i just got, on loan, a xenon r2 from a friend a few weeks ago. i am just trying to dial it in for him. after rebuilding the car from the ground up, i developed a few questions and comments
1) what are all of the available castor block (c-hub) options for this car? who makes them, what material, and most important...what is the castor angle?
i saw the recent posts that the xenon c-hubs are 7*. i might agree, but i do know that the graphite variety that his parts box is littered with are not 7*. they are closer to 4 or 5. i assume that these are stock blocks, but are stock blocks different for the r1, r2, and r3? what about the square front hubs? will any other manufacturers c-hubs work correctly? fyi - rclab, and kyosho tf4 series fit quite well, but the kingpin hole for both is about 1.5mm offset to the wider.
2) the shocks really do suck. they have to be assembled to produce a mild vaccum at full extension. that kills droop settings beyond that which use the distance of the spring preload. i'm sure they are fine on the track, but i don't like the lack of volumetric compensation.
3) what is the physical explanation for the performance difference between the long and mid span arms? it must all be related to the dynamic change in roll center during chassis roll conditions, since the camber links can also be modified to produce a similar camber gain curve for both arms.
from a design standpoint, i have always liked the cars with long arms. like steve pointed out, with long arms the mechanical advantage at the wheel is reduced, so you can run softer springs to get the same wheel rate. additionally, it provides better resolution at the shock so that slop in the linkage is less evident, and there is more piston movement for a given wheel travel. with all the roll center options available, is it not possible to the long arm car to respond like that of the mid? a high roll center can increase responsiveness. has anyone tried this before going to the shorter arms?
well, that'll do for now.
one last comment - the car is brilliant on may levels. so much so, that i am scrutinizing the suspension design because i intend to use it on some prototype stuff. just like the atlas team is!
thanks for your time guys.