XRAY - Model racing cars

Hi all
I need your help in order to setup my T3 2012.

I will participate to a national race on this outdoor asphalt track of the south of France.



This track has a good general grip but tire’s wear is slightly important. Actually my main problem is overall grip and rear grip at corner exit (and other drivers don’t have this problem). I have to down my laptime by 0.5s.

Here is my setup after the last practice on this track :

General: 10.5T 0 timing GM motor / Tekin RS pro / FDR = 4.53 / Mazda speed 6 / Ride 36sh (official tires) / chassis 2mm

Front set up:
•Ride height 5mm
•Solid axle
•Track width 186mm
•Shock oil 350 / piston 1 hole / 3.2 spring
•Roll-center at middle position
•Antiroll bar 1.4mm
•Camber 1.5° / Caster 4°

Rear setup:
•Ride height 5mm
•Ball diff
•Track width 189mm
•Shock oil 350 / piston 1 hole / 2.8 spring
•Roll-center at middle position
•Antiroll bar 1.3mm
•Camber 2°


Next week, I will try :
•4 mm ride height (no bumps on the track)
•thinner antiroll bar (1.3mm front and 1.2mm rear)
•Higher rear roll center for quick direction changes, but I’m not sure that it will works due to my rear grip lack.

Thanks for your help

Why such stiff springs?

I've never tried a 3.2, but the few times I used a 3.0 I lost mid corner steering.

Also, why the 1 hole pistons, your shocks must be very stiff?

Hi,

i usualy drive on a big open asphalt track with large curve. So hard springs seemed to be the right choice.

But you're right, i should try smoother springs, may be 2.6 rear and 2.8 front. Did you ever try progressive springs ? May be it should be a good compromise.

For the shock piston, this is the best choice i have tried on the local track. But yes it's slightly stiff.

Regards

I had a set of the longer (T3'12) progressive springs, but don't recall using them outdoors.
If you have some try them on the front.
I would start with 2.8 & 2.6

Outdoors I almost always used to run HPI Silver front and rear

You should definitely try thinner anti-roll bars as you already suggested. The springs are also most likely too stiff. Which track width shims do you use at the rear? 189 is very wide for asphalt.

Hi,

thanks for answering.

I have tried thinner anti-roll bars and smoother springs : the car is definitely faster and easer . (I have won 1s per lap... )

So many thanks for thess advices..

For the rear track width , i use 1.9mm shims on the rear of the whisbone, and 0.4mm shims too on the front of the whisbone (189mm and 3° toe in). Is it too wide ? But with narrower width, will i lost rear grip ?

Regards.

Any particular reason why you are running the ball diff in the rear over the geardiff?

you would be instantly faster with geardiff and a hell of alot less maintenance..

I switched to a gear diff in back and the rear is better planted from the start. I never could seem to find the right setting for my ball diff.

Hi all,

I use ball diff because it's easier to adapt the diff setting to the changing grip track condition.

I tried both last week end during the race, and i was faster with the ball diff.

The car was just anwsome with your advice. I used 250 oil and 2.6/2.8 springs.

Thanks for all.

Regards