XRAY - Model racing cars

Just wondering what some of the factory guys do for setup at the beginning of a race when grip is low, then what you look at changing as grip increases?

Cheers

When a carpet track is green or the layout has just been changed, I will generally look for a little more rear grip so the car will be more consistent and easier to drive until grip comes up. As grip gets better and the track becomes more consistent, I undo those things to make the car rotate again. Usually I will adjust flex with the topdeck setting, or by using split arm mounts instead of solid, etc. You can also sauce differently, longer for more traction but less when grip is high.

I pretty much always run a 2k rear diff on carpet in 17.5 but my friends often adjust their rear diff to the track, starting at around 3k when grip is low and sometimes going as high as 10k when traction is good. I've tried doing that too, but I personally like how the 2k feels on corner entry no matter what the grip is like.

Hope this helps

Hey Luke,

Flex can be kind of funny. More flex can help in lower grip situations as the car will generate more overall traction, and it can help prevent tipping or snap-roll in high grip conditions. Less flex will be more direct and responsive to input. I would suggest going with more flex when grip is low, and less flex when the grip is high, but be careful to watch for the car getting tippy when going to a stiffer setting in high bite conditions. If it does, you may try either gluing the front sidewalls, or going slightly softer on the topdeck.

I don't mess with the roll center too much anymore. I used to run the rear .5mm low to induce roll, which to me reduced side bite in high grip conditions. My friends all disagreed with me but to me it worked, especially in high speed corners. On the 2016 I've been trying to reduce chassis roll, so I'm currently sticking with the middle roll center.

I've recently been playing with the rear track-width and found that making the rear narrow increases rotation when the grip is high. When grip is medium or low, the narrow setting I think makes more rear traction.