XRAY - Model racing cars

We have a competition series here on carpet, where foam tyres are allowed, so most people use it. Allowed motor is stock, 13.5, grip middle, min gear ratio 4.5. I'm the only one with T4 15. I used to finish in the middle.

I started with the basic carpet setup, but it looked soft overall, so started to harden (anti roll bar, springs, etc.). But since this is influence the whole setup and other elements should probably change (shock/diff oil, roll center, etc) I would like to ask you with more experience to post a setup sheet for foam tyres for carpet. (Let say for 64 mm diameter tyres).

I see that it can not be perfect, but as a basic average setup for a middle experienced driver would be appreciated.

Thanks
Tom

Hi Tom,

I think the basic setup for carpet is for rubber tire carpet not foam, that's way it seemed soft you.

Big races around the world have not been running foam tires so the company's have gone away with a product that is based on foam carpet for touring cars.

For your shocks go 4 hole 1.1 pistons all the way around. Do 700cst in the front 600cst in the rear. Springs for the front 2.9 for the rear 2.7. Sway bar in the front 1.6. Never ran one in the rear when we raced foam. Front gear diff 1 million cst rear 20000cst. This is just a starting point for the gear diffs because we didn't have them when we run foam carpet. It was ball diffs all the way around. You will want to get the Xray aluminum chassis. Roll center and camber links are fine in the carpet basic setup sheet.

Hope this helps. Been awhile since I have ran foam TC, but this would be where I would start if I raced it again.

Thanks,
Drew

I run foam tires on carpet, but with the T4'13 in a 17.5t blinky class. Our carpet is lower grip than most but here is where I'm at:

1.1 piston all shocks, 650cst front, 550cst rear. 2.7c front spring, 2.5c rear spring. Front shocks are laid down to the bottom hole, rear shocks are 1 hole from the bottom. In the past I have also had success with 2.5-2.8 progressive springs in the front, and 2.3-2.5 progressives in the rear.

I am running kit sway bars front and rear. Mounted on the inner ball on the rear arm.

Shortest possible camber links, 2mm under inner ball in front, 1mm under inner ball in the rear.

-1deg camber all around, adjust it according to tire wear. Rotate the tires every 2 or so runs.

6mm ride height front, 5mm ride height rear, with 5mm droop over ride height front, 2mm droop over ride height rear.

I usually run a spool up front, but have run a 2.5mil gear diff. But the diff usually rotates the car too much for my liking. In the rear I run 2k cst. I also use 50mm ECS axles in front.

I use Gravity LGC compound on the tires, inner 95% on the rear, just a middle stripe on the front tires.

I also have success taking screws out from the top deck. I remove the 4 on the rear bulkhead, and 2 from the front bulkhead, keeping all 4 on the layshaft.

I run a Protoform P37R body fyi, which I find to have plenty of steering, but good balance.

Overall my car is very aggressive with a positive feel. The rear end rotates very well, but sometimes can tend to lose a little grip halfway through the corner, (hence why I don't run the front gear diff). I was going to switch to the Protoform Mazda Speed6 body, which has worked very well for me in the past on different cars, and is considered a very good carpet body to help lock in the rear end more.

Thanks for the help, actually I implemented most of the suggestions, the car become much easier to drive and the track roll problem disappeared. (and not last but not least I moved ahead on rank list:)

The winter season will finish this weekend than we move to asphalt also with foam tyres. I also would like to ask your opinion, what general setup you would suggest on asphalt with foam tyres(40/45 fr, 40sh rear), or what changes you would suggest versus the basic setup.

Thanks