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Cornering Optimizing your suspension system.

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  #1  
Old 02-05-2006, 07:23 PM
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Default Front Sway or Front Strut Bar...

I know this has been covered in a couple of different threads but I need to come up with a plan for my car for the near future... If I can or have to do one, which should I do? I'm a worried about my ass getting away from me with the competition h-sport bar, so I want to do some kind of front mod to counter balance it. What do you guys think? I need to figure this part out before I get my other suspension mods put on.

I've heard that the front sway is probably the better route to go but at the same time I know people who have had front's and took them off cause they didn't like what they did. I can't seem to find much information on what upgrading the front sway will do anyway...

The strut bar (M7) has the benefits of possibly stopping some mushrooming and even though I've read the article Ivan postedhere I dont' know that I throughly understand it.

The sway bar is cheaper but the labor is far more expensive.
The strut bar is a little more expensive but I can install it myself.

Help me out guys. I wanna get my stuff put on but I gotta figure this out first.
-G
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Old 02-05-2006, 07:53 PM
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Quote:
Originally Posted by simplygriff
I'm a worried about my ass getting away from me with the competition h-sport bar, so I want to do some kind of front mod to counter balance it.
If you're concerned about the Comp bar, I would get a 19mm rear bar (h-sport/alta) and then sell your Competition bar and offset a good chunk of the cost of the 19mm bar. My basic strategy with this recommendation is to avoid throwing more money into the front sway (which is going to be more expensive from a parts perspective and more labor intensive), I would just address the fundimental issue, go to the sport rear bar, and offset some of the cost.

Then, you could to either the M7 strut tower brace or the strut tower plates (depending on which flavor you'd like you anti-mushrooming protection in).
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Old 02-05-2006, 09:28 PM
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front sways are strictly uesful for road racing. They are overkill for street applications. It's pretty much neagating the difference made by your aftermarket sway bar.

The strut brace really isnt necessary in terms of handling performance until you have a fully upgraded suspenion and are forcing it under heavy G's. But its nice that it stops mushrooming possibly.

the comparison is pretty apples and oranges though
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Old 02-06-2006, 03:07 PM
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I think I may need to rephrase my concern.... My finance manager/safety engineer (wife) has concerns that I'm gonna fly my ass off the side of a mountain at Dragon in May. I am slightly concerned with this too with the info I've gotten from my mechanic but I was just going to do the springs and rear sway and see how things were. My wife wants me to do things right and safely so she wants some kind of front something done to the car. That means a new part for me.

I'm kinda feeling the strut bar even though it's kinda unnecessary I like the idea that it could potentially stop the mushrooming and reduce what little body roll I would have if any.

I can't really find any info about what a front sway does though. Is it gonna make the front turn more in line with the back? Does it reduce the risk of the back end drifting out?

I feel like such a noob in the suspension dept. I really appreciate all the help you guys offer. Thanks much!
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Old 02-06-2006, 03:46 PM
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The strut brace will have little to no effect on body roll, its more to keep things in place under heavy load.

Since you have a rear 22mm bar what hole is it in ? A front bar ( sway ) will definitly effect over/understeer. I was told by a few people that the front bar makes little difference but I dis agree, I have the front h-sport and I put it on as one of the last mods I did to the suspension and it made a HUGE difference in how flat the car corners and how much oversteer/understeer is present. Its fairly cost prohibitive due to how much of a pita it is to install, you are looking at $400 + for the bar installed. The strut brace will give you some bling factor and should HELP with the mushrooming or preventing it.

To me the 19mm bar is limited and if you are agressive and are planning more in the futrure you will outgrow it. Firmest on the 19mm is slightly less than softest on the comp bar. ( at least that is what I remember hotchkis saying )

When I put my rear bar on most of the rest of the suspension was close to stock and I couldnt find anything negative related to the 22mm bar running on soft.

So...what setting is your rear bar on ?
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Old 02-06-2006, 04:16 PM
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Well... It's not on yet but I was planning on running it on soft to start until I saw how it handled. I was afraid of outgrowing the 19 bar. That's why I went ahead and picked up the 22. I don't like buying parts twice.

The cost is definately a factor right now too, but I need to something. You're pretty spot on with the extimate I got to add a front bar.

Do you have the comp. or sport on the front?
-G
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Old 02-06-2006, 04:58 PM
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The front swaybar, in theory, will reduce weight transfer and body roll and allow you to corner faster when used in conjunction with a stiffer rear swaybar. In practice, this isn't exactly the case. A swaybar basically serves to stiffen the outside suspension in a corner by borrowing spring force from the inside suspension. The outside suspension compresses, pushing the arm of the bar up, which twists the bar, forcing the inside suspension to compress. This works great for the front-end in a rear-wheel-drive car. In our FF beasts, this can create a lot of wheelspin by excessively lifting the inside front tire on corner exit. If you have a limited-slip differential, this can often negate that effect (so long as the tire doesn't completely lift off of the ground), but without the limited slip, expect wheelspin to increase substantially when you try to pull yourself out of a corner. The best way to compliment a stiffer competition rear swaybar would be to raise the front spring rates (reducing body roll and weight transfer without the inside-tire-lifting effect of a swaybar), but this is impractical for your application, as you're not running coilovers that would be able to accomodate custom racing springs.

That said, if you're really concerned about the back end stepping out, I would go for a milder swaybar than the H-Sport competition. You're really not going to see much of anything with regards to changing the cornering attitude of your car from a front strut tower brace with the rest of your setup, so until you raise the strength of the forces acting on those strut tower braces with other suspension modifications and R-compound tires, I wouldn't bother with it.

One thing that's nice about the Ireland rear swaybar that I use is that it has a huge range of adjustment, so you can make act very mildly or crank it up for oversteer, but if you don't like the noise produced by spherical bearings, it may not be the right option for you.
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Old 02-06-2006, 05:59 PM
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Quote:
Originally Posted by iDiaz
The front swaybar, in theory, will reduce weight transfer and body roll and allow you to corner faster when used in conjunction with a stiffer rear swaybar. In practice, this isn't exactly the case. A swaybar basically serves to stiffen the outside suspension in a corner by borrowing spring force from the inside suspension. The outside suspension compresses, pushing the arm of the bar up, which twists the bar, forcing the inside suspension to compress. This works great for the front-end in a rear-wheel-drive car. In our FF beasts, this can create a lot of wheelspin by excessively lifting the inside front tire on corner exit. If you have a limited-slip differential, this can often negate that effect (so long as the tire doesn't completely lift off of the ground), but without the limited slip, expect wheelspin to increase substantially when you try to pull yourself out of a corner. The best way to compliment a stiffer competition rear swaybar would be to raise the front spring rates (reducing body roll and weight transfer without the inside-tire-lifting effect of a swaybar), but this is impractical for your application, as you're not running coilovers that would be able to accomodate custom racing springs.

That said, if you're really concerned about the back end stepping out, I would go for a milder swaybar than the H-Sport competition. You're really not going to see much of anything with regards to changing the cornering attitude of your car from a front strut tower brace with the rest of your setup, so until you raise the strength of the forces acting on those strut tower braces with other suspension modifications and R-compound tires, I wouldn't bother with it.

One thing that's nice about the Ireland rear swaybar that I use is that it has a huge range of adjustment, so you can make act very mildly or crank it up for oversteer, but if you don't like the noise produced by spherical bearings, it may not be the right option for you.
I can agree that most of that is pretty much how it went down on my car. Definitly corners faster and flatter but there is aso the wheelspin on corner exit...at least there was before I added the quaiffe. I am thinking about swapping my front springs out and get somthing linear as opposed to the progressive ones that come with the pss9's my concern is how it will effect the valving and if it will be worth it or not. I am pretty damn happy with the car right now and after I get it all dialed back in alignment wise I think I am almost done....almost :-)
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Old 02-06-2006, 06:00 PM
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Alright so can someone give me an example of when I might lose my back end? Would it be simply taking a corner too fast? Steering in too hard? I know it's been said that "slalomability" will increase but may be more unstable. What else would cause the back to get loose?
-G
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Old 02-06-2006, 06:07 PM
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going into a turn too fast and giving too sharp a steering input...loop it
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Old 02-06-2006, 06:09 PM
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Quote:
Originally Posted by simplygriff
Alright so can someone give me an example of when I might lose my back end? Would it be simply taking a corner too fast? Steering in too hard? I know it's been said that "slalomability" will increase but may be more unstable. What else would cause the back to get loose?
-G
Anything that shifts weight forward would cause the back end to loosen up. Before I describe what those actions are though, remember that the stock MINI is set up with a good margin for understeer, so adding a mild swaybar may bring you closer to neutral without going into oversteer territory. On the other side of the coin, I was able to force my MINI to rotate when it was bone stock, so driver input can generally overcome the limitations of the way a car handles.
  • At the absolute cornering limit, lift the throttle. This shifts weight forward, causing the back end to lighten up, reducing grip in the rear. With aggressive swaybar settings, the rear will slide out. Neutral settings, all four will begin to slide (dorifto!). Understeering settings, the car will simply correct its line and tuck in tighter without sliding. The type 930 Porsche 911 (late-70's to late-80's) and even the type 993 (early- to mid-90's) were notorious for exhibiting snap oversteer tendencies on throttle lift, thanks to the weight of their engines hanging behind the rear axle, combined with neutral-to-oversteering suspension characteristics.
  • Yank the e-brake. Self-explanatory.
  • Trail-braking. This is a somewhat advanced maneuver employed by road racers wanting to force the car to tuck-in on corner entrance. Classical cornering style is where you get your braking done in a straight line before corner entrance, release the brake, then turn in. Trail-braking is where you begin your braking in a straight line, but as you release the brake, you proportionally begin to dial-in steering input, so for a brief moment, you're on the brakes and turning in. This small braking force pushes weight towards the front wheels, which also serves to lighten up the rear, causing the car to point its nose towards the apex. Some have done this accidentally, and wondered why their otherwise neutral or understeering car suddenly oversteered on them. Pay close attention to corner entrance and you can either avoid this or use it to your advantage, depending on your level of bravery. On a car that is already balanced towards neutral or oversteer, this technique can bring about a lot of oversteer or even a spin, so use it carefully!
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Old 02-06-2006, 06:11 PM
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lifting off the gas durring a turn

you should be more than fine with the 22mm on soft and 90% of the cars out there run a stock front bar
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Old 02-06-2006, 06:35 PM
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Thanks for the examples everyone. I've googled some of this stuff and found a bit too but it was a lot of formulas and not enough pictures.

So will a strut bar do anything at all for cornering? or is it pretty much just for looks and potential mushrooming?

If I have the money should I do the front sway? I think detlman said it makes the car corner flatter and faster. What do you mean flatter? Does it have less risk of breaking loose? Bottom line, my question is would it be safer to do the front or not? I'm thinking from a canyon carving point of mind.

Also if anyone has some good explanations of understeer/oversteer I'd love to read more on that. I have the jist of it but I want to further my knowledge.
-G
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Old 02-06-2006, 07:21 PM
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Quote:
Originally Posted by simplygriff
Thanks for the examples everyone. I've googled some of this stuff and found a bit too but it was a lot of formulas and not enough pictures.

So will a strut bar do anything at all for cornering? or is it pretty much just for looks and potential mushrooming?
With your current setup, no, not really. Put some R-compounds on there and it'll be a little more apparent.

Quote:
Originally Posted by simplygriff
If I have the money should I do the front sway?
No. Any gain you may get in faster corner entry will be negated when you step on the gas and your inside front tire goes up in smoke. Detlman has a limited slip!

Quote:
Originally Posted by simplygriff
I think detlman said it makes the car corner flatter and faster. What do you mean flatter?
Flatter = less body roll. Reducing body roll can help corner faster, but remember, suspension doesn't make the car go faster--YOU make the car go faster. Reducing body roll also makes it a little harder for a beginner to sense the impending limit of the car, especially with slightly more aggressive tires that make less or no noise.

Quote:
Originally Posted by simplygriff
Does it have less risk of breaking loose? Bottom line, my question is would it be safer to do the front or not? I'm thinking from a canyon carving point of mind.
Less risk of breaking loose? Not really. If you push it too hard, it's still going to break loose, just in a different way. Again, it's up to the driver to sense an impending skid and either back off or compensate once traction is lost. The car only does what you command it to do, swaybar or not! With that in mind, if safety is of paramount concern, take a driving class or attend an autocross so you can safely get a feel for where the limit of your car is, and how to correct it if you happen to overstep that limit.

Quote:
Originally Posted by simplygriff
Also if anyone has some good explanations of understeer/oversteer I'd love to read more on that. I have the jist of it but I want to further my knowledge.
-G
Understeer is when the front tires lose grip before the rears. It results in the front of your car plowing forward against the will of your steering wheel inputs, carving a wider line than you intended, or in the worst case, sliding forward in a straight line. If you encounter understeer, remember that adding more steering input won't do anything to correct it beyond a certain point, since the front tires have already lost grip, so your demands cannot physically be met. To correct it, lift the throttle to shift weight forward, and point the steering wheel according to where you want the car to go. Sometimes the front of the car will regain grip abruptly, and if you've cranked the wheel over quite a bit, be prepared to correct your line!

Oversteer is when the rear of the car loses grip before the front, resulting in the back end of your car swinging towards the outside of the turn, tightening your line. Extreme oversteer will result in a spin! In all cars, regardless of their engine/drivetrain configuration, you'll have to steer in the direction you want to go when your car enters an oversteering condition. Since the nose of the car is pointed towards the inside of the corner, you'll need to turn towards the outside of the corner to compensate, also known as "counter-steering". In a front-wheel-drive car, correcting oversteer is a bit counterintuitive, so it'll take some getting used to. To correct oversteer in an FF, dial-in a bit of counter-steering and the step on the gas! This will shift weight rearward, forcing the tires against the pavement and regaining grip. Again, this may happen abruptly, so be prepared to correct your steering inputs without overcorrecting, as this may cause your car to fishtail and eventually spin out.

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Last edited by iDiaz; 02-06-2006 at 07:29 PM.. Reason: Corrected "front tires lose grip before the fronts".
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Old 02-06-2006, 07:24 PM
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Oh, and BTW, one of the most important things you can do to prevent understeer and oversteer from occurring in the first place is to drive SMOOTHLY! Don't be jerky with your inputs and don't demand more from the car than it can handle. Enter corners slower than you expect your car can handle, then slowly and smoothly work your way up until you feel you've reached a comfortable limit. Entering the corner slower will generally result in faster exit speed (and faster speeds on the subsequent straightaway) anyway, so get used to it and you'll become a safer, faster driver.
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