reason is that few cars have their suspensions designed to work well with large amounts of body roll, and cars with no sporty aspirations tend to have very soft suspension. So there are a lot of poor-handling cars with tons of body roll out there.
When you're designing a car's suspension, after you decide on dimensions like ride height and track width, you decide about how much body roll the car should have when cornering at the limit, and that becomes the target for your camber curve. You could design a car with a large amount of body roll and a camber curve to suit, but it's a very unusual thing to do when you can just slap hard springs on the car. Fast drivers like a harder suspension and it's easier to design for less suspension travel (getting closer to Chapman's "any suspension can work, if you don't let it")
McLaren doesn't believe in hard springs on their road-going supercars. Recently they've been able to get the best of both worlds with FRICS, but before that they simply put soft springs on their cars and gave them suspension geometry designed for large amounts of body roll:
There's another pic I'm trying to find of this car cornering, where you see the inside wheels and it looks like they're in full droop. Or if you play NFS:HP2, that game realistically depicts how much body roll the car has.
z31maniac wrote:Knurled wrote: In reply to wbjones: No but I tried driving the kart in GT5 on the Nurburgring because of course I did. Karts and top-tier racing vehicles get to drive on supersmooth perfectly groomed tracks. They are invalid to the real world.Huh, I thought it was implied we were talking about courses, not DD pavement.
that's what I was talking about … autoX courses … not many of them are supersmooth (sic) perfectly groomed tracks
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