THE INSIDER’S GUIDE
Back in Episode 36 of the Insider’s Guide series, we investigated the basics of air flow in relation to slipstreaming and dirty air. This episode however, we’re looking at how you can vastly improve your aerodynamic efficiency through tuning ride heights and the all-important and frequently misunderstood rake angles.
This goes beyond simply adjusting wing angles, as with a lot of modern race cars, the majority of effective downforce is produced from the floor and diffuser of the car which ‘sucks’ the vehicle to the track. Getting the ride height and rake angle set up correctly for your car will see you achieving better downforce levels without producing too much drag from higher wing angles which will hinder top speed: this is known as improving your car’s aero efficiency.
One thing you will need to note though, right off the bat, is that each car is different. Even though you can apply the same methods and process for tuning, the actual values or settings you will want to use in individual cars’ setups is going to vary from car-to-car and track-to-track, even cars within the same class.
This takes time, with small incremental changes needed, but the rewards are huge if you can get this aspect of the car setup nailed.
Tuning For Higher Speeds
Tuning for reaching higher top speeds is relatively simple; you want to get the car as low as you can and as flat as you can when nearing the highest speed you’ll reach on the straights.
Getting the car low and flat will reduce its profile and the amount of drag it produces, allowing it to cut through the air easier. Generally, for this you will want the rear slightly higher than the front in the setup, and have the rear springs slightly softer to allow the rear of the car to sag down and become level as the air flows over the wings and bodywork.
Slamming it down to the ground on the lowest settings isn’t always necessarily the best way to go though. Having the car too low increases the chances of bottoming out which will prevent you from reaching top speed, and whilst you are reducing the amount of drag you’re producing, you’re also reducing the amount of downforce you produce.
Having the car a little higher than the absolute minimum can prevent the underside of the car from bottoming out, and can also provide a little more downforce to allow you to get through and out of a corner leading onto the straight quicker.
Don’t be afraid to raise the car 4-6mm higher than the minimum settings in order to find the best performance here.
Tuning For High Downforce
Tuning for high downforce is going in the opposite direction to tuning for top speeds. You will want to try and keep the front reasonably low as it gets more downforce, but the rear you will want to raise up to allow more air to flow through the diffuser.
You don’t want to raise the rear too high though, as air will ‘spill’ out the sides of the car before it reaches the diffuser, reducing its effectiveness.
Likewise, you don’t want the front too low either, otherwise you won’t get the amount of air needed under the floor which is needed to get to make the diffuser to work in the first place.
You’ll therefore need to find a balance that enough air is being fed to the diffuser without losing any spilling out from under the floor, and ensuring that you’re maintaining the car’s balance without too much aggressive rake.
Rake is the difference in angle between the underside or floor of the car, and the surface of the track. Having a shallow rake means that the angle of the floor is parallel, or close to, the surface of the track. An aggressive or high rake angle means either the front or rear of the car is lower than the opposite, and there is more of an angle difference between the floor and the track surface.
Positive rake is where the front of the car is lower than the rear, and negative rake is where the rear of the car is higher than the front.
In pretty much all modern race cars, you will want to lean towards positive rake. It is extremely rare to see negative rake angles. High Downforce cars will use more aggressive rake angles in order to maximise downforce, and cars that utilize ground effect will prefer a shallower rake angle. Experimenting through trial and error, and having some understanding of the type of car you’re driving and tuning, will be needed here.
So now you’re probably wondering how to go about adjusting the car setup for all this. Well these are the main parameters you’ll be using:
Ride Height – Pretty obvious, but this will allow you to adjust how high the car sits above the ground and the amount of rake the car has. The important thing to note with this though, is that the settings you put here are your Static Ride Height measurements, i.e., when the car isn’t moving. Once the car is in motion and the speeds increase, your ride heights will change as the car is pushed towards the surface of the track, so keep this in mind when tuning this setting.
Front & Rear Downforce – These are your wing and splitter angles that are attached to the bodywork of the car. Most people use these as the main method to tune downforce, but they should be more used as a secondary option for more fine tuning, with getting the ride height and utilizing the floor as the first option. Decreasing the values will lower the wing angles and produce less downforce and less drag, where-as increasing the values will increase the wing angles and produce more downforce and drag. The higher the wing angles, the greater force you will have pushing the car down towards the tarmac, and therefore the further your ride height will deviate from its static settings when at speed.
Spring & 3rd Spring Stiffness – These will allow you to control how much movement and fluctuation there will be in your car’s ride height. Softer springs will allow for more movement whereas stiffer springs will allow for less which is better for aerodynamic performance. The less the car is rolling and moving around, the better the various aero, floor and diffuser elements will perform. If your car has a 3rd Spring, this is also a good way of reducing unwanted movement without having too much of an impact on the car’s handling balance.
Bump Stop – The bump stops are another method of controlling how much the ride height will change. Having bigger bump stops will allow for less change as the car will start to rest on them at higher speeds when it is being pushed down by the air flow over the car. If your car has a 3rd Spring, then you will also have a 3rd Damper Bump Stop option to utilize here too.
When it comes to testing and tuning your ride heights, the Telemetry HUD view will allow you to monitor your ride heights in real time. This will indicate the actual ride height as you drive the car, allowing you to see how much it is changing as you drive around the circuit, and get an idea as to whether you’re getting the car level when at higher speeds.
Some tracks are smoother and therefore easier for testing the ride height. The Mojave Cougar Ridge circuit features a drag strip section which is perfectly flat, making it ideal for testing ride height and rake angles when driving at similar speeds to the circuit you’re creating your setup for.
When it comes to tuning downforce, this is where you will need to look outside of the game at 3rd party apps in order to get raw data.
You can if you wish do it based on feel and seeing what kind of speeds you’re able to carry through corners, but the PC2Tuner app for example [http://forum.projectcarsgame.com/showthread.php?62171-PC2Tuner-Engineering-Tune-Visualization] exposes telemetry data, one of them being your rough downforce levels being produced by at the front and rear of the car.
So there you have it, a huge secret that is known and used by few but when understanding and applied correctly, can provide some very powerful and efficient results. Watch Yorkie065 explain it all with this easy to follow video explanation in this week’s Insider’s Guide Episode.