XRAY - Model racing cars

Hi,

this weekend I attended the first outdoor race this season with my T3 2011.
The control tire changed this season from GM Sorex 36 to LRP 30X and most drivers were struggeling with little oversteering over the weekend.

I started with Martin Hudy's "Low traction - asphalt" Setup as our track was slippery due to dust and pollen and this is where I got to:
xform/index.php?act=view&ID=442&setup=t3_2011

My car was one of the fastest on track and I managed to win the race but I wasn't totaly happy with the car.
I had to drive very smooth and round as the car tends to break loose in the rear (offpower mid-corner and onpower corner exit).
The ammount of steering was good but I would like to have a more planted feeling in the rear.

Any ideas or suggestions what I could change on the car?

I'm planning on turning the servo like on Alexander Hagberg's car which should help me a bit with the smooth driving but this won't be enough.

Thanks for your advices!

Best regards
Dennis

P.S. Here is a picture to get you an idea how our track looks like (running anti-clockwise):

are you running a rear geardiff ?

I would suggest the following changes from that basic set-up to get more rear traction:

Front and rear shock oil 450 cst with zero rebound

Front kick-up +0.75mm

Downstop 5.5 front and 4.5 rear

Take out your 1mm shim for bumpsteer

Less front camber (-1.5 degrees)

Take out the front row of screws from the rear mounting of the top deck

Shim on top of the c-hub front, use 1.5mm

Shim on top of the rear hub, use 4mm

Thanks for your tips! I will try these changes this weekend on track.

I'm not running a geardiff as I wait for the Xray one to be released

But one question:
By using 5.5 downstop in front together with +0.75 Kick-Up the car will have more uptravel in front compared to 5 with horizontal front suspension, won't it?
Should i measure the downstop in front of the arm or a the back as it will stay nearly where it was before? Or was it your intention to give the car more uptravel in front?

The offset of the 30x tyres is slightly different to most others so we ended up using the narrow hexes (-.75) when we ran those tyres. You need to file the set screw hole on the rear hub slightly or it hits the wheel.

I am sure the kick-up will help even though this option will give slightly more uptravel. I measure the downstop from the front of the arm just where the kingpin enters the arm.

Hi,

yesterday I got a chance to try the Set-Up changes Alex suggested.
The car defenitely got more consistant. The rear only steped out once or twice in 7 minutes due to hitting bumps on our track or perhaps overdriving the car
In the end I was about 6 seconds faster on a 7 minutes run and pretty happy with that.

The changes I additionaly made were running a LTC-R (LW) and standing up the rear shocks to the box setting.

Alex, since the track temperature changes rather much throughout the day, what would you change on the car from the morning (15°C air temp.) to noon (26°C air temp.)?

Many thanks and I appriciate your help and Input.

I am glad that your set-up changes have worked well.

One typical change between morning and afternoon, due to increased track temperatures, is to use heavier shock oil since it will thin out a little in hot weather. For example if you use 450 shock oil in the morning you may want to use 500 or 550 in the afternoon. It will also help the tires to overheat less.