Roll & Pitch Stiffness

Didn't bring RCVD back home from work today, so I'll have to do this by hand again. I figure roll and pitch gradients (in deg/g) should be ballparked by the following:



Obviously that assumes my roll center is just about on the ground and on chassis centerline, likewise pitch axis about under the cg, w is really w_sprung, etc etc. For now I'm looking at ballpark values.

As an aside, anyone from work would probably be giving me a lot of shit right now about equations and documentation and all that. But you do have to have some level of analytical work and knowing what you're doing, i.e. not just welding a pile of crap together.

In any event, even with the relatively soft wheelrates of last night's 2Hz front and 2.2Hz rear sprung natural frequencies, that still gives me 1.5 deg/g in roll and 0.6 deg/g in pitch. Not too shabby! Lot more rigid than I had expected. Should let me run a pretty low ride height without bottoming the car, even if I had something outrageous like 3g of braking. Going up to 3Hz front and 3.3Hz rear yields 0.7 deg/g in roll and 0.3 deg/g in pitch.

Don't want to go too stiff in roll from just spring, so I do still have some quick tuning options from ARB's, which will hopefully be cockpit-adjustable.

Enough of spreadsheets. Hopefully in this week I can get more of the uprights fleshed out and get suspension CAD started, see what tricks I can pull with the kinematics.