Contour Enthusiasts Group Archives Forums Branches E. Great Lakes Getting rid of aussie bar and...

So I take it no one here knows the answer to my question then?

I guess I was not as clear as I wanted to be, when looking at a graph of a tires traction abilities, traction falls of extremely rapidly after it hits its optimal traction point, which is a little bit of slippage.

The stock svt places a huge amount of stress on the front tires, and under track conditions, the tires snow plow, which gives them drastically lower traction, that is why in many cases when people are out on track events, they feel they are going faster when they are going slower, and when they are going slower they are actually going faster, because when drivers are working harder they very often overwhelm the traction abilities of their tires on quick transitions.

As i said before, under track conditions the rear never skids, so therefore it has traction to give up, by keeping the front tires out of the "snow plow range", it is actually GIVING them traction.

Here is a good article I found on sway bars in grass roots motorsports. Yes they may have good information, but ford engineers have to tune their cars conservatively. Again, my car only shows oversteer during transitions, wich they indentify as being perfectly acceptable.



The Effect of Anti-Roll Bars Upon TLLTD
Ideally, you now understand how an anti-roll bar can be used to limit body roll, and you understand that reduced body roll can lead to a reduction in adverse camber changes for better tire traction. But what may not be obvious is the effect of anti-roll bar changes upon TLLTD (understeer and oversteer.)
In fact, given the above information, one might even assume that a firmer anti-roll bar, which leads to better camber control, would lead to better traction. If we add a firmer anti-roll bar to the front, traction loss diminishes, so understeer is reduced, right?
Wrong. Let's evaluate more closely the meaning of TLLTD-tire lateral load transfer distribution. Stated another way, we might describe TLLTD as the relative demand of side-to-side energy control that is placed upon the tires. Because a firmer anti-roll bar allows less deflection, it will transfer side-to-side energy (lateral loads) at a faster rate.
As the rate of lateral load transfer increases, additional demands are placed upon the tire. So if we install a firmer anti-roll bar in the front, then we increase the distribution of lateral load transfer toward the front tires. This increases the front TLLTD value, which will result in additional understeer, holding all else constant.
The same logic also holds true in the rear. A firmer anti-roll bar in the rear will increase the rate of lateral load transfer, placing more demand upon the rear tires, accelerating lateral traction loss and creating more oversteer, holding all else constant.
This is why blindly adding parts to your car may not produce the desired results. A wise consumer consults with-and buys from-knowledgeable experts that have the tools to make informed tuning recommendations.



I Want a 50 Percent TLLTD On My Car, Right?
Since on paper a 50-percent TLLTD indicates a balanced chassis, many enthusiasts are tempted to jump to the conclusion that this is therefore desirable. They may think that all cars should obviously come this way from the factory. Unfortunately, this is not the case-and the considerations are not that simple.
In reality, a car with a 50-percent TLLTD is literally on the constant brink of oversteer. And there are many factors that can quickly and easily take the car from the brink into a full-scale, out-of-control, spinning-in-circles disaster.
For starters, consider the effects of weather conditions that might create a wet or icy road surface. Or imagine that the driver happens to apply too much brake late into a turn-a common mistake among novice drivers. Or consider the effects of varying tire temperatures, tire pressures, or tire wear-all of which will have major impacts upon lateral traction thresholds. And of course, varying weight distribution, as a result of changing fuel tank levels, passengers, or the number of subwoofers in the trunk, will also impact TLLTD.
LOOK: With all of these things to consider, automotive design engineers are forced to create a more conservative TLLTD. As a result, they intentionally target higher front TLLTD values so that stock vehicles will be prone to understeer-the assumption being that understeer is safer and more predictable for the average driver.
For example, a stock DOHC Saturn is tuned to produce a front TLLTD of approximately 63.4 percent-a relatively conservative target. (But give Saturn some credit, as this is on the aggressive end of the conservative spectrum, especially compared to other front-wheel-drive economy cars.)
As a general rule, an average street-driving enthusiast is probably willing to accept some compromises-within reason-of a more aggressive TLLTD in exchange for better handling. A suitable target is probably a front TLLTD value of approximately 58 percent, a value that is considered aggressive, but suitable for street driving.

Rara Please explain this then...

When i lived in KC me and a friend had STOCK E0 SVT's.. His had a aussie bar. I could get my car on 3 wheels all day. The rear pass tire would come off the ground i have video of it. Me driving his car same speed all 4 tires where planted.. Kinda wondering how your losing grip if 2 tires are on the ground instead of 1..

I think its all fine that your a engineer or whatever at Ford.. But i think that the Aussie bar is a great upgrade for handleing.. if you want me to prove you wrong we can take 2 cars to a autox one with the other without and ill drive both in a blind comparasion. I have Auto-X'd both setups and the Aussie bar is much better than the stock.

They where Identically the same car with 2K difference in miles both stock suspenion. Stock radio everything, STOCK as stock can be.. both with the GREAT BF's...

And i Ran within .1 seconds 10 run's in a row in my car and every run in the Car with the Aussie i ran .5 seconds faster every Time 5 runs... SO if you wanna talk about consistancy. I don't know anything more consistant

Rara if you read the article, it says clearly that for safety reasons oem engineers use too much TLLTD,

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automotive design engineers are forced to create a more conservative TLLTD. As a result, they intentionally target higher front TLLTD values so that stock vehicles will be prone to understeer-the assumption being that understeer is safer and more predictable for the average driver.

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Yes, there is such thing as too much bar, but the article clearly mentions the fact that transferring TLLTD to the rear can be a very good thing.

As I have been repeating, the stock contour has too much front TLLTD and places too much stress on them, forcing them to work at overwhelming, traction killing slip angles.

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As the rate of lateral load transfer increases, additional demands are placed upon the tire.

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Plus, the part of the article you quited is discussing the effects of too much bar, the sentences that preceed that are talking about the negative effects of having too much understeer and too much front bar. Remember everything is proportion.

but what you are doing in the rear doesn't change the front, it changes the rear, you are simply rebalancing the car differently by decreasing rear grip.

As far as OEM's and how the cars are balanced, yes, they do tend heavily toward understeer; the Contour SVT however, is tuned far closer to nuetral than most FWD cars. A stock contour SVT will most definately oversteer under lift-throttle, or even trail braking if it is being driven to its limit (ask my Grand Am Cup crew chief how he knows this . . .) a stiffer rear bar simply makes this condition worse (depending on how you look at it) There are times, such as an autoX car, were it makes a lot of sense to force the car to be able to rotate faster at lower speeds, where this bar would be quite useful, but for higher speed tracks, or even on the street, it makes real limit driving a white knuckle experience.

Ask any real road course driver how they feel about a car that oversteers badly under braking.