Yearly Archives: 2011

No matter what car you drive, there are a number of suspension braces available to supposedly improve handling. People shell out hundreds, even thousands of dollars on strut bars, under body braces, suspension member braces, fender braces, and frankly braces that attach to just about anything that has a bolt in it.

But what do these bars really do, if anything? Are all braces the same or are there important differences between them?

In today's article, I hope to begin to decode a little bit about each of these extremely important questions. While everyone just assumes they wouldn't be so popular if they didn't "work", I am here to tell you that there are far more bad products on the market than good ones - especially when it comes to chassis braces.

I am going to limit my discussion here to strut braces as they are generally the most effective and common. However, aside from placement, all other braces you can fit to your car are going to have a similar function. (more…)

Most enthusiasts are aware that lowering a car's center of gravity is good for handling and indeed, grip.

It's easy to see the real world implications as well when we think about how a tall SUV handles versus a very low Ferrari or Corvette.

Where the Center of Gravity Is

The car's center of gravity has both a horizontal (x, y) and vertical (z) location and actually refers to a single point where if suspended, the car would balance perfectly (at least in theory).

So vertically, we already know that the lower the center of gravity - the better. What about horizontally? Well, again, take a look at super cars - the closer weight is to the center of the vehicle the better. This is why super cars are typically mid-engine, so the heaviest part of the car (the engine/transmission) is closer to the middle of the vehicle.

The center of gravity in most cars is roughly at the top of the front bumper in terms of height (just a very rough estimate). The (x,y) coordinate of the center of gravity is much more variable, the Y being affected by the car's front and rear weight distribution. So in most cases, the CoG is at bumper height, somewhere in front of the midline of the car as you look at it from the side of the car. As you look from the front of the car, it is going to be either in the driver or the passenger's lap as most cars are slightly heavier on one side or the other.

Improving Center of Gravity - Vertically

Lowering a car is one way to improve the vertical center of gravity. This will offer increased stability, lessen the risk of roll over in extreme situations, and in most cases increase lateral grip (or the "g" handling figures on the skid pad). There are practical limits on how low you can go due to road imperfections and so on. There are also limits on how low you can go on a factory suspension without actually hurting handling. Usually around an inch of lowering is the farthest you can go without serious changes to your suspension geometry... but more on that in another article.

Vertical CoG can be improved by removing weight or choosing not to locate weight high in the vehicle. You can also get a CoG advantage from choosing a vehicle without a sunroof. Sunroofs in modern cars are around 25-30lbs, but in older vehicles they were sometimes 40-60lbs. In any case, take note that BMW thought it worth the exceptional expense to use a carbon fiber roof on many of their M vehicles. A few pounds on the roof of a vehicle can make a significant difference on the track, and 10-15 lbs can make a noticeable difference even on mountain roads.Having removed the sunroof on a car before, I can say that removal is not ideal (reasonably expensive) and you'll be better off to start with a car without a sunroof if possible.

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A lot of car guys give the OEMs a pretty underwhelming amount of credit. However, I think what they fail to remember is that the original manufacturer, while concerned with many things we typically are not concerned too much with (noise/harshness/cost/etc), spends more money designing the heater knob in your car than most aftermarket part companies make in a decade. Seriously, they're that serious (especially the Japanese and Germans!)

In other words, despite there being some very clever tuners out there, the OEMs are usually FAR more clever (and better funded/resourced) than we give them credit for - and thus, in the right cars, they can be a great source of inspiration.

Older cars and slower cars can always look to newer and faster cars for great ideas. In this article, I'm going to show you how you can look to ingenious OEM designs to improve your own car.

See the brake duct?

Discovery

While working on Project Lexus, I was thinking about putting together an article on a cheap brake upgrade in the form of brake ducts. We'll probably do something on that in the future, but while doing a bit of research, I noticed that the IS300 actually already has brake ducts - and some rather clever ones at that!

They actually have implemented them in a way that many of you can replicate to reduce drag AND get some really effective brake cooling in the process. (more…)