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Anti-Roll / Sway Bars


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#1 Ratkiller

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Posted 26 February 2013 - 11:19 PM

I looking to do more track days with my 62 MK1and want to get to most/best handeling possible. I've notice Mini Spears sells two different types of anti-roll bars and I know KAD makes an adjustable verison as well. I'm interested to know what do most road racers use? Are they custom built or a standartd bolt on version I can purchase on-line?
What would you recommend?

#2 monster_mini

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Posted 27 February 2013 - 07:28 AM

In my opinion, anti roll bars/ sway bars are a dark magic, and I think way too many people just fit them thinking they're a bolt on instant performance item! Depends massively on how you drive your mini too! If you like toe out on the back and enjoy it twitchy but turning in like a demon, (aslong as you can handle it) I'd start with a rear bar on its own, and keep adjusting it until you feel happy:)! But there's so many other factors too...

Can you tell us abit more about the rest of the suspension? Is it all standard:)? Adjustable? Soft suspension cones ect?

And I think we'd all love to see a picture of this little beauty!

Cheers

Nick

#3 Ratkiller

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Posted 27 February 2013 - 05:25 PM

I'll get some pictures up soon.

Currently the suspension is setup for reliable but fun daily driving. I have red road/race springs with lowered GAZ adjustable shocks on all for corners with 10inch original Minilites. The front has heavy duty adjustable tie rods and 1.5¡ negative camber bottom arms, with 7.5 disc brakes. No camber kit on the rear. I usually run the adjustable shocks at 20 clicks on the front and 18 on the rear for around town driving. For the track day I tighten them up to 30/30. I have about 2 inch clearance between the top of the rear tires and the body. I saw a video of me on the track during a long off camber left corner and the rear tire was rubbing. So I'm planning to put on rear bumpstops, for safety reasons, but I'm thinking at least a rear swaybar would help with the body roll.

I'm leaning toward the adjustable KAD version. What do you think?

Edited by Ratkiller, 27 February 2013 - 05:26 PM.


#4 jaydee

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Posted 27 February 2013 - 09:15 PM

I've seen people fitting them in the paddock and removing them after a session, they told me the anti-roll bars cant cope with the un-even road surface, that was at mugello raceway a couple of years ago
So really try them on track first, then see if they're suitable for road use but i think not..

#5 monster_mini

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Posted 01 March 2013 - 12:45 AM

Sounds good:) I think a sway bar will help abit, but as the guy above said, not sure what it'd be like on the road.There's not pot holes on a race track! It's weird your getting that much body roll if these springs are road/race, it'd be interesting to see what the spring rate is like in comparison to the minispares red or yellow dot rubber cones. Bump stops sound good to look after your tyre / arch, however just be carefull if its always hitting them as if you turn it hard and it just goes solid, could get side ways pretty quickly!

From what you've said it sounds like a cool little set up you have going!

I'd recommend getting adjustable bottom arms, and you'll need some longer track rod ends just to be safe, then adjust the front suspension to whatever you wish. If it was just used on a track, I'd go for 2 degrees negative camber(what tyres do you use by the way?:) 4 degrees castor, and toe out is up to you, some people like it just a tiny bit, others like a whole degree. (Can't give all my secrets away;)

Rear is where you can make some big improvements, first of all I wouldn't recommend getting those brackets which have cerated plates and can do camber and toe, because they're just useless if I'm honest! Work out how much rear camber you have and then using abit of maths (trigonometry) you'll be able to work out how much to move it by to get some rear camber- again anywhere between 0 and -2 is what I've seen, have a play and see what you think! With rear toe, if your competent, I'd definitely make sure she's toeing dead straight!(remembering to toe it straight to where the front wheels are, not necessarily the car since not many minis are actually straight haha:p And see how you go from there!

And last but not least, don't forget race cars are low for a reason!:) so go as low as you are happy with!:)

Any more questions or if you don't understand anything I've said above(never been a good teacher!) let me know:)

Cheers

Nick

#6 Kat7Racing

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Posted 01 March 2013 - 09:49 AM

Anti roll bars are for the track, If you fit one just make sure you can disconnect it for road going and hook it back up for track days

#7 Ratkiller

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Posted 01 March 2013 - 10:17 PM

Thanks for all the input.
My springs, I'm not sure about the spring rate, but they are the red ones from MiniSpares. They list firm, but no other specs.
For the tires I was running the Yoko A032r's on 10x4.5 minilites. They held up pretty well but did have a bit of roll to them, an extra 1 inch ware mark on the outside of the fronts. I may try a set of HOTDs Hoosiers next time around, I've heard they have a much stronger sidewall.

Here's a link to a pic of me going through one of the lefts. This particular corner was a little banked.
http://www.gotbluemi...es/image26.html
Here's a pic of me leaving the same corner.
http://www.gotbluemi...es/image30.html
This one is during a parade lap. This is how it sits with no additional load on the suspension. The rear probably sits with a little less then a 2inch gap.
http://www.gotbluemi...es/image26.html

Edited by Ratkiller, 01 March 2013 - 10:29 PM.


#8 monster_mini

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Posted 03 March 2013 - 08:10 AM

Awesome pics!! Well if you can afford it, I'd definitely recommend fitting some yellow spot cones for the track, it will transform the car due to just stiffening it all up! Also the next easy way to make it handle better is make it wider, but I'm guessing you want to keep it looking like that!:)



#9 Ratkiller

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Posted 07 March 2013 - 11:07 PM

Yea I want to keep it looking like that, so no flares. Any thoughts on the green race springs vs. yellow spot cones?

I found a good article that explains the use of swaybars.


"This is a subject I should never get started on; I will try to give you the short story!"

For any of you that don’t know I have been racing Mini Coopers for over 30 years. And on this subject of I have some very definite experience. Before my later years in Road Racing I was national Autocross champion in a 1966 Hydrolastic Mini Cooper “S”. And while I have not road raced a classic Mini on anything other than 10” tires, my last couple of years racing the new MINI Cooper on BIG tires does apply to the classic with 13”.

At the very basics of this issue is ‘Balance’ and ‘Compromise’! The Compromise was started by the manufacturer when he decided to make a road car as safe as possible. All road cars are designed to have understeer (push or plow). It generally considered that if an inexperienced driver is going to get into trouble it will occur when he goes too fast into a turn, and rather than have the rear end snap around, the car is designed to push. In our front wheel drive cars that was not hard to achieve; with all the real weight and driving force on the front tires, it is easy to exceed their ability to grip.

The second part of the compromise is the manufacturer’s goal to make a car that handles well but is also comfortable to drive. If their intent was to sell cars only to road racers the results would be totally different. A car with very stiff suspension and very low roll center, such as a go-cart, will handle very well up to a point but would be terrible as a street machine; ‘compromise = comfort + handling’! In the very early days it was just a matter of making the car stiffer with something like Koni shocks set on ultra hard. We soon learned that we could go much quicker by controlling body roll while allowing the suspension to actually work. The purpose of a suspension system is to keep the tires in contact with the road surface under all conditions and body roll was the factor that affected it most. Sway bars are designed to control body roll and transfer energy from the body to the suspension.

While ‘Compromise’ continues to be a big issue with the application of sway bars to a Mini Cooper, ‘Balance’ also now becomes a key word. The use of sway bars allows you to control the roll center while maintaining a soft enough suspension to allow the suspension to work while still allowing the car to be driven on the street.

The principle behind a sway bar is to achieve a ‘balance’ to the car front to rear such that when we turn at our chosen speed we can maintain control of the car. As a Mini Cooper will naturally understeer in order to get closer to a balance, we either have to decrease the understeer OR INCREASE oversteer. In the true sense of the equation we can only decrease understeer (independent from affecting the rear) by increasing the tire grip on the front tires by using wider or stickier tires. Once you have done all you can to minimize understeer at the front, you need to compromise the overall handling in order to achieve the desired balance. This is done by inducing oversteer in the rear by the addition of a sway bar. The key here is to understand that a rear bar does not decrease understeer but rather it increases oversteer in an attempt to get to the balance point!

It is at this point that we need to also talk about other compromises in the equation: Driver skill, driver technique and typical use of the car. A driver with little or no experience should have a car that basically understeers. As his experience and skill increases, he will be able to control and enjoy a more balanced car. All of us have seen drivers go around sweeping turns with the car going back and forth from under- to oversteer and back to under, etc. This car is said to be perfectly balanced, right on the edge. The driver’s skill is now what gets the car around the fastest. But put another driver in the car and he proclaims it handles like a pig! This is where technique comes into play: some drivers insist on seeing how far into a turn he can drive before applying the brake, while others slow down and accelerate thoughout the turn. This is an entire subject on its own with hundreds of book written on it. My only point here is to have everyone understand that what is the perfect set-up for one car and driver is not necessary the same for the next.

All this just to talk about sway bars on the Mini Cooper. I would suggest that for perhaps 95% of people the use of a rear sway is the best and only option. I would NEVER attempt to drive a Mini Cooper in any kind of performance way without a rear bar. In fact, I recommend it for anybody that asks, even for 100% street application. A rear bar in a Mini Cooper, along with the proper shock and ride height set-up, can achieve what I think is the best way to go fast in the Mini and that is with ‘trailing throttle oversteer’. This experience is like none other in cornering. When done right you can drive the car VERY hard into a turn almost to the point of losing grip on the front tires (understeer) only to find that if you lift you foot off the throttle quickly that the load transfers to the front resulting in less traction at the rear and a ‘tendency’ for oversteer! This increase of load on the front tires then allows them to grip more and you find yourself again able to apply power to accelerate through the turn. Remember a tire has only so much grip, and you can use it up in either turning or accelerating. The stiffer the rear bar the sooner this transfer will occur.

It is almost impossible to put enough rear bar into the Mini Cooper to get it to actually oversteer- not that you can’t get the back to come around, but this is more due to technique than set-up. Remember how all the old rally guys would toss the Mini in one direction only to get the rear end to slide in the opposite direction!

Now comes the question; when do you use or need a front sway bar. Remember I talked about a rear bar is all that is needed with a proper shock/spring ride height setup is achieved; well a front bar is used to again compromise! As body roll has been identified as the major contributor to handling if the car has less than optimum spring/shock and/or ride height, then a front bar is helpful. Most Minis on 13” tires have a higher roll center than those of us on 10”; most drivers want to drive their car on the street in addition to racing of some sort; both of these require compromise. One of the modern issues with the classic Mini has been the recent introduction of coil springs to replace the stock rubber cones. When you cut through all the hype you find that the justification for the change is not improved handling but improved ride comfort. The car just feels better, and doesn’t pitch as much in daily driving. But guess what; here is that terrible word ‘compromise’! In technical terms you can install a spring set that is ‘stiffer’ than any stock runner cone. But these springs will feel softer on the street – because you have more body roll! In order to achieve a better feel the spring design has compromised on body roll.

All this said, a front sway bar is most commonly used when springs have replaced the rubber cones. Does this mean the springs are bad? No, it’s just a compromise that we choose to make and we need to understand the end results. With the springs and a front and rear bar you can actually find it easier to achieve the best of both worlds: handling and comfort. But when setting up a Mini Cooper with that many variables you also need to include the driver’s experience and skill as yet another variable. Remember that corning (ignoring the impact of the driver) requires the application of the entire suspension system, not just sway bars!

PS- call me anytime on the phone and I will be more than willing to actually give you the long version of this story!

And a few links that might be helpful: http://www.minimania...h_Inventory.cfm

And another review yields the following options to reduce understeer:

#10 monster_mini

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Posted 08 March 2013 - 03:30 AM

Cool article!:) one of many different view points:)

Put up a link to these green springs:)?

#11 Artful Dodger

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Posted 08 March 2013 - 08:12 AM

When you lower a mini to race height (as low as she goes!) you move the roll centre. This gives you crap handling

You can alter this by fitting bottom ball joint spacers. Endaf Owens of Owens fabrications (the demon miglia driver) is making them now for 40-50 pound a set

Talk to him and see what he thinks. It could make the handling MUCH better

#12 monster_mini

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Posted 08 March 2013 - 08:52 AM

Lol that's abit over the top mate, when you lower a mini to the ground like every race car that has ever hit the track, it doesn't instantly give it crap handling:p!

It's just one of the negatives of going low, but there are many positives,

Endaf has just found a clever way of making the gains by going low, but retaining the camber gain and correcting the roll centre issue!:)

Also depends on how low this guy is going to go! If you took a car you drive on the road anywhere near what you do a race mini on track, you'd bottom it out and be stuck on a large stone in the road!:P

#13 Cooperman

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Posted 08 March 2013 - 03:57 PM

Let's not confuse road and track Minis here. They are, and should be, very different in terms of road-holding, handling and overall performance.
Set a road car at standard ride height with dampers not too stiff, correct camber and caster and a bit of toe-in on the rear. However, set a racing car up low, with zero toe-in on the rear, an anti-roll bar to enable the power to be kept full-on right through the corner after correct entry and setting up under braking.
But, if you try to drive a race set-up Mini on the road, it will be slower than a road car and if you are trying to go quickly through a corner and have to lift off because the corner suddenly tightens, don't be surprised if you crash!
Look at the way rally cars are set up. They are standard height, or slightly raised for forest work, with supple damping, slight neg camber on the front and zero to about 0.5 degs negative on the back. They don't have an anti-roll bar, but they are the quickest Mini you'll ever find on normal roads.

#14 Ratkiller

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Posted 08 March 2013 - 06:28 PM

Red
http://www.minispare...mance.aspx|Back to shop

Green
http://www.minispare...mance.aspx|Back to shop

#15 rally515

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Posted 08 March 2013 - 06:32 PM

Red
http://www.minispare...mance.aspx|Back to shop

Green
http://www.minispare...mance.aspx|Back to shop


I'd go black from minitastic as there stiffness is more appropriate for road use & there cheaper:
http://www.minitasti.../suspension.htm

Edited by rally515, 08 March 2013 - 06:32 PM.





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