The goal of the following article is to give an overview, as well as two interesting pictures, to the reader in regards to Formula 1 car setup - and a rough idea of the complexity that every team/driver has to cope with.
Note: Some of you may be more advanced in F1's technical matters, so to some extent you may be familiar with the information below. But I'm sure you'll like the pictures.
Probably quite often you hear from a driver after the race: "For some reason, we couldn't get the balance right with the current setup and I was struggling on every fast|slow corner".
Conventional racing wisdom says that the car setup is a balance between different things, but sometimes could be a trade-off, too, for example, if you want to overcome certain shortcomings of your design, e.g. running "more wing" to compensate for lack of downforce.
Let's dive into the details about on-track settings.
- Tires - A bit aside from tire optimal working temperatures, depending on the compound (90 - 125C), a word about the pressure. Usually, they (the tires) are filled with a special, nitrogen-rich air mixture, designed to minimise variations in tyre pressure with temperature. The mixture also retains the pressure longer than normal air would.
The tire manufacturer would provide the teams with a limits for variation, so it will be up to the race engineers to decide, because incorrect values may simply ruin the car's performance.
A typical average pressure number would be 19 psi.
- Suspension - There are couple of settings and terms I'd like to highlight:
Camber, caster, toe, rear and front ride height and rake.
- Camber - That's the angle between the vertical axis of the wheels and the vertical axis of the vehicle when viewed from the front. In a simple picture, that looks like this (negative camber):
Ferrari F150 - Negative Camber Tire setting
(click for larger image)
Photo credit: http://ferrari.com/
Negative camber merely means that both wheels are inclined inwards at the top, as seen above on Ferrari F150. If you are looking for a typical ballpark number, that would be for example 3 degrees, i.e. the wheels are inclined inwards by 3 degrees compared to the center line.
- Caster - That's the angle to which the steering pivot axis is tilted forward or rearward from vertical, as viewed from the side.
Just have a look at any shopping cart wheel to understand what this is.
As it can be seen from the final two images below, teams can use figures from 9 to 12 degrees, for example.
- Toe - If you look a car from above, a pair of wheel can have their leading edges pointed to each other - this is Toe-In, whereas opposite - edges away from each other, that's Toe-out. Again, let's use Mclaren 's 2012 competitor, MP4-27, to demonstrate this:
Mclaren MP4-27 (click for larger image)
Photo credit: http://www.mclaren.com/mp4-27
On the left, that's the axis showing Toe-In, only in case where both wheels are aligned the same direction (V like shape).
Similarly, the opposite is true for the right axis, which is Toe-Out. (Like Lambda ( λ ), from the Greek alphabet).
More details on what Toe setting can bring in the comment section of the post.
- Rake, ride height - Both are related, but put simply, rake is the car’s attitude from front to rear. Such setup should, in theory, increase the diffuser exit area, and thus increase rear downforce, for example, but it's not that simple, because there are number of settings to take into account, like suspension geometry, overall aero setup, induced oversteer from stiff rear suspension, etc.
Example or rake here (image link @ http://scarbsf1.wordpress.com Mclaren MP4-27).
In both pictures below you can see real numbers for rear and front ride height (in mm.)
- Engine maps/modes
- Map is rather a high-level term describing variations of fuel strategies, ignition timing, torque settings and so on, whereas mode (or mix) is more like a setting for being inline with race demands, like fuel saving and proper amount of power.
Examples of team communicating those are:
Red Bull telling Vettel: " torque map 5 "is available", while Mercedes say to MSC: "torque mode 3"
It won't be unusual to hear race engineer on the radio: "Engine 2, mix 5" on the start - they use those values to communicate with the driver the proper settings throughout the course of the race.Example of engine software modification was the infamous "Off-throttle blown diffuser" employed last year mainly by Renault-powered engine teams.
Small hint about how the things could be done here - software / automotive engineers will know the answer to that riddle.
- Gear ratios - While real numbers can be seen in Arrows A22 picture below, we should note that this setting can really make a difference. For example, back in 2011 season it was quite evident that Sebastian Vettel had shorter 7th gear choice for Monza - a move which had its merit, namely for better acceleration out of the corners. It was a bit of a gamble, too, because Vettel was assuming that he would lead right from the start and won't need to overtake anyone. His top speed was affected, too, but it played well for him in the end.
- Differential - Among one of the most important things that driver can control from the cockpit. An example of its importance is the end of the race, where the fuel levels are going down, and car starts to behave differently, so alterations are needed.
On average of 5 laps there is at least one adjustment, though sometimes drivers are doing it from one corner to another.
The settings are usually a numbers, just as Rosberg was advised to try "mid-corner diff 7 setting" in Valencia FP2.
- Angle of attack (AoA) - That's something pretty self-explanatory - it's related to the more or less extreme angles of a wing, for example, aimed to achieve respectively downforce or high-speed.
The efficiency of a wing is its downforce/drag ratio - more downforce (or lift) typically comes at the cost of more drag and lower top-speed. The greater the angle of attack, the more downforce and drag.
A while ago (2010), a mechanism for changing the angle of attack of the front wing was available for drivers, but in 2011 this was no longer allowed.
Illustrated nicely with the following image, F2012 front wing:
- More on aerodynamics is coming here, in the blog, as well as other places, in the next few months - not general aerospace, but Formula 1 related.
- Brake balance / bias - Often adjusted by the driver from the steering wheel. During the race, the brakes can worn to some extent, for example, and in order to avoid instability during braking, the pilot can switch the bias from rear to front or vice-versa. In some cases the brakes can experience extreme overheat (thermal runaway), being loaded with values between 400C and up to 1000C.
- Ballast - Usually plates from high density metal like tungsten steel. Often planted on places where balance and in particular weight in small available space is needed.
One piece of it usually fits on your palm, and could weight about 11 kg.
It's a setup sheet of Arrows A22 - a car that competed back in 2001.
|"Arrows A22" car setup 2001|
And here's a more recent one. Prior to joining back the F1 madness in 2012, Kimi R. had to complete a "smoke-test" with an old Renault car, namely R30.
|Renault R30 - Kimi in pre-2012 private test|
Photo credit: http://f1news.cz
These are real numbers from the notebook of his race engineer and that's part of the amount of data that goes into F1 car setup.
Finally, there's a picture available with a team race weekend program, Toro Rosso were generous enough not to hide the sheet from curious eyes. While it's not exactly a car setup, it still gives a good overview of how many of the described permutations are being tried on Friday alone. The picture is from Monza, 2012:
|Larger version available, image courtesy of http://f1.f-e-n.net|
Thanks for reading all the way down. These are some of the important pieces that take place in a Formula 1 car setup. I'd love to hear more from you, in case I missed something significant, or just a general feedback.