Jetboy
New member
I think it's worth noting that high speed desert is still mostly low speed driving. The average speed as per the Toyota article for a Baja 1000 win in the stock class is 28mph.
Intuitively to me the basic physics of high speed desert racing would suggest that sway bars don't matter to any individual impact and serve to balance body sway. A sway bar's effect on one side hitting a bump at high speed will be small as compared to the shock force resisting compression. For example a single bump that's 6 inches high with a 50lb wheel/tire at 60mph would have an average force of around 6,000lbs over .01 second in the vertical direction. Probably reaching instant force of at least double that. The KDSS sway bar would apply somewhere in the range of maybe 300lbs of resistance <- I don't know what the spring rate of the KDSS bar vs the TRD Pro/SR5 bar is, but what matters here is the difference between the two. So let's say 150lbs? The remaining force will be resisted by the inertia of the vehicle (I'm assuming minimal transfer to the vehicle) the shock absorber, coil spring, and tire will all act as a unit to absorb the impact force and apply a force in reverse to the upward motion of the tire and return it back to the ground. In those instances the sway bar will have almost no meaningful influence on the short term (.01 second) motion of the system for any individual bump. Where it helps is to apply a small force over a longer time period. For example through a series of 200 bumps over 1 second it will apply a force to keep the body stabilized side to side.
My general thought here is that on a single rock or bump at high speed with the stock 4runner suspension I don't think anyone, whether it's Ivan Stewart or a soccer mom, could identify any difference between KDSS and the SR5 sway bar. A very minor valve shim difference would have more impact on high speed driving. The difference in rotational mass of the bars might have as much or more impact on high speed impacts. On the flip side the difference that is pretty significant on the street would offer similar benefit on the dirt to the extent you've got enough traction to corner at high speeds.
My biggest issue with KDSS is that it's kind of a half measure on the 4runner. The LC200 version is a lot better. It offers limited benefits with short pistons and a pretty basic set of rubber bushings for joints.
Intuitively to me the basic physics of high speed desert racing would suggest that sway bars don't matter to any individual impact and serve to balance body sway. A sway bar's effect on one side hitting a bump at high speed will be small as compared to the shock force resisting compression. For example a single bump that's 6 inches high with a 50lb wheel/tire at 60mph would have an average force of around 6,000lbs over .01 second in the vertical direction. Probably reaching instant force of at least double that. The KDSS sway bar would apply somewhere in the range of maybe 300lbs of resistance <- I don't know what the spring rate of the KDSS bar vs the TRD Pro/SR5 bar is, but what matters here is the difference between the two. So let's say 150lbs? The remaining force will be resisted by the inertia of the vehicle (I'm assuming minimal transfer to the vehicle) the shock absorber, coil spring, and tire will all act as a unit to absorb the impact force and apply a force in reverse to the upward motion of the tire and return it back to the ground. In those instances the sway bar will have almost no meaningful influence on the short term (.01 second) motion of the system for any individual bump. Where it helps is to apply a small force over a longer time period. For example through a series of 200 bumps over 1 second it will apply a force to keep the body stabilized side to side.
My general thought here is that on a single rock or bump at high speed with the stock 4runner suspension I don't think anyone, whether it's Ivan Stewart or a soccer mom, could identify any difference between KDSS and the SR5 sway bar. A very minor valve shim difference would have more impact on high speed driving. The difference in rotational mass of the bars might have as much or more impact on high speed impacts. On the flip side the difference that is pretty significant on the street would offer similar benefit on the dirt to the extent you've got enough traction to corner at high speeds.
My biggest issue with KDSS is that it's kind of a half measure on the 4runner. The LC200 version is a lot better. It offers limited benefits with short pistons and a pretty basic set of rubber bushings for joints.
