Is cross weight outdated?

[Mr.Kennedy777]

I am well aware. There is no reason the bump has to absorb extra load. We are way past single rate spring systems. It's been 10 years since I was there.

A bump setup isn’t a single rate spring system and I’m sure you know that. If cornering force is the same, everything else is the same, except for example pre load in the RF, more or less force will go into the bump itself because more or less of the max load is “taken up” by pre load.

[Mr.Kennedy777]

If you’re talking about running a stacked spring setup with a bump, then the same thing would apply. Less initial take up in the initial spring rate, means more to take up in the second stage and if you don’t change that, then you still have more to take up in the bump.

[Mr.Kennedy777]

All things staying the same besides pre load.

[mickley.28]

All that matters is the individual wheel loads dynamically on the track.... everyone should be able to agree on that. The cross weight at static ride height you will never see when going around the track so it doesn’t matter what the static cross weight is, but changes to static cross weight will typically effect your dynamic cross weight (wheel loads).... the exception would be changes to the left rear may or may not have a dynamic effect. So I guess both of you are correct... static cross weight means nothing to how the car will handle in the dynamic state but changes in cross weight will typically effect dynamic wheel loads. I no longer consider things like cross weight or wedge in my setup because someone with 300lbs of static wedge could easily have less dynamic wedge than someone with 0lbs of static wedge. One could put ten turns in there left rear and add over 100lbs of wedge and it might not change the way the car handles dynamically at all or it could change everything. Based off what I seen this year with jds car I would be willing to bet he’s running negitive wedge numbers and the xr1s are running over 100lbs of wedge but if you could weigh each corner as it went around the track I’d be willing to bet the dynamic numbers are much closer to eachother.

[fastford]

I agree with the above analyses , all we use static measurements for is reference points , so if we go to the track and go to tuning the car and find some speed , then we go back to shop , put on scales and make adjustments to our base , static set up. I dont have a pull down rig , but i also do a static check with right front on the bump stop , with no spring and log left rear static bite , there is some things to be gained here to. MK777 and MBR , both you guy,s are sharp , theres no doubt , but i still believe you need to use every thing you can now days......