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AERO TUNING FOR FORZA MOTORSPORT

“For the super noob tuner, refer to the diagram below. This is the essence of how to tune your aero bits in a nutshell:

MORE DOWNFORCE

THE GOOD: Better cornering speeds, better grip, and ease of handling.

THE BAD: More aerodynamic drag, slower straight line speed, and reduced suspension travel in the bump direction. As speed increases, the springs compress, and the suspension gets bogged down.

For those of you that are noobs in the world of downforce, the basics go like this:

LESS DOWNFORCE

THE GOOD: More straight line speed.

THE BAD: More aerodynamic lift, slower cornering speeds (less cornering grip), car is more difficult to handle.

So how much is the right amount? For the most part, an increase in drag and reduction of top end speed is a good trade off for increased cornering grip as it will usually result in faster laps.

Here’s a quote on the subject from a great article I read:

“Although drag reduces top speed somewhat, the increase in cornering speeds makes for faster lap times, so some drag is acceptable….The key is to produce just enough downforce to maximize the average speed around the track. Produce too much downforce and the increased drag will slow the car excessively, too little downforce will hurt cornering speeds. It usually takes some experimenting with wing settings and other components to find the sweet spot where performance is optimized”.

http://www.modified.com/tech/0610sccp_automotive_aerodynamics_part_2/index.html

BALANCING OVERSTEER AND UNDERSTEER WITH AERO BITS

Adding the ‘Forza Front Bumper’ will generate downforce, which loads the front tires and adds front wheel grip, reduces understeer, and makes the car turn in better which keeps it from washing out in mid-corner.
Technically, the Forza front aero bit is a splitter. But semantics aside, the important thing to know is that it adds grip at the front.

Adding the ‘Forza Rear Wing’ adds downforce at the rear of the car, which loads the rear tires, increases rear grip, and reduces oversteer.

INITIAL SETTINGS – Should I just max out the downforce?

I think this is one of those questions that’s hard to answer, kind of like trying to define what’s the right amount of pepper to add to your eggs.

It's situational, of course, based off of driver preference and track type. If you were to ask me where to start, an intelligent reply would be keep both the splitter and wing dead in the middle and begin testing. Why? Well you can't use your aero bits to balance the car if both are maxed out, or both are set to the minimum. If your default settings are in the middle, you can tune around that, and have the luxury of using them as a balancing tool. So if the rear wing has a range of 100 to 200, set it to 150 and get out and test. Don't worry so much about initial settings, since you've got a long way to go with your tune.

I don't really do FWD, so I'll deal with RWD and AWD. RWD is situational and based off the characteristics of the car. In general, if you put a gun to my head and asked me for a black and white answer, my personal preference is I like to max out the front wing on any car, because I'm a firm believer in initial turn-in. If the front tires hook up and you can get into the corner, good things will follow. The other thing is most often the Forza wing is only giving you 100lbs of downforce anyway. This is a preference and philosophy, by no means a hard and fast rule. Friends of mine make me look ridiculous and put two seconds a lap on me with my own tunes with the aero turned all the way down. The amount of aero you run has a lot to do with how talented you are. I'm marginally talented, so I like downforce. Here's a quote:

“An Indy tech told me that the difference between a competitive Indy driver and a great Indy driver was the amount of downforce that was required to get the car to handle. The better driver could live with less downforce and drive their way through the handling demands.”

http://jimsgarage.wordpress.com/2007/08/18/aerodynamics-downforce-ground-effects/

In regard to AWD, you're dealing with understeer most likely, so again, I'm probably maxing out the front splitter. If the AWD car is front engine, you may want to rely on aero even more so, because you probably don't want to run too soft a front sway bar with the engine weight up front. If the front bar is too soft, you end up with too much body roll and the purpose of softening the front bar to cancel out the understeer is essentially negated.

In regard to the rear wing, if the car is RWD, front engine and is loose, you're probably gonna need it. If it's AWD, get the car to turn in to dial out the understeer, and tweak the rear wing as you test. I keep defaulting to the 'it's situational' line because it is. There's over 400 cars in the game, and track specifity plays a role as well.

SOMETHING TO NOTE ABOUT OVERSTEER AND UNDERSTEER

When we’re dealing with oversteer and understeer, we’re generally plagued by understeer on corner entry and oversteer on corner exit. The problem with sacrificing corner entry turn in (by reducing front aero) to fix corner exit oversteer is the notion that a car that pushes into the corner is more likely to be loose on exit. This is due to the increased steering angle required to get the nose to point in when you’re off throttle and the front tires aren’t hooking up. Remember that the more steering angle you have, the less grip is available for on-throttle acceleration out of the hole. You want to have the minimal steering angle you can get away with when re-applying power on corner exit. So make sure you get the nose of the car into the corner.

TRACK SPECIFITY

The last bit of info I’ll add about tuning aero is that the amount of wing you run will also be contingent upon the track you’re driving on. On momentum tracks like Suzuka, Mugello and Maple Valley that have a minimal amount of heavy braking zones and fast corners/sweepers, you’ll generally need as much aerodynamic grip as you can get on both ends. On ‘point and shoot’ tracks with heavy braking and tight corners like Road America and Sebring, carrying momentum into the corners isn’t as much an issue. In addition, both tracks have one thing in common, very long straights. The increase in drag due to maxed out aero will be more noticeable.

In summation, the initial quote applies. At the end of the day, fastest average lap time is all that matters. I hate to be the one to say it but ‘you gotta play around with it’ a bit to find the right amount of downforce for each situation.