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 Post subject: Hypothetical question about handling dynamics.
PostPosted: Thu May 30, 2013 3:36 am 
First Gear
Joined: Wed Apr 10, 2013 6:43 am
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Location: Key West, Florida
What would be the effect on handling, from the perspective of autocrossing, if weight quickly transferred to the outside rear tire in turns? Would the quick weight transfer help or hurt cornering performance? Obviously, more weight on the outside rear tire might mean less weight on the inside front tire, causing it to lift. Am I correct in assuming this? Imagine the trunk were full of water 3/4 of the way up. The inertial force would cause the water to shift to the right in a left hand turn, putting more weight on the outside rear tire. What effect might this have on handling?


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 Post subject: Re: Hypothetical question about handling dynamics.
PostPosted: Thu May 30, 2013 4:53 am 
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 Post subject: Re: Hypothetical question about handling dynamics.
PostPosted: Thu May 30, 2013 4:49 pm 
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Sounds interesting, wish I could answer -- but thinking about what you propose it does sound like it'd be fun to try :)

Would be easier to break the tail end loose, at the very least...

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 Post subject: Re: Hypothetical question about handling dynamics.
PostPosted: Thu May 30, 2013 7:03 pm 
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I guess my one thought would be that having something like that move around to cause more or less weight shift would be unpredictable and may not be too helpful.

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 Post subject: Re: Hypothetical question about handling dynamics.
PostPosted: Thu May 30, 2013 11:42 pm 
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free5ty1e wrote:
Sounds interesting, wish I could answer -- but thinking about what you propose it does sound like it'd be fun to try :)

Would be easier to break the tail end loose, at the very least...


This is what I thought the answer might be. In other words, great for drifting if the suspension was set up correctly and the driver was used to it, but probably terrible for autocross.


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 Post subject: Re: Hypothetical question about handling dynamics.
PostPosted: Fri May 31, 2013 12:10 am 
Fourth Gear
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Location: Arkansas
I'm thinking even for drifting, likely bad. The issue is the way you turn now not only has to account for the corner and the tires and the suspension but now a mass that's sliding around independently of the rest of the vehicle. On corners with rapid turn in or a fast change of direction, the weight could trail loading the tires/suspension very inconsistently and make it hard to control.

If it was a lot of long, sweeping corners, then maybe it could help. But you must also consider how much the weight will slow you down and reduce handling response, and compare that against simply setting the rear suspension to be looser.

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 Post subject: Re: Hypothetical question about handling dynamics.
PostPosted: Fri May 31, 2013 12:11 am 
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Of course, if you require a similar amount of counterweight to balance the car or meet a minimum weight in the first place, then it becomes a much more interesting proposition.

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 Post subject: Re: Hypothetical question about handling dynamics.
PostPosted: Fri May 31, 2013 1:56 am 
First Gear
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The interesting part about this idea though is that body roll would not (necessarily) be the cause of the weight transfer. The car could possibly remain level throughout the turn, and yet, weight would still transfer to the rear outside corner. I'm sure, however, that the weight transfer would quickly induce oversteer, unless compensated for by suspension setup and/or the drivers skill.


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 Post subject: Re: Hypothetical question about handling dynamics.
PostPosted: Fri May 31, 2013 2:03 am 
Fourth Gear
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Weight transfers to the outside with no body roll anyway, just much less. Having a static weight in the rear will still reault in increased weight transfer to the outside rear tire in corners.

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 Post subject: Re: Hypothetical question about handling dynamics.
PostPosted: Fri May 31, 2013 2:05 am 
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James614 wrote:
On corners with rapid turn in or a fast change of direction, the weight could trail loading the tires/suspension very inconsistently and make it hard to control.


Inconsistency of suspension load. Good point. All the more to convince me that it's a bad idea. I imagine that anything that upsets the balance of the vehicle is bad for handling especially for a tight course. Thanks


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 Post subject: Re: Hypothetical question about handling dynamics.
PostPosted: Wed Aug 13, 2014 11:23 pm 
Fourth Gear
Joined: Wed Jun 22, 2005 4:07 am
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Have you been reading the manga series of Initial D? I can see how this transfer would be interesting for a drift car to experiment with, but for grip racing it seems like a bad idea. Now I wonder if you could do the opposite; have this mass set in to motion in a direction opposite of weight transfer, time it just right so that it counters the weight transfer progressively mid-corner.

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 Post subject: Re: Hypothetical question about handling dynamics.
PostPosted: Fri Aug 15, 2014 11:16 pm 
First Gear
Joined: Wed Apr 10, 2013 6:43 am
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Location: Key West, Florida
You would use the same principal as Electric Power Steering except pumping water into a chamber. You would adjust the static LPH rate and the progressive gain based on wheel position to get the right balance. Of course, going opposite lock would then cause it to go the "wrong" direction again, but the point of this system would be to avoid oversteer. Electronic stability control would probably be just as effective, if not more so, and probably add less weight. I think shocks, springs, and anti-sway bars are simple and effective enough. It's interesting for the Bat Car, however. I just like to think out of the box.


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