i installed a strut bar and it made a huge difference with body roll and the jittery front end stability from road imperfections,definitely a must have if you like cornering...also bought the rear wiper delete and a stubby antenna, and made an iphone holder from the plastic tray included in the iphone box,works great...id like to know what accessories people are using,
thanks

 

Glad to hear the bar works well. Even though our CM doesn't arrive for awhile yet, I have a VIP strut bar , and turbo cover sitting in the corner. Next will be a set of DiMisa 4" SS exhaust tips, and the VIP fog lamp kit. Should be a nice pile by the time "Coco" gets here!

 

i got the bar from VIP too, im going to add an intake setup from them as well, 10 more hp sounds fun :D

 

did you both get the strut bar to accompany a sport package, or would it still help a non-sport CM?

 

+1

 

How was the installation? Pretty straight forward?

 

I just picked up the strut bar from VIP, hoping that it'll be here early next week, so I'm excited to see how that will go. I've also got the SprintBooster on order (again early next week delivery); if this thing does what it's says it does, this will likely be the most important mod on my car. That throttle delay is atrocious.

 

Minor, but good. Light in sight and the brake light pulsar. As you can tell by my sig, I've got lot more, but for safety, those two are CHEAP insurance.

 

Please let us know how this works out. I was thinking of getting the SprintBooster, but am unsure of it's real world gains. Will be nice to see what it will do on the CM.

 

I'm also pretty skeptical, but I decided it was time to finally pull the trigger and see what it does. I'll try and resist ripping the box open and installing it in hopes of getting a little bit of scientific method for before and after (but I can't promise anything).

 

Let us know how that works. You're right, that throttle delay is pretty bad.

I had ordered the car with sport suspension and I am so glad I did. It feels more solid - no body roll, and even with the 18" wheels I don't find it harsh at all, nor do my kids in the back. In fact, my son also said that the car felt really solid.

 

i havent driven the non s but a strut bar will help reduce roll on either s or non s, the strut bar reduces flex by "tying" the 2 independent struts together..installation is simple took 5 minutes..im really interested in a sprint booster too, looking forward to hearing the results

 

I have installed a strut bar on every BMW product I have owned (except the R1200RT!). It does reduce the flex of the unibody at the upper shock mounts but it is not nearly as effective in reducing body roll as beefier front & rear sway bars (and adjustable shocks). I would suggest that if reducing body roll is your goal, you first upgrade the suspension with a thicker front sway bar and an adjustable rear sway bar. Just these two changes can dramatically transform the handling of most cars.

Many folks take a "bazooka" approach to suspension changes: shocks, springs, sway bars, wheels, and tires are ALL changed out at once. This can work, but many times the combined changes are too "compounded" for the successful tuning of the suspension. At the worst, the owner winds-up with a too harsh track car ride and punishes their car, their passengers, and their wallet. An alternative approach is to make modifications using a "change then evaluate" method. This is what I have done on most of my autocross cars as they have had to perform street duty as well.

IMHO, the following progression of modifications allows one to carefully tune the suspension to provide a balance between handling and comfort. YMMV on this; it is just my own process and is designed to tune the suspension of a front-wheel-drive car that will spend 90% of its miles on the street.

1. change-out the runflats for a good performance tire (limit the change in height and width to +1 at most);
2. after 15 minutes of spirited driving, establish baseline tire pressures by tire temperature taken across the tread width (at three places on the tire's circumference) using data from the outer, middle, and inner tread -- your goal is to attain even temperatures across the tread of all four tires and record the pressures (if middle temp exceeds outer/inner temps, reduce pressure; if outer/inner temps exceed middle, add pressure);
3. EVALUATE: are you satisfied with the result? If not proceed to the next item;
4. replace the front and rear sway bars with slightly larger diameter ones (generally, 15-20% larger) making sure that the rear sway bar is adjustable to at least three positions (and that you start out with it set to the position that allows the most torsion/flex);
5. repeat Step 2 -- establish new pressures;
6. repeat Step 3 -- evaluate: done or continue;
7. move the position of the rear sway bar adjustment to the next (less flex) setting;
8. repeat Step 2 -- establish new pressures;
9. repeat Step 3 -- evaluate: done or continue;
10. move the position of the rear sway bar adjustment to the next (less flex) setting;
11. continue the above three steps until you have found the best setting;
12. finally, counteract the increase in stress you have placed on the front part of the unibody by adding a strut brace.

For most folks who will not be constantly using their car on the track, this is the least expensive way to dial-in a street-based suspension. Unfortunately, you are not supporting a myriad of aftermarket manufacturers and you are flying in the face of the "traditional wisdom" given to you by all your overly-accessorized acquaintances. But the results can be very well balanced and can make you car more pleasurable to drive on the highway, the twisties, and on the occasional rough road.

If you absolutely MUST give away more money to aftermarket manufacturers, get a set of compression and rebound adjustable shock absorbers. When setting the adjustments, your front shocks should wind-up at a more compliant setting and your rears at a less compliant setting. Remember to make small changes, check your data (tire temps), and adjust your pressures after each change.

FWIW,

 

Koopah, im not flaming you and your tuning solution is obviously effective for what youre after, its also not an inexspensive venture..between tires,heavier bars,strut braces,dont forget the temp gun, youve got a $1500- $2000 parts bill, then put time/labor ontop. Strut bars provide a great improvement of front end stability for not alot of money from an aftermarket co providing proven alternatives to completely redoing your suspension, just my humble opinion

 

They do help control the deflection of the front suspension/unibody geometry, but I will have to respectfully differ with you on the degree to which they have an effect on body roll. The M7 strut bar on my MCS only produced a difference in "feel" and did not affect body roll at all. However, the perceived effect (as communicated via the steering wheel and felt through my butt-dyno) was, for me, (1) a sense of less "slop" over rough roads and (2) a slightly better "turn-in" feel.

Body roll is primarily controlled by a combination of sway bars, springs and, to a lesser degree, by shocks; the suspension geometry is only slightly affected by the deflection of the unibody. The loads presented by body roll do not significantly deflect the points on the unibody to which the suspension is connected. Instead, body roll exerts almost all of its major loading on the "flexible" portions of the suspension components (tire sidewalls, sway bars, springs and, to some degree, shocks). To address actual (vs. perceived) body roll means making changes to these components.

However, in the end, it is how happy you are with the handling of your particular car and the changes you have made to it. If your senses tell you a strut bar has reduced body roll, you will be a happy camper!

As always, YMMV!

 

Sways are definately a more expensive way to go, but if you're trying to reduce body roll, that is where you start.

See link on strut bars.... I do have them on my other cars and like the stiffer feel but they will not make any difference in a CM's body roll...

http://www.e30m3project.com/e30m3per...bar_theory.htm

 

Black Box

This thing is amazing with Google Earth GPS tracking.

http://www.boyovta.com/products/vtr104.html

 

I've just posted my installation of the SprintBooster to my blog. While I have no real cold hard facts, it certainly feels like it's doing what it's supposed to. Off the line Norman finally seems to respond a lot quicker than he used to. I need to come up with a way to really test it, but for now it at least feels good.

 

Gentlemen, when "firmly" cornering on a slightly rough road our CM seems to bounce sideways to a different line exiting the turn. Will a front sway bar lessen or eliminate this phenomenon?

 

Is this your first MINI?

A front sway bar will give you a more positive track, but in my opinion could make the bounce from a rough road much worse. Let's get the experts opinion before you listen to mine.

Michael

 

The dynamics of your stated situation need to be clarified. I am (perhaps wrongly) assuming that since you are "exiting the turn", you have passed the turn's apex and are beginning to accelerate out of the turn. I also assume that you feel BOTH the front and rear tires getting loose since your exit line is being altered by the road surface. Is this correct?

Another take on this would be that you are braking around the turn or at neutral throttle and not accelerating. Different still, would be that you are accelerating out of the turn and the front tires are not slipping but the back tires are, causing the rear to "step-out" versus both the front and back seeking a new line.

Other info that may help:

1. do you have an All4?
2. do you have the sport suspension?
3. what wheel/tire combo are you using?
4. what tire pressures are you using?
5. any aftermarket modifications?

Generally speaking, when the a vehicle "steps-out" over rough road, it means that the rear suspension is not compliant enough for the road surface, or that the rear shock damping is too weak. That is why off-road race vehicles have very long suspension travel, carefully engineered shock design/valving, and specially-tuned "progressive" springs (compress easily for minor bumps but firm-up as the suspension travel increases).

That being said, tuning a vehicle for rough roads can produce some undesirable behavior on normal roads. Tuning a vehicle for normal roads can produce undesirable behavior on rough roads. Suspension tuning is usually a compromise between these extremes and, in production cars, is usually very significantly biased toward normal road travel.

As to your question about a larger diameter front sway bar helping the situation, I'm not sure that would be the best way to approach the solution. Assuming that the rear end is stepping-out, I would first address the issue through a modification of driving style over rough surfaces. You could experiment with adding a bit of feathered throttle sooner than you usually do to help transfer a bit more weight to the rear suspension for the rough surface. Just be careful to do this modestly as weighting the rear will un-weight the front and you don't want to do that too much when you are asking the front wheels to pull 3,000+ pounds around a corner!

The next thing you may want to look at are your tire pressures. Most people seeking better road handling (NOT track tuning) mistakenly over-inflate their tires. This can reduce compliance and cause a "jittery" feeling over rough road. The best tire pressure allows for the tire temperatures at three points across the tread to be as close to the same as possible.

Borrow a probe-type pyrometer from a friend who autocrosses and find the right pressures for your CM and your driving style. You don't want to use an IR temperature sensor as it reads only surface temperatures; a probe-type pyrometer reads the temperature inside the rubber and produces more valuable information. HERE is a brief explanation of the process.

HTH,

 

Many thanks for your replies!!

Yes this is our first MINI.
No to the All4 and sport suspension.
Aluminum wheels with 16 in all weather run flats from the factory.
Standard tire pressure with nitrogen.
No other mods.

You are right that the issue is accelerating past the apex and it's not the back stepping out. The whole car shifts much like a go cart does. I'm not that agressive a driver but this does tend to scare the passengers.

Maybe "sway bar" is not the right item. Is the sway bar the addition that goes directly under the hood and attaches to the tops of both shock mounts?

As you can see I'm not a car guy but might want to be someday so talk down to me and any little bit helps.

 

That this is happening on rough roads only and includes both ends shifting indicates that there is really nothing amiss. This effect might be more pronounced with the sport suspension as it tends to make the car a bit less compliant over rough surfaces. I think as you drive the MINI more, you will be able to feel the onset of the "shifting", at which point an even more modest throttle will keep it under control.

One rule to remember about getting the most traction from a front wheel drive car is to not add much throttle until the front wheels are pointed directly down your exit line. This is one advantage that the FWD arrangement has over RWD: you can get on the throttle sooner when exiting a turn.

No. The sway bar connects the bottom of the struts to each other underneath the car. If you take a wheel off and peek around the bottom of the hub, you will see a ~18mm bar attached to it and curving under the car. This bar is really a torsion bar that limits (dampens) the compression of the springs and struts and, thus, reduces body roll.

You are thinking of a strut bar, which does nothing for body roll. It does, however, reduce the "deflection" of the front suspension geometry under high-G cornering. When the geometry deflects under these race-loading conditions, it can adversely affect the camber of the front wheels and affect handling. For a street cars, a strut bar may help the steering to feel a little tighter on rough roads and, under certain conditions, may give the feeling of a bit better turn-in. IMHO, I don't believe a strut bar will make one whit of difference in taming your issue, however.

You may wish to double-check your tire pressures with an accurate gauge. I sounds like the behavior of a vehicle with a too-stiff suspension (yours isn't) or with its tire pressures set too high (maybe?). Try "chalking" your tires to see if the full tread is being used. Even the "standard" pressures can be off. The following video shows the principle of tire chalking, even though it is on a Jeep with 37" tires!!

Chalking Tires (note: contains some language that may be offensive!)

HTH,

 

Here is another explanation of how to chalk your tire for an approximation of the proper air pressure. Using a pyrometer to modify pressures via temperature readings is way more accurate, though.

"...here is the two-dollar chalk method.

At the track, or on your favorite curvy stretch of road, take some chalk and mark all four of your tires. Make the mark across the tread portion of the tire, around the edge, and about an inch down the sidewall (about where the lettering starts on the side of the tire).

After making a few passes through both left and right hand curves, pull over and check the tires. What you hope to see is all the chalk rubbed off the tread on the tires, and almost all of it still on the sidewalls. How much is almost? If you've only rubbed off one sixteenth of an inch of the chalk on the sidewalls, that's good. If any chalk remains on the outer edges of the tread, you have too much air pressure. If the chalk is rubbed off down to the lettering on your tires, you've got way too little. That's as close as the chalk method gets. It lets you know that you're not at the extreme end of either spectrum. Pyrometers work a little differently..."

From a post HERE.

BTW -- chalk sometimes doesn't rub onto tires very well. I've used tire crayons and much prefer them.

 

Switch out the run flats with normal tires. The rock hard sidewalls of the run flats are unforgiving and don't cushion the rough road causing the bounce/tires to loose traction. fx.. two rocks collide, they bounce. a rock and pillow hit each other, the pillow (your tires) will absorb the blow and keep contact on the rock/road.

Koopah- you're incorrect with your fwd vs rwd assessment below... rwd lets you to step on the throttle throughout the turn leading to much higher exit speeds than FWD. that's why most sports cars are/were RWD. topic for another thread though.