177mph

Just for discussions sake:

Lets just say that you had the directional stability turned off on your gx470 and you hit a patch of oil on the road and your GX somehow got sideways. Then the truck hit dry asphalt and the weight of the truck combined with the higher center of gravity started to make the truck tip over.

Would it be better to have the shocks in full soft or full hard in that situation?

I "think" having the suspension in sport mode would make the truck less likely to tip. Opinions?

DSW

I would not even like to be in that position to find out

GS3Tek

iTrader: (8)

For discussions sake, I would say HARD also b/c of less body roll.
You see can this when you take corners on the hard setting, the gx feels more stable than the soft setting. Will there be a demo?

<VENOM>

Just remember when the Insurance company ask how it happen, you hit a deer, jammed the brakes but hit a slick spot and spun the truck and then it flipped, not your fault, covered by compresive and when they ask where the deer is, just say it got up and limped into the woods

bunka

Of course this would depend on the actual speed you were traveling. If you were able to somehow get the GX up to your moniker's reputation, the settings would not matter in the least. My question would be "Does the dear make any noise when you hit it if you are in the woods alone"?

177mph

A GX travelling at 177mph would be dangerous travelling in any direction!!!

Donger

Hmmm. If you are turning the vehicle, the sport setting minimizes normal body roll. But if you are at the point where you are going to flip, would the stiffer settings just cause it to go over? Perhaps the softer setting in this case might absorb enough impact to keep the weight transfer from reaching that critical point in our hypothetical situation. If you look at cars flipping on the stupid criminal shows on TV, it seems they go over when the weight gets to a point where the suspension is no longer working and the tires are pushing down from the sidewall. If the suspension was a bit softer, maybe it would allow the vehicle to hold for just a bit longer and avoid the flip.

But I hope to never find out.

tetra7

Suspension in firm mode to prevent body sway...think of a lever arm with a damper attached to it as an engineering exercise.

177mph

But the softer setting might allow the truck to lean farther without tipping? Hmmm

bunka

I think we would need to go the extremes in order to determine which mode makes the most sense. Think of the "sport" suspension as having NO motion. Think of the "comfort" setting as being more like a Marshmellow (Can absorb ANYTHING). In these extreme settings, I would think that the soft setting would absorb LOTS of pressure. The truck might lean but the suspension would allow it. In contrast, the hard setting would not allow ANY motion AT ALL. At the first abrasion, the truck would flip. This brings us to the final component of the equation............ FRICTION. Any friction at all and the super stiff flips almost immediately whereas the super soft suspension absorbs the shocks. If ZERO friction, then the stiff would be more resistant since it would never "lean". So that answer does not lie in which suspension but rather in which surface your sliding across. If the surface is dirt (typical), the softer suspension should be more resistan. If the suface is ICE (a-typical), the stiff suspension would be more resistant. I guess the only question I really have is the geography of the test location. Is it in siberia or honduras?

gs400jon

The tires are basically a non factor in this comparison, since the friction of the tire/road surface is the same regardless of the suspension setting. You remember the Consumer Reports tests on the tipping SUV's? The soft suspension allowed extreme the body roll, changing the center of gravity and once that has started to happen, soft springs cannot prevent the inevitable. The Sport setting keeps the body upright, with minimal body roll and therefore, minimal center of gravity shift. Race cars use stiff suspension and are builf as close to the ground as the rules allow, so there must be a good reason doing that.

bunka

I understand performance cars VERY well. I agree that stiff suspensions help keep wheel grounded. I guess I'm not so concerned about the tires, but rather the motion dynamics. I agree that a soft suspesion would allow significant body movement. Once that movement occurs (past a certain point), the truck would be more likely to roll. However, if the truck had "super tight" suspension, it could roll if it hit a minor patch of friction. The truck will ALWAYS weigh the same. The real factor is how quickly the angle of attack exceeds the CG. Going 40MPH and moving from frictionless to frictionfull adhesion would cause the soft setting to move a little and retain a reasonable CG. The hard setting may prevent the motion (at first), but once the CG level was approached, the truck is toast. Moving at 100MPH either setting would result in totaling the truck. I guess the real question is "at what speed does the inertia overcome the CG in each setting?" I don't think I want to find out.

SacKen

Dang... I'm gone for a month and y'all get all smart and edumicated on me with a brain-teaser

gs400jon beat me too it... I think we all agree that the reason you flip is because your CG shifts past the vertical plane of the tires. The tire friction with the road is pretty much the same for both cases. A soft suspension would more easily allow the inertia to shift the CG past the bad point. Stiff suspension would counteract the inertia more than the soft suspension allowing your speed to be a little higher before flipping occurs.

I once was reading an article about some of the different computer controlled safety systems in cars today. I think one of them mentioned that if too much side leaning was detected that the computer would automatically stiffen the suspension on one side. I wish I could remember where I read that article.

Now I wonder how much more speed would it allow you? Anyone with a physics book that doesn't have 10 years of dust on it like mine?

CivicFerio

A stiffer suspension damping setting will lessen transient time but does not limit total body roll. Stiffer damping only changes the initial behavior of the supension that is why we feel a more crisp steering feel and braking.

Tire load transfer is also faster with a stiffer damping. On race cars we can alter turn in behaviour from turn in understeer to turn in over steer by changing the damping settings of the front and rear shocks. While on steady state cornering we can only play with the spring rates and swaybars to change the characteristics.

Back to the original question.

I would set the suspension to full stiff and over inflate the tires if permitted. In theory this would lessen the initial roll of the body and keep the CG from migrating. The over inflated tires will also result in a stiffer but smaller contact path in hope of loosing traction and sending the truck to a spin instead of hooking up and flipping over.

Charleston

177mph

Ok - I'm going to go out and over inflate my tires and set the suspension to sport. Then I'll turn off the esp - and look out!! Test dummy!

Just kidding....