All,
I've been very fortunate to have the opportunity to test some new prototype aluminum rear hubs. They have two degree's of built-in toe in which allowed me to mount the rear arms without any shims in between them and the bulkhead. The end result provided a much easier time of mounting the arms without having to work so hard to free up any binding due to the previous pin angle. That is actually the worst of the news! The good news is that they make a definite difference on the track
Before testing at the track, I installed the new hubs and performed a cornering simulation test on my trusty HUDY setup board.
A few of us discussed this on a previous thread: http://www.teamxray.com/xforum/viewtopi ... c&start=20. The setup board testing method I used is very similar to what I've done in the past while testing front in-board toe out and can be found at the following thread: http://www.teamxray.com/xforum/viewtopi ... sc&start=0
On the setup board the results clearly show that the camber change is more stable for each rear tire during suspension compression and rebound as the car rolls toward and away from the tire. The camber gain on the inner tire is actually lessened pretty significantly. Now I know most of you are thinking like I did at first, "this doesn't mean squat since the inner rear tire is providing very little grip during cornering anyway." But the truth is that the inner rear tire provides significant traction through its narrow contact patch on the inner edge of the tire. The lightly loaded small sliver of contact patch from the inner wheel acts like a guide in the corner, provides stability and can be used to fine tune the steering characteristics of the rear end. Try reducing your rear droop and 95% of the time when the inner rear wheel rises off the track in the corner your car will do a very nice but sometimes damaging 180 degree pirouette.
On the track and with a decent setup, it would take a better than average driver to notice the rear end is much more stable throughout the entire corner. I'm certainly not an expert, but I was able to notice a difference. Before using the new hubs, with my very stiff rear spring setting, I was never able to run harder than 30mm 30 shore rear tires, or less than 2.5d rear toe in, due to infrequent & abrupt losses of traction in the rear end. During this test I was able to confirm the added stability in the rear end by running a pair of 35 shore rear tires and using only 2d of outboard rear toe in built into the new hubs. Through ten complete packs, and switching between a stock motor and a 19 turn motor, the rear end was dialed throughout the entire track. I had to further unload the rear tires by increasing my rear ride height by .5mm to provide enough steering for the higher cornering speeds of the 19 turn and still no loss of rear traction. For laughs
I even mounted my top heavy HUDY H2 body ( http://www.geocities.com/acquaba/RC/Bod ... r_Rear.jpg , http://www.geocities.com/acquaba/RC/Bod ... _Front.jpg ) and the rear end remained dialed without any abrupt changes in grip. BTW, the more stiff the rear end, the better the overall steering. This setup allows me to get on the gas much earlier in the corner and maximize the use of the one-way to pull the car out of the corners while accelerating hard.
In conclusion, the rear end is noticeably smoother using the new hubs with more predictable steering in high speed corners and no loss of traction when making large mid corner steering corrections.
I plan on testing the 1.0d & 1.5d hubs next week to see if the car continues to steer well and provide a stable rear end. If this works and I'm able to reduce the rear toe in more, I should be able to increase the acceleration out of corners and top speed down the straight.
My latest setup can be found here:
http://www.geocities.com/acquaba/RC/Xra ... _Setup.jpg
Pics of the latest Nemesis body I'm running (Purple-red-yellow-Nemesis... file names) and all other bodies I've made in the past can be found here:
http://www.geocities.com/acquaba/RC/Bodies