One last thing worth mentioning since you want to Autocross - check with the administrating bodies in your area about the legality and class rules regarding the modification of your rear sway bar. Some classes do not allow this mod and you could wind up in Prepared class with some very experienced and competitive drivers/cars and wind up getting your **** handed to you and not have any fun.

If you just run time-only events, then good for you... but be mindful of class rules if you want to run anything else.

 

To second what billzcat1 said and to add my own 2cents, I installed the H-Sport Competition rear sway bar (a 25.5mm hollow bar, which is roughly equivalent to the 22mm solid bars in stiffness) and although it transformed the handling, at its stiffest setting you do need to be more attentive at high-speed. I usually had the bar on my MCS 03 (non-DSC btw) on the middle setting although one day I decided to test out the stiffest setting. While having a decent amount of fun on a twisty highway-on-ramp (not WOT, but with good use of the fun-pedal) I had to lift off abruptly to avoid an unforseen object on the roadway and the rear rotated around about four or five feet (thank goodness it was a wide ramp!) While I was able to correct the oversteer, I now respect the sway bar much more at speed and save the stiffest setting for the occasional autocross for which the stiffest setting is just brilliant. Maybe if I had DSC the fishtailing wouldn't have happened at all however even w/o DSC I've never regretted my decision to go with the stiffer bar.

 

Here is some sway bar comparison information that I had gathered and posted in a different thread. I did some investigating/comparing and came up with the following thoughts/observations:

- Alta's published numbers are increases over a 17mm bar (R53 Sport/JCW) not the R53 stock 16mm bar. Thus Alta's numbers are not comparable to Hotchkis numbers (which I believe reference to a 16mm bar).
- Alta's published numbers are 100% higher than I would state. I think of a 100% increase to be twice as stiff as the reference bar but Alta would consider it 200% (which makes sense from a multiplication sense).
- I would think of Alta's numbers as:
19mm solid bar: 15%, 40%, 77% not their 115%, 140%, 177%.
22mm solid bar: 113%, 160%, 229% not their 213%, 260%, 329%.
- If Alta's rates were combared to a 16mm bar they would be about:
19mm solid bar: 21%, 57%, 110% (estimated to compare to Hotchkis).
22mm solid bar: 164%, 232%, 333% (estimated to cmopare to Hotchkis).
- MiniMadness published numbers are calculated the same as Alta's which I think are 100% over stated.
- I believe that the MiniMadness numbers are referenced to stock 16mm.
- MinMadness numbers are:
22mm solid bar: 128%, 197%, 284% not thier 228%, 297%, 384%.
- The Alta and MiniMadness 22mm bars appear to be the same.
- I called H&R and they do not provide numbers for their bars.
- H&R 19mm bar is solid with two adjustment holes.
- Hotchkis published numbers are referenced to the stock 16mm bar (not the R53 sport/JCW 17mm bar).
- Hotchkis website states the 19mm bar as tubular but based on the published numbers, I believe it must be a solid bar.
- Hotchkis numbers are:
19mm solid bar: 54%, 88%, 128% (at least I think this bar is solid).
25.5mm hollow bar: 226%, 294%, 383%.
25.4mm solid bar: 314%, 394%, 501% (1" solid bar).
- The Whiteline and MiniMania 20mm solid bars appear to be the same.
- I could not find data on the Whiteline or MiniMania 20mm bar.
- I could not obtain any data on the Rspeed 22mm solid bar.
- A 22 hollow bar, with normal 2.75mm wall thinkness, is equivalent to a 20mm solid bar.
- A 25.5 hollow bar, with normal 3.1875mm wall thinkness, is equivalent to a 23mm solid bar (actually a little stiffer than a 23mm bar).

 

You couldn't get an R53 with the 16 mm bar - that size was only found on the Cooper (R50). And not even all of the Coopers had the 16 mm bar - you could get them with a 17 mm bar as part of the SS+ suspension package.

 

Thanks for the clarification on the 16mm vs 17mm on various models.
I am still guessing that the MiniMadness numbers are compared to a 16mm bar because their numbers seem to high to be capared to a 17mm bar.

 

If you're talking about Minimadness' 22mm bar (+128%, +197%, +284%), those are in the ballpark when referenced to a 17mm bar.

Assuming similar materials and geometry, bar stiffness varies with the 4th power of the bar ratio. For example, going from 17mm to 22mm is (22/17) ^ 4, or 2.80. This means that the stiffness of the 22mm bar will be 2.8 times that of the 17mm bar, which is an increase of 180%.

180% is pretty close to the quoted stiffness of the Minimadness bar in the middle position, so I'm fairly certain they're referencing it against a 17mm bar.

If they had referenced it against a 16mm bar, the ratio would have been (22/16) ^ 4, or 3.57. This would be a 257% increase over the 16mm bar.

But you're absolutely right that most of the manufacturers are incorrectly stating their bars' stiffness. When Alta says "115%, 140%, 177%", that's really only an *increase* of 15%, 40% and 77% compared to the stock bar. I think it's just a basic misunderstanding of the math involved. While 75 is 300% of 25, it's only a 200% *increase*.

 

I still think that the Mini-Madness 22mm bar is referenced to a 16mm bar. The Mini-Madness webpage even shows a "stock" 16mm bar in the picture as a comparison to their 22mm bar.
The Mini-Madness 22mm posted rates actually match very well with an increase over 16mm (calculated 257%) and their posted increase of 284% for the stiffest hole. I guess it all depends on how the holes (lever arm distance) line up with the stock holes.

Maybe someone can measure the lever arm distance to the various holes on a Alta and Madness 22mm bar. That would help us figure out the different ratings.

The lever arm distance on the 17mm bar is about 170mm (that is from the center line of the endlink hole to a point even with the edge of the straight part of the bar (by straight part of the bar I mean the portion where the bushings mount to the vehicle). I measured to the inside edge (closest to the endlink) of the straight portion of the bar. Measusing to the center of the bar would add half the thickness of the bar or about a 178mm lever arm.

 

I contacted George at Mini-Madness, he said that the Mini-Madness 22mm rate increase numbers are referenced to a stock 16mm bar. But now I am not sure about that.

From the pictures on the Mini-Madness site, I made crude measurements of the 22mm bar hole positions compared to the hole position of 16mm bar shown in the same picture. It appears that the hole on the 16mm bar is about in-between the middle and softest hole on the 22mm bar.

Thus, this would make me believe, as stated by ScottRiqui, that the Mini-Madness bar rate increase numbers are really referenced from a 17mm bar.

I am totally confused.

 

I had my Alta 19mm installed today on my R50 and I'm as happy as a pig in $#it. The car is much more flat/stable/neutral when I dive into off ramps, or make quick turns. Much less pushing in the front, although I haven't explored the limits yet.

After we took the stock 16mm bar out, I laid it on the bench next to the Alta. The Alta is noticeably stouter than the stocker, and the stocker's one hole lines up with the Alta's middle hole. We installed the new bar on the firm hole. I can always back it off if it was too much, but it seems to be perfect the way it is.

When installing it, we hollowed out the rubber bushings enough to allow a wrapping of a teflon strip inside the bushing and around the bar, and then put copper grease around the bar where the teflon grabs the bar. We left the rubber in place at the inside, away from the bar's collars, so that the teflon doesn't slide out. No squeaks. Very nice.

And it's very cool to look through the rear wheel and see the red bar. =o)

 

Might as well just get the 22. What is 3mm? seriously.

 

Small differences in bar diameter make a big difference in stiffness because all else being equal, (materials used, location of mounting holes, etcetera), the stiffness of one bar compared to another depends on the ratio of their thicknesses *raised to the fourth power*.

So, a 22mm bar is almost twice as stiff as a 19mm bar. (1.8 times stiffer, actually, since the ratio is (22mm/19mm), which you then raise to the fourth power.)

 

Sure, but you (and I'm speaking in generality) can do anything and everything to your Mini Cooper, but someone with high performance driving training will whomp on you with bicycle wheels and a bad spark plug. The point is, 22 or 19, you can adapter to the difference in driving, they are just as good as one another. Might as well go big or go home

 

Actually, the point is to set the car up as good as you can or want to get it, and not go overboard to the point of causing a negative. Maybe you can 'adapter,' but why not have the car behave the way you want it to with less effort on your part?

 

idk if its been said.. but when thinking about sway bars.. the idea for changing suspension to alter handling characteristics is to always try to add grip to acheive this, not take it away. you might consider that if your car is stock

 

big difference really, also you have to look into what kind of bar your getting. as there are many different choices for each bar, you need to decide if the bar is the right thickness for you flexible enough exc. I still dont recommend a sway bar for the first mod to induce oversteer

 

I doubt 22 is 'overboard', maybe if it were 30-40, yes. The point being, it's all in your head. If I strapped a rocket engine to your Mini, after a long time of driving it, the rocket will start feeling slow, and you'll want to strap another rocket to it. Good drivers adapt to the vehicle's setup. If you want an easy to drive car in the curvies, keep the car stock. BMW over-engineered this thing! As for me, I bought my Mini for fuel economy back when gas prices were $4.80/gallon. If I wanted a fast car I would've kept my BMW M3 or Mercedes CLK AMG. It's just funny to me how big of a deal someone can make about a simple sway bar, air filter or muffler. lol

 

your right, fast drivers can adapt to cars. but I have to dissagree on your sentiment here. we are talking about making the car itself faster. just because the car becomes more difficult to drive does not mean its by any means faster. usually that means completely the opposite. the car may feel faster because the limits of the car have been dramatically altered for better or for worse, my guess is worse if you are driving the car the same and you think you are going faster cause the rear kicks out. granted, for a good driver its nice for the car to rotate but theres better ways than just a sway bar. also a good driver can adapt to alittle understeer and will favor this if its allowing him to go faster than using another kind of krutch for a better feeling.

 

It's the same for any vehicle being set up for any high performance environment. You want balance. If a too-thicker sway bar is going to make the rear end come around, whereas stock the front is going to plow, neither alternative achieves a balance, if you are talking about making the car move as effieciently as possible through a given road course/exit ramp/twisty backroad. There is a point for every vehicle where more is simply too much.

The 'might as well go big or go home' mentality reminds me off all the guys I know that thought putting super in their pintos and vegas was actually going to do some good. Yes, it may have made their cars microscopically faster because their wallets were being excessively and unnecessarily lightened. Power-to-weight ratio, ya know! =oD

 

In my opinion I wouldn't change out the rear swaybar unless you change the front and the rear at the same time.

 

Uhm, not necessarily! The reason is it depends on what you are trying to change in terms of the handling of the car. A rear bar upgrade will allow the car to pivot better in hard cornering, reduces understeer, and makes the car far more fun to drive.

If a larger front bar is also added, the car will tend back to understeer, but be slightly flatter in the same corner.

In the pushing 7 years of MINI rear sway bar sales, I have sold HUNDREDS and HUNDREDS of rears (might be more than a thousand even) I have sold maybe 5 front bars. Mostly to harder core track guys.

Hope that helps! Thanks for asking!

 

Some information on our 19mm bar:

Calculations made based on bar material being constant

Stock Diameter New Diameter % Increase
Swaybar % increase based on diameter alone 17 19 156

OEM 17mm BAR SETTING #1
EFFECTIVE RATE 117 LBS/IN

ALTA 19mm BAR SETTING #1 RATE INCREASE OVER STOCK 115%
EFFECTIVE RATE 135 LBS/IN

ALTA 19mm BAR SETTING #2 RATE INCREASE OVER STOCK 140%
EFFECTIVE RATE 165 LBS/IN

ALTA 19mm BAR SETTING #3 RATE INCREASE OVER STOCK 177%
EFFECTIVE RATE 208 LBS/IN

ALTA 22mm BAR SETTING #1 RATE INCREASE OVER STOCK 213%
EFFECTIVE RATE 250 LBS/IN

ALTA 22mm BAR SETTING #2 RATE INCREASE OVER STOCK 260%
EFFECTIVE RATE 305 LBS/IN

ALTA 22mm BAR SETTING #3 RATE INCREASE OVER STOCK 329%
EFFECTIVE RATE 386 LBS/IN

 

Same info now for the 22mm bar:

Calculations made based on bar material being constant
Stock Diameter New Diameter % Increase
Swaybar % increase based on diameter alone 17 22 280

OEM 17mm BAR SETTING #1
EFFECTIVE RATE 117 LBS/IN

ALTA 22mm BAR SETTING #1 RATE INCREASE OVER STOCK 213%
EFFECTIVE RATE 250 LBS/IN

ALTA 22mm BAR SETTING #2 RATE INCREASE OVER STOCK 260%
EFFECTIVE RATE 305 LBS/IN

ALTA 22mm BAR SETTING #3 RATE INCREASE OVER STOCK 329%
EFFECTIVE RATE 386 LBS/IN

ALTA 19mm BAR SETTING #1 RATE INCREASE OVER STOCK 115%
EFFECTIVE RATE 135 LBS/IN

ALTA 19mm BAR SETTING #2 RATE INCREASE OVER STOCK 140%
EFFECTIVE RATE 165 LBS/IN

ALTA 19mm BAR SETTING #3 RATE INCREASE OVER STOCK 177%
EFFECTIVE RATE 208 LBS/IN

 

I agree

like I said, using a sway bar in this situation to only reduce understeer is simply not technically reducing understeer but increasing oversteer. you are just reducing rear grip. like someone above said its about balance. I can understand people wanting this in our cars as they understeer quite a bit. however it is much better to add front grip to increase oversteer than to take it away. A sway bar is not a bad thing if used correctly. the sway bar is great in terms of fine tuning though.

ps. if you are going to use a sway bar as one of your only suspension mods, I would go with less, as less as possible. altas 19% on the softest setting sounds almost perfect if you do decide to go this route.

thanks for the info adam :tu:

 

For those that want to use their MC or MCS for street driving with a bit better handling.

Then no need to change the front bar (more labor too).

You can upgrade the rear bar to three hole adjustable 19mm bar since it gives three settings that are fully usable depending on what you want to do. Start with the softest setting.

Now it might be true that if you choose a very stiff rear sway bar that also changing the front sway bar can make some sense in terms of upgrading both ends AND use fully adjustable bars to get exactly what you want- but that isn't really necessary for street use MINIs.

 

white line generic bar chart

http://www.whiteline.com.au/docs/bulletins/010barup.pdf

running 20mm on mid setting