Thursday, 2 April 2015

Guide To Setting Up Your Chassis


It's always been a difficult and time-consuming process to set up a chassis but I believe it should be as fun as actually drifting.

I have seen many people asking others online for their setups but that problem with that is driving style. You'll be very lucky if you come across someone else who drives similarly or even the same as you, and so their chassis is setup for their driving style.


What you should be using to setup is a set of guidelines highlighting the steps to take and in what order. There isn't really anything available online for this until a little while ago, those angels from Soul RC bought us these "commandments" from one of the top drifters in Japan.

(Image source: Soul RC Facebook)

These guidelines was bought to us during one of Soul RC's waffle hour live Q&A. You can find the original video HERE (@11:00) but I have a shortened video below. Just so you know, the shortened version is still 13 minutes long and isn't great quality but you just have to listen rather than watch. If you don't want to watch the video, read on..

(Video from YouTube by Soul RC)

Remember the rule from my geometry posts? Only ever change one thing, trial it and then make further changes. Changing too much at a time will disguise which change worked and which change didn't. So, here is my iteration:

Before making ANY CHANGES, set the EPA for the throttle (CH2) to 100%. Then go ahead and check your

0.  Final Drive Ratio
Although many have different opinions on this, I found a Yokomo tech sheet a while back and on it, it said to set your FDR to motor size. So for example, my 10.5T motor should have a 6.5 FDR, a 13.5T should be 6, a 15.T should be 5.5 etc. However, going by what Mitto said about moving off without wheelspin, I have now set my FDR to just over 7 and it works beautifully.

1. Front Springs
I've found that springs are one of the hardest components to tune. Once I realised that I should tune for "steering feeling", I found it loads easier. Use the stock spring, fit it so it has no play on the damper and try it. Adjust it, try it, adjust it, try it.. No good? Try a different set of springs. I will do one lap around the track not drifting and then one drifting and get a "feel" for the steering.

2. Rear Springs
These are being tuned for traction. Again, try it with the stock spring and adjust it and try it etc. What we are looking for here is a lateral push. As you pull the throttle back, the back of the chassis should retain it's angle while pushing forwards. Too much grip and you get a spin, too little and you get straightening up or vice-versa.

3. Front Damper Angle (upper position)
I always set my damper angle as far inwards as possible; the closest hole to the center of the chassis that I can use. This is because I like minimal grip up front to "force" counter-steer, I then tune the rear of the chassis so match the front. Essentially, the further in the the dampers are, the less grip you'll get. Start with the least amount and work your way out is my tip.

4. Rear Damper Angle (upper position)
Similar to the front angles except you are trying to balance the front. The same rule applies regarding damper angle; further in = less traction, further upright = more traction. You should position the rear dampers so that they are working with the front dampers. Again, set to factory and then adjust. What you may find is that after tuning, the front dampers are more upright and the rears are all the way in. Every chassis is different and if that is required to get your chassis handling right, don't be afraid to stick with it.

5. Rear Lower Arm Damper Position
6. Front Lower Arm Damper Position
These will control the roll speed of the chassis and is very much dependent on your driving. If your driving is very aggressive and you find yourself "snapping" in a direction change, you'll want these positioned further out. This will give you quick weight shift from one side to the other. The other end of that spectrum is all the way in giving you a more stable and predictable direction change which is better if you're starting out or on a large track.

The rear will control the roll of the entire chassis and the front will control roll when on lock. Run the track a few times and get a feel of how much lock you're using on average and tune to that angle. It's pointless tuning on full lock as CS chassis' rarely drift as such but would be more beneficial for RWD chassis' but that's a whole different game.

7. Rear Squat/Dive Control
This is the area I am working with currently. Let's say for example your chassis reduces speed quickly when you let off the throttle. By lifting the rear toe block on the rear suspension arms, you can add some "roll on". This is where the chassis will steadily decrease speed rather than slow down quickly as if you have drag brake on (ESC settings below). The other end of the spectrum is too much roll on. You can decrease that by lifting the front toe block instead, again at the rear of the chassis.

8. Front Anti-Dive
Similar to the rear of the chassis, the front suspension arms toe blocks can also be used to tackle adverse handling issues. Anti-dive is used to reduce understeer or "push-understeer" when on throttle. This is when the steered wheels lose grip and the chassis "tramlines" or doesn't steer as into the direction that you want it to go. By lifting the front toe block, you can decrease the understeer and gain back some of the grip. Hopefully you've set your front springs correctly in step 1 so you won't need to do much here.

9. Rear Roll Center
This is a difficult one to explain as it's based on imaginary lines created by the suspension arms, which join at a point in the centre of the chassis indicating the roll centre. But as soon as you put any force on the chassis whether its up and down movement of the chassis (pitch) or side to side (roll), everything changes. Ideally, if you can manage to figure out your roll centre, a drift chassis will benefit from a low roll centre at the rear and a high one at the front but it is all down to preference and driving style. HERE's some more reading for you but be warned, it is some next level sh*t! I would've put roll centre after..

10. Ackerman/Toe Setting
This, I feel, is also in the wrong place; I would've put these settings after lower damper positions. I have written posts on geometry previously so go ahead and take a look at toe (introduction) and Ackerman (advanced) and how they affect handling.

- ESC & Controller Settings
ESCs and controllers differ vastly and it is very difficult to identify and explain every different type. As mentioned in the video, your steering and throttle exponential should be set to linear eventually but you can apply some exponential to the throttle to train your trigger finger.

Some ESCs come with a "drift" setting, you're best off applying that to begin with and then learning what all the different functions are and what they do. I will do a post on my ESC, the different settings and what they all do once I've figured it out, until then, leave the punch and drag brake off and leave the rest as factory.

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This is a lot to take in and it can take a long time applying it but instead of copying someone else's setup, use it as a foundation. If you can't find sometimes else's or want to learn for yourself (which is the best way), set your chassis to the factory settings and work from there using these guidelines and what you'll end up with is a chassis setup for your driving style which can now grow as you grow.

So, remember, no matter which step you're working on, make sure you only consider that step and it's desired outcome and enjoy doing it whilst learning!