XRAY - Model racing cars

Hi All

Was checking my car over the other day and noticed that the width of tha back wheels(from the bottom of the tyre) is about 6 mm narrow than the front? Rear is 292 front is 298. Is this right as i'm having problems with the cars back end always stepping out.
Any help

NZXB8 Driver

Yes, I noticed that also but not as much. I measured for about 3mm difference.

For sometime now I am using Mugen Prospec Aluminum Rear Hub to obtain longer upper link. I try to copy Mugen Roll Center because I in my opinion the dynamic of Mugen car is still the best.

Btw, because I'm using Prospec Hub now I could adjust the rear track width by approximatelly 2mm.

Now, I set the rear track width at 282.6mm with 3 degree of toe-in, measured at the hexagonal while the arm is parallel to the ground.

Maybe the rear track being narrower than optimum is deliberate by x ray in the design because they knew the hop up rear hubs and hexes where coming which allow you to increase the rear track,......... probably to the legal limit. So maybe if you want the best track you need to buy the hop ups

ok then my problem is that the rear is all over the place and i through that changing the rear width would fix this as have tryed different diff oils and shock oils. was running 5/7/3 running on grass with 35wt in shocks and using turbo rats or grips form power tires. Using 3mm rear and 2.6 front sray bars.
Any hepl or ideas please trying ryan donavans setup next meeting as he runs on grass
cheers

I have just completed a full weekend of testing on grass and this is the setup we finished up with:

FRONT END
Diff Oil: 7000 (no small o-rings)
Piston: 1.5 Straight
Oil: 500wt (Xray)
Spring: Light Blue
Pre-Load: 9mm - unis level
Upper Shock Position: #7
Lower Shock Position: #2
Anti-Roll Bar: 2.8mm
Outer Camber Link Position: #1
Droop: 24mm (measured on a proline rim)
Castor Eccentric: +2
In-Board Toe: "0" bushing (1 deg toe out)
Roll Center: "0" bushing front and rear
Kick-up: 5 degrees
Toe Out: 1 degrees
Upper Arm Position: small spacers in back of arm
Camber: -5 degrees

CENTER
Diff Oil: 10000 (no small o-rings)
Ackerman Position: Middle
Servo Saver: Medium
Brake Bias: Rear
Clutch Bell: 13T
Spur Gear: 46T
Clutch Spring: 1.0mm
Clutch Shoe: Aluminium

REAR END
Diff Oil: 3000 (no small o-rings)
Piston: 1.5 Straight
Oil: 500
Spring: Light Blue
Pre-Load: 6mm - unis level
Upper Shock Position: #9
Lower Shock Position: #2
Anti-Roll Bar: 3 mm
Outer Camber Link Position: #3
Inner Camber link Position: #2
Upright Roll Center: #1
Droop: 14mm (measured on a proline rim)
Rear Toe-in: 2 degrees
Wheelbase: long
Anti-Squat: 1 degree "0" bushing
Camber: -5 degrees

We found this setup very easy to drive, I might suggest you try taking some of the droop out to allow the car to change direction much faster, if there are lot of quick tight sections you might also like to change the roll center on the front to "1"down on the bushing and if you still need more steering try 4 degrees kick up.