MouserueV2's forum posts

Avatar image for mouseruev2
#1 Posted by MouserueV2 (5 posts) -

@keris said:

You had it right until that part. No, no, no! The engine will sit behind the driver, not the car. Damn near most high performance exotic cars (not to mention open-wheel racers *choo, choo* and Le Mans prototypes) are mid-engine. The engine sits in between the two wheel axles giving the car a much better front-rear weight distribution. When the weight of the engine is put towards the center of the car, the center of gravity is closer to the axis of rotation and the car's moment of inertia is reduced. This gives the advantage of making it easier and quicker to turn. Rear-engine cars are notoriously prone to oversteer. Porsche has only been able mitigate the effects on their own RR cars through their continual suspension tuning.

You're right, thank you for correcting me. I was oversimplifying my example for informational purposes, probably to a fault. I'm no gear head by any means, so my crass vocabulary regarding front/mid/rear-engine vehicles leaves something to be desired. I just enjoy the physics of it all. But, yes, a car with the engine in the trunk, literally over the rear axle, would likely handle horrendously. Luckily actual rear engine cars are hard to come by in Forza 4 (although there is the DeLorean, the only supercar as far as I'm concerned). The point, really, is that any kind of gross imbalances in the car at any point is going to lead to handling issues.

I think figuring out how to balance a car and how to prevent skidding while maintaining maximum speed is the only way to improve time. The things you describe are finer points to be perfected after the fact. There's no point in memorizing a course if you can't keep the ass end from swinging out every time you take a turn. Maintaining control is something you need to nail down first, especially if you're afraid to drive anything other than front engine, front wheel drive cars.

I agree with turning off auto-braking, and auto-steering. If you're not comfortable with braking distances and driving lines, it's ok to turn on the visual driving line for a time to get a feel for those things; just don't build all your skill off of relying on it because the ultimate goal is to be able to turn it off. Use it to learn what and where an apex is, and where to brake and accelerate around it.

I believe that stopping a car is damn near impossible without ABS and starting the faster cars without traction control also requires an enormous amount of skill. I'll let you and peer pressure determine whether you should have those on. Stability control, however, seems detrimental if you want to learn how to drive something other than a front engine, FWD car.

Late braking, like @keris was talking about, is also a fairly easy but important concept to grasp. The point is you want to spend as little time braking and as much time accelerating as possible while still keeping the car under control.

Now these physics-based, procedural ways of thinking about your driving may or may not work for you. If rote memorization is your thing, then turn off the driving line, run the time trials by yourself, and memorize courses and landmarks. Different strokes for different folks.

As a side note, that link to the GT2 manual is a phenomenal resource.

Avatar image for mouseruev2
#2 Edited by MouserueV2 (5 posts) -

The most helpful resource I've ever seen about how to play driving simulators is the instruction manual for Gran Turismo 1. In it, it basically says that the most important thing is distribution of static friction/grip on the tires. There three things you ask your tires to do that all eat up some of the limited static friction/grip of your tires - accelerate, decelerate, and turn. Once the grip is out, you skid and inherently lose efficiency (e.g. speed, braking power, turning radius.) because static friction is a stronger force than kinetic friction.

Of this very simple concept arises very complicated scenarios in a race. For example, when turning, you want to commit as much as your tires' grip/static friction to the turn. This means you cannot be accelerating or decelerating (or, rather, you should be applying very little acceleration to keep wind resistance and other types of friction from slowing your car). This is why it is often better to regain control by simply letting of the accelerator rather than hitting the brakes. Rather than committing your already-skidding tires toward trying to brake, letting off the accelerator allows your tires to regain static friction/grip. At that point, you can brake, assuming the regained traction isn't already enough to carry you through the turn.

Another thing to realize is that you can take advantage of the car's shifting weight when driving. Whenever possible, you want to put as much weight onto the working wheels as possible in order to increase grip/static friction. This is why nearly every high performance car uses the rear wheels to drive it forward. During acceleration, the car's weight shifts to the back, over the rear wheels, increasing grip and, therefore, acceleration. During braking your weight shifts over the front, turning wheels, increasing your ability to turn. However, since both accelerating and decelerating eat up your precious limited grip resource, you want to do your braking immediately before a turn. With the weight still shifted over the front wheels, you can stop braking and begin your turn with your increased grip.

This concept is why you're finding front wheel drive cars easier to drive. Most newer drivers brake too earlier and try to accelerate too much during a turn. Front wheel drive cars will always be subject to understeer because you are asking your two front tires to do both 100% of the accelerating and 100% of the turning. Furthermore, when accelerating, your weight will shift to the rear wheels, decreasing the amount of grip you can use to do your accelerating and turning. This is why front wheel drive cars are slow to accelerate and slow to turn, but also why they don't spin out.

Rear wheel drive is the preferred drivetrain in performance cars because you can put all four of your tires to work. While the rear wheels drive the car, the front wheels can turn the car. This is also where engine placement comes into play. In a front engine, rear wheel drive car, a majority of the weight is put over the front wheels, increasing turning grip, but decreasing driving grip. This explains front engine, rear wheel drive cars' propensity towards oversteer and spinouts.

You'll often see the engine sitting in the back of many supercars. This is to increase the grip under acceleration while decreasing the possibility of oversteer. Since the car's weight will want to shift backwards during acceleration anyway, also placing the engine in the back will ensure that as much of the engine's power as possible is shifted to the driving wheels, providing superior acceleration. While this also decreases grip among the turning wheels compared to front engine cars, the advantages of a rear engine, rear wheel drive car often outweigh the disadvantages in a high-speed racing situation since you want to do your braking and turning at different times to maximize the efficiency of the front tires to perform both actions.

So there you have it. You have three big players: 1) the car's shifting body weight when the car is in motion, 2) the engine location, and 3) drivetrain type. Knowing where all three of these factors are located relative to your car at any given moment is the key to better driving. This says nothing of aerodynamics and inertia, but you can probably figure that one out with the knowledge I've just given you. Notice how I also mentioned nothing of memorization of tracks, which I consider tedious and a more advanced driver skill. What I have provided is a relatively simple, procedural way of determining how to predict what your car will do at any given moment, which I consider far more important than knowing what the upcoming turn will be. That's why there's a minimap. Now go forth and conquer.

tl;dr, amirite?