So I live out here in Southern California, run with my local SCMM MINI club and I live with 1/2 mile of some of the best canyons out there, Tuna cyn, Decker cyn, Mulholland cyn...

Long story short been testing out the rear 25mm H-sport comp sway bar for the last 2-3 months and holy sh*t its a beast to handle.
A lot of guys in the club are running the 19mm or the 22mm, (all hollow) and I have personally driven all 3 bars...
The 25mm is night and day from the 22mm.

My MINI has all the go fast goodies, weight reduction, suspension etc.. and by far the 25mm is not for the faint of heart, been running it on the middle setting and let's say that its Tail Happy, tokyo drift status, ok maybe not that extreme but damn you got to be ready for the "slide" only lasts a millisecond till the font tires pull you through the turns..
Maybe you guys have had different experiences with the bar, I've tried gas levels too, full tank vs. 1/4 tank and so on and so on.
My final conclusion;
95% will go for the 19 or 22mm bar, the other 5% that are batsh*t crazy, Like me, you will enjoy the 25mm.
Turns the MINI into a monster to drive.

Not trying to "scare" anyone off here with my review, just my .2 cents on overall feel for the last 3 months with the 25mm comp bar. Hope this helps for someone deciding between 22 and 25mm.

Oh side note my car is set-up for canyons not track use.
Very tight and technical 2nd, 3rd gear turns.


Obviously not the fastest way through a turn, but damn its a rush.

Next up for testing dial the bar back to the low setting and got some fully adjustable SPC camber plates up front to install.Running a better tire will help too, the Sumitomo's are not the best, but good for the $$$.

Will follow up with a write up on my new set-up shortly.

 

From the other coast, I installed the H-sport comp 25.5mm bar over the winter and found it to be a great bar for auto-x. I run in the 'D' Stock class that allows this change within the SCCA rules.

My experience has been a little different. I usually run the softest setting on the street and full hard at an event, but sometimes I forget to change back and have the full hard on the street. Even in the rain I don't find the car all that tail happy.

The weirdest thing is turning right into driveways with steep aprons and having the car lift the inside rear wheel off the ground.

A note for the OP. If you add the adjustable camber plates you could be making your problems worse. By adding more camber you will be adding traction to the front end, increasing the traction imbalance between the front and rear and making the car even more tail happy.

Changing to a stickier tires will not change the balance, just move it to a higher level (think higher speed) when the rear end wants to race the front, which will make your canyon blasting riskier than it is now.

 

Interesting ok 1st question
Do you have lower control adjustable aka lateral links?

Rear seats in or out?
Hardtop or sunroof?
05 or 06?

Just running some theories, so your saying take it down a notch on the bar and should be way different?

What you were saying about rear wheel lift, another guy who runs in our club out here has the same problem stock 04 jcw suspension, with koni fsd's and everything else stock...

 

You are lucky to live near those canyon roads. I try to drive them anytime I go south for a meeting.

I had the 25.5 Hollow on my 2003 MCS with H&R Springs and stock shocks. The 25.5 hollow is comparable to a 23 solid bar. I found it fine on the softest setting on the track and street. The stiffer settings were good for Auto-X. However, once I added front camber plates with -2.2 camber in front and -1.5 in rear, the car was a little too prone to oversteer for street driving. Letting off the gas in a turn (someone slows in front of you) would make for a little too much oversteer.

I now run a 19mm solid bar with front camber plates. Good combination and very balanced but still can get oversteer for higher speed Auto-X.

 

I've been running most aggressive setting for a while now and I do have to say, it's a blast pulling u-turns.

 

Interesting, We've found the Hsport Comp bar to be by far the best bar for the R53 chassis. Just set it on the middle setting and go, this is our number one R53 sway bar, let alone best selling bar out of all of them. I would recommend it to any customer.

I would be interested in knowing what tires, springs, and shocks you have as this could be a combo causing your issue.

And if you think it's too loose maybe try it on the soft setting.

 

Way;

I'm running full suspension. h-sport comp bar of course, h-sport springs,
koni yellows, spc camber plates, ireland engineering lower control arms, tsw motor mount, bsh lower motor mount, poly bushings up front and rear poly trailing arm bushings on the way...

Side note, the SPC camber plates are off the car right now, (can't wait to get them back on)

 

Ive been running the 25.5 bar for a long while and for the street I would stick to the softest setting, you will also want to pay attention to your tire pressure especially if you take your car into the canyons. After spinning during a track day on the middle setting I dialed it back. After spinning on a mountain road on the soft setting I became methodical about tire pressure. Im betting the soft setting and some driving habits changes will work good for you.

 

What are your alignment settings?

To reduce the oversteer, you can dial in some rear toe, soften the rear Konis (unless you're bottoming out, in which case you should stiffen them,) perhaps run a little more rear camber (or a little less, depending on what you're at now) and / or play with the tire pressures.

It might help to describe the conditions of your oversteer. Is it on turn in? On transition? Mid corner, or corner exit? Steady state throttle or lift throttle only? High speed only, low speed only, or all speeds?

If you can post your alignment specs and answer those questions we can probably (here comes a big pun) steer you in the right direction of adjustments to try. A car must be confidence inspiring first to be fast.

 

Hey all been gone for a few days.

Did a twisty run this weekend with a few friends, and a few of them tell me my car scares them, granted I have way more time behind the wheel then they do, but still its like 50/50, I guess the 25 mm bar is only for the hardcore, out of a few hundred R53's out here only a handful are running close to my set-up...

Burglar;
I have yet to mess with the tire pressures, I usually like them soft not hard for my driving style.

On the alignment specs, don't know, still waiting to get one after I change up the front camber again.

The car is definitely confidence inspiring, sometimes I would say thru transition or mid corner (If I lift throttle, the car quickly slides out)
now If I have the ***** to stay on the throttle thru the turn it quickly pulls me out the slide, very controlled I might add.

Side note: My tires SUCK! I'm running Sumitomo's HTR ZR II's and the tires can't perform up to my needs. Next on the list to buy. New Tires!

 

The thing about stickier tires is that they generally tend to like high slip angles less. That is, when they give up, they let go much harder. Be careful, especially if your car oversteers, when making the upgrade.

Good luck.

 

I'm running 1" lower on BC coilovers, Swift springs at 8k in the rear and 7k in the front, 15" PR1s with Yokohama S Drives. I'm running the fronts 10 clicks softer to get good bite and rotation. I'm thinking about the Comp bar. What do you guys think? I'm pretty happy with it now, but there is room to go stiffer and the Comp bar would allow me to run the clickers more even. I do have the rears drilled for adjustability. Everything else is stock, springs are still settling, so I haven't done an alignment yet.