XRAY - Model racing cars

Tony,

I've been able to get my "off the wall" setup working well. The problem now is that I just found out that the 26mm 30 shore rear tires I'm using are in rare supply unless I want to pay a higher price than I've been paying. I can still get 35 shore rears for a cheap price, so I'm looking to change the setup to get more rear traction. I'm using a 2mm front anti-roll bar, Purple front springs in the upright pos#4, the XRC chassis, standard 2.5mm upper deck and I've lightened the overall car significantly. With this setup, I believe the stiff front springs, roll bar and chassis are preventing the rear from rolling as they are combining to keep the entire car flat by keeping the left and right front arms at the same level in relation to the chassis. I've been able to get enough roll in the rear for great traction when using the now unavailable soft tires, but I've had to use light blue or softer springs with the shocks mounted on both the upper and lower inner mounting holes. I tried softer rear springs, but this was causing the car to break rear traction inconsistently and I'd rather not go to a softer front roll bar. I plan on testing with the lower rear hinge pin mounting holes to lower the rear roll center. However, I would like to know what would happen if I used the flexible upper deck with the XRC chassis (really don't want to go back to the FK chassis). Would it allow the rear to roll more independently from the stiff front (which is what I'm looking for)?