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Cornering Optimizing your suspension system.

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  #1  
Old 12-14-2006, 02:49 AM
JuniorMint JuniorMint is offline
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Default Alignment Numbers?

So I am about to install my new Ireland fixed camber plates and Ireland rear control arms. My car already has pretty serious suspension mods including PSS9's, I use the car for "spirited" street driving and it has never seen a track. What number should I tell the shop to aim for in terms of camber, mainly in the rear.
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Old 12-17-2006, 12:01 AM
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first off this thread should be in cornering... but it's all good, just givin you a hard time

your car is starting to look pretty race ready. throw it down to -3.5 and take it to the track already, yo!

or if you're trying to get your tires to last and you aren't gonna put the hammer down on the track for a bit stay cool and put it at -1.75 to -2.0 and called it a day. you can always flip it down to a more aggressive camber later
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Old 12-17-2006, 12:05 AM
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Hahah easy, Glenn! He's got a Cooper, which transfers less weight, and therefore produces less body roll, so less camber is required to achieve the same results.

Here's what I would suggest, for an aggressive street and occasional track car:

Front: -1.8 degrees camber, 1/16" toe-out.
Rear: -1.5 degrees camber, 1/16" toe-in.

This adds negative camber up front, but slightly reduces the rear camber setting, to help you rotate the car a little more readily. If you want a little more stability in your setup, opt for the stock setting of -1.75 degrees of camber in the rear.

BTW, you do have an adjustable swaybar, right? If so, what diameter?
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Old 12-17-2006, 12:20 AM
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sorry, still coming down from yesterday's adrenaline rush
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Old 12-17-2006, 03:03 AM
JuniorMint JuniorMint is offline
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Originally Posted by iDiaz View Post
Hahah easy, Glenn! He's got a Cooper, which transfers less weight, and therefore produces less body roll, so less camber is required to achieve the same results.

Here's what I would suggest, for an aggressive street and occasional track car:

Front: -1.8 degrees camber, 1/16" toe-out.
Rear: -1.5 degrees camber, 1/16" toe-in.

This adds negative camber up front, but slightly reduces the rear camber setting, to help you rotate the car a little more readily. If you want a little more stability in your setup, opt for the stock setting of -1.75 degrees of camber in the rear.

BTW, you do have an adjustable swaybar, right? If so, what diameter?

I have an adjustable 25.5mm rear sway, I have it in the middle right now and will probably crank it to stiff was everything is aligned
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Old 12-18-2006, 09:34 PM
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25.5mm is pretty fat! What sway is that?
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Old 12-18-2006, 09:59 PM
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25.5mm is pretty fat! What sway is that?
H-Sport Competition
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Old 12-20-2006, 03:09 PM
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Don't run any car or truck toed out! Zero toe or slightly toed in Front & rear is best. Toe out is not a good idea unless your running on speedway ovals, then you would only toe out the front left.
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Old 12-20-2006, 03:14 PM
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Don't run any car or truck toed out!
Sounds like the voice of experience, but mind sharing a bit more on why that is?

I have seen a 1/16" toe OUT in the front recommended by several sources in the MINI autocross world (and this is by some very competitively ranked drivers).
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Old 12-20-2006, 07:43 PM
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Sure Dave,
In all forums of racing misinformation is more prevalent then good information. How do you think those "top drivers" keep there edge over you?
Telling you pure bull on setup is a real easy way!
They are not going to give you what took them many hours of testing & tires to learn.
Tire manufacturers want to sell you more & more tires so you think they really want to help you figure out a good alignment setup?

The easiest way to understand the the benefits & necessity of toe in for stability is to take a look at another fun sport, snow skiing.

For you non-skiers ask a skiing buddy how beginners are first taught to point there skis, wedged inward much like toe in on cars. This wedge inward allows smooth skiing with great directional control.

Now what happens when you toe out your skis, loss of control & probably a crash!
With car alignment toe out makes a car real darty while driving in a straight line & even dartyer under hard braking.

When you toe out a car, your dragging & scuffing the outside tire sideways which is like walking with a club foot.
As a result of toe out you will experience bad tire wear, poor handling, dartyness, more rolling resistance in the straights & tons more resistance in mid turn.

I can go on & on about why you should not toe a car out, but Ive probable bored you to tears already.
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Old 12-20-2006, 07:48 PM
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That was very informative and eyeopening Bob.......I appreciate that!
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  #12  
Old 12-20-2006, 08:05 PM
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Yeah thanks
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Old 12-20-2006, 10:37 PM
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Makes sense
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Old 12-24-2006, 07:35 AM
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I agree, and warned about the dartiness under braking, but as with any aggressive set-up, it's a trade-off. Running a very slight toe-out up front forces the inside tire to scrub harder under sharp cornering, creating a rotational moment on the vehicle and allowing you to carve some very tight turns at speeds that would ordinarily cause you to understeer. The reason for the slight toe-in on the rear is to compensate for the dartiness under braking, and the sharpened response on the freeway. Yes, the car will respond more sharply, and almost to the point of dartiness under braking, but the rear end will stay planted due to the toe-in.

Adding 1/16" of toe-out is very slight, and should give you a slight handling advantage without the negative consequences you've described above. I'm running 1/8" out up front, and I have not experienced much in the way of poor tire wear, dartiness, or instability, as I'm also running 1/8" toe-in on the rear.

It's up to you, though. Zero toe up front is better than toe-in!

BTW, Junior, a little fair warning: An H-Sport competition rear swaybar is too stiff for a Cooper, and setting it to full stiff will magnify any instability in your setup or lack of smoothness in your driving style. I would advise you to go to a smaller swaybar, or at the very minimum, keep that bar on the softest setting, or be prepared for a butt-puckering surprise when you least expect it. If you plan on keeping it, definitely no more than zero toe up front, and at least 1/16" toe-in on the rear.
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Old 12-24-2006, 01:16 PM
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The forces of wheel rotation & steering arms stretch & deflect slightly as speeds increase growing your toe out condition. (the older the steering & suspension components the more they stretch)
When you set up toe in at 1/16 sitting on the alignment rack, the car will be near zero toe at 60 mph, because of these forces at play.

So your static 1/8 toe out is way toed out at speed, could really be 3/16 or more!
If you really want your car slightly toed out, start at zero & you will have about the 1/8 toe out your looking for when motoring at speed.
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