Tuesday, June 30, 2015

Drift Bible - Chassis Set Up for GCRC Raceway 2015 - Countersteer

If you come to GCRC there are some changes you might need to do to your chassis to get the best results.


Knowing every track is different, At GCRC you WILL be chasing grip. Drift and slide is not an issue.
The target is to keep driving speeds low and realistic on the diorama circuit.

GCRC Track Design and Surface

GCRC has a polished concrete surface.

It is very very smooth and you can run your body shell extremely low.
Even with 1-2mm ground clearance.

The layout is at the tighter end of the spectrum and requires a decent amount of control for the narrower layout.

The lack of a long straight means lower top speeds 

Although the track is surrounded by fleximble barriers, due to the lower top speeds, impacts are not a real issue.

in the past couple of years, I have had no breakages from impact. 

GCRC Control Tyre  

Control Tyre is mandatory for a CS or 50:50 chassis are the following :

RC-Art Derive RT-01SH ( HDPE Plastic tyre for Carpet )
Top Line Sports Edition TDT-002PE  ( HDPE Plastic for Carpet.)

Available in store at GCRC.

Acceptable others are similar such as RC926 HDPE and Kazama Premium HDPE

You will not have a problem sliding with these tyres. But you will need to try to increase the mechanical grip of a standard chassis.

Tyre wear is negligible.  I have some sets lasting 6 months or more.

GCRC Power Recommendations  

With the tyre grip at a minimum and the surface so smooth, it doesn't take much power to get the rear wheels spinning.

Most guys run a 17.5T motor which is more than enough with a CS setting.

Even a 21.5T

If you run a 13.5T you will end up reducing the full throttle EPA to about 70%

Honestly, Less power means more on throttle grip and not doing burnouts and wasting power.

I have tried to run a 7.5T on full throttle, it just sits there spinning everything. So it usually ends up on about 28%EPA. In other words, back to a 17.5T.

ESC temps will be very low and 5800mah batteries tend to last from 1 hour to 2 hours.

Suspension and chassis balance

Remember you will be chasing grip and reducing slip. So the softest settings and well placed weight make a big difference at GCRC,

I use light oils in the 20weight range and springs are in the softest ultra-soft range at the rear and slightly heavier oil up front but still with a super-soft range.

I also need a front bumper weight or weighted front bumper to get the front grip I need to prevent understeer.
Sometimes to counter this I use a very rear weighted bodyshell to give me slide control and length to my drift entries.

Front weighted chassis like MST MS01D also perform very well here.

Light plastic chassis also find traction difficult. So a bit of weight like a larger battery can make a big difference.

GCRC Counter-Steer Ratio.

What makes realism possible at GCRC is the ability to run higher CS ratios.

The low speeds and low grip mean that you can run a higher ratio.

What do I mean by higher ratio:

Well most high manufacturers don't make parts that increase countersteer over 2.0

This is fine for those starting out but the rear wheel speeds become higher at GCRC which isn't really desirable.

We like to under drive the front to achieve at least the same ratio and then slightly increase rear drive.

Target range is 2.5:1 ~ 3.2:1   (My personal favourite is about 2.8cs)

A setup like this is in belt drive is front 42t:10t  Rear 17t:33t

With low power motor and high counter steer, you can still squeeze that throttle!

Having said that, there's nothing wrong with a lower setting like 1.9, Just make the front softer so it will kick out the rear and be prepared to trickle on the throttle so as not to overpower the grip.  

GCRC Counter Steer Setting Summary

Surface: Polished Concrete
Control Tyre: HDPE for carpet
Power: Low rev motors around 17.5T
Suspension : Very Soft
Weight : Heavier and Slightly forward.

With those things in place your chassis dynamic will allow for ripping it up at GCRC

Enjoy your RC. 

Especially at GCRC!

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