Despite new great shocks (KONI FSD's), non run-flats, and front control arm bushings, the "bump steer" (might be the wrong term) is still bad on my car. The steering often has a very potentially dangerous mind of its own when you go over bumps, and this has nothing to do with the fact that it's FWD -- I've driven other high-powered (although the engine itself has nothing to do with this particular problem, since I'm not talking about torque steer -- repeat: I'm NOT talking about torque steer ) FWD cars that did not exhibit this problem anywhere near to the extent of the MINI. And the funny part is that people I know who had R53s and now have an R56 say that the problem was not nearly as bad in the R53...?

So my question is this: let's say that money is no object and one wants to do whatever it takes to help alleviate this problem. It would take an actual rebuild of parts of the suspension since the other things I've tried barely do anything for this particular problem. I love this car but hate the unsettling and downright dangerous meandering that the steering often does over bumps, and I've experienced this in every single R55/R56 I've ever driven (and I've driven a good amount of 'em). If it's not absurdly outrageous I would consider doing whatever it takes to make this car solid in this department.

Do NOT take this personally! MINI/BMW is just a corporation. I love my MINI but want to improve this one area that badly needs improvement, in my personal opinion. If you have a different opinion then that's totally cool, but let's just stick to this topic on this thread if we can.

Over a year ago I test drove a VR32 GTI with 17" wheels and very low profile tires and it barely had any of this problem, so it CAN be done in a high performance FWD car. I want to find out IF it can be done to a MINI and if so, HOW it can be done.

Looking forward to reading about it!

Cheers,
N

 

I do not feel the same as you. I have the JCW suspension on my car and I drive in the NYC area. We have some very poor roads around here not just potholes either.

Driving my car in this area does not make me uncomfortable nor do I feel the need to rebuild the front suspension of my car.

I am considering the OS Giken LSD but other than that I am not looking at making any other major investment in my car.

 

Maybe the JCW doesn't have this issue? I'm glad you don't have the need for more investments, but I'm not in the same boat, so...

I've seen and heard many, many people complain about it so I know I'm not alone; I've even seen it mentioned in some reviews, too. I just did a search on the forums here and it comes up quite a few times from different people. Perhaps the JCW has something that helps with the problem...if so I'd like to find out what it is! It's not over huge holes or bumps that it does it, actually -- for some reason it seems to be more over smaller bumps/holes/anomalies.

 

Headlands, you have brought to my attention "bumpsteer" which is certainly more interesting than, "What rims should I put on my car?" Perhaps I lead a sheltered life, but I'll admit that I had to go to Google bumpsteer.

Not to simplify it but I understand that bumpsteer occurs when the front wheels pass over a bump that is sufficient to cause a momentary change in the toe. This in turn has the tendency to make the car feel that is wandering, as we notice when toe is not set to spec. Most noticeable if it's negative.

I haven't felt this in my R56, but that's not to say it isn't there. (I may be a numb butt.) Since you have made some suspension changes, I wonder what you have found. Have your changes helped or have they made it worse.

I'm looking forward to hearing what our "track" buddies have experienced, since I assume any problems with steering geometry would be pretty high on their list. Let's hope there's a simple solution.

 

I've found that the suspension upgrades have made a noticeable and positive improvement in other areas of handling, but not for this so-called bump steer.

When I went on a MINI "driving day" with 4 other MINI people a few months ago, we all talked about this problem and everyone there also experienced it in their cars (mine is an R55, theirs were R56). It might not bother some people, which is totally cool! I find it to be dangerous and un-nerving, so I'd like to find out if there's a way I can minimize it. Like I said, nothing I've done so far has really improved this aspect.

I'm not going to be critical any more -- I'd just like to find a solution, if there is one.

 

I am not syaing that I have not experienced it. I have. It does not concern me enough to take action meaning replacing or upgrading suspension components. I have concerns with other shortcomings that I am trying to address.

Besides the new springs and shocks the JCW suspension add a thicker front and rear sway bar. I replaced the rear sway bar with the H-Sport competition rear sway bar which is a hollow 25.5mm bar that acts like a 22.5 rear sway bar.

 

I have heard that lowering improves the problem quite a bit. I'll report further when I install my PSS10s

 

Hmmm, interesting. I personally don't want to lower the car, though...I feel like there should be a way to improve it without lowering. It may involve reconstructing sections of the entire suspension -- I remember someone mentioning two parts that need to be the same length to help with this problem, but that they aren't equal in a MINI...?

Unfortunately the things that are supposed to help that I've implemented (new shocks, poly front control arm bushings, non run-flats) simply don't help, in my experience. They make the car handle better and improve the ride but they don't do a thing for "bump steer" or whatever this is known as. Other things like lowering the car seem more like band aids -- instead I'd like to find out how to re-set the actual broken bone.

I know it probably won't be cheap or simple, but I've gotta to try to make it happen; especially since I've driven other similar style cars with the same size wheels and low profile tires that don't or only barely exhibit this behavior.

 

The FSD's don't have damping adjustability, do they?
As in able to adjust the compression rate valve in the strut-body.

For clarity reasons, are you getting:
A.) when hitting a bump, the steering and car direction is changing due to suspension geometry jounce (true definition of "bump steer") ...OR...
B.) when hitting a bump during cornering are you feeling the sensation of the vehicle skipping across the asphalt?

Based on your limited explanation of your car's physics, I'd say that your struts don't have enough compression.
But that's a preliminary observation, and awaiting more information from Headlands before suggesting other options.

- Erik

 

Hi erik, and thanks for the response.

FSD's are "Frequency Selective Damping", and are not adjustable. But they get rave reviews across the board on different cars for their handling qualities so I assumed that they would be OK. They're certainly noticeably better than stock for both ride and handling, but don't address this specific issue that MINIs have.

I experience both of the things you describe. My friend (a fellow MINI owner who has a stock R56 S) and I were talking about this issue, and he was telling me that sometimes it feels like he's steering in one direction and his R56 wants to go in another for a split second, and that it also sometimes feels like he's "floating" during cornering, both when hitting bumps/uneven pavement. So both of your descriptions are spot on.

 

Hmmm... assuming that trie pressure isn't outrageously high, and alignment specs have toe at 0" - 1/16":
I'd say you have either too weak of compression valving in the strut for your driving habits...
Or the spring rate is not sufficient allowing the tire's contact patch to lift from the ground.

I'm in a similar boat only with the skipping issue only as described, but that's attributed to my run-flats are still on my R55 JCW.
With my spirited-driving techniques to work, I know the tires are currently the limiting factor.
Lowering the air pressure to a range of 30-35psi has helped with steering wheel feedback and increased control faith.
Yet, once I remove those pesky run-flats, I'm wondering where I'll stand in comparison to your case.

Right now I'm documenting weight distribution and wheel load on my R55 JCW and planning a full coilover system to properly balance the vehicle.
However, that install isn't coming till spring 2011 and unfortunately can't get you any real-world experiences until such.

- Erik

 

I've tried lowering the air pressure in my tires -- right now they're at 35 PSI. It helps the tiniest bit if I go even lower, but then one sacrifices sidewall stiffness in cornering. For me, changing to non run-flats improved the ride and overall handling but did nothing for these specific issues. I also had the alignment checked twice since I've bought the car (once at the dealer, once at the tire shop) and toe was within spec. Should I try changing toe? Would that possibly help?

It's independent of driving habits -- I can be driving very non-aggressively and these problems don't go away. If what you're saying is true about spring rate and/or compression, then stock MINIs also have the same problem since every MINI I've ever driven has these same issues. I've had two MINI loaners during warranty work and they both had the same issue. One was an R56 non-S with 16" wheels and one was an R56 S with 17" wheels. Based on these and other MINIs I've driven, and after talking with more than a few other owners, my conclusion is that it's just poorly designed and/or poorly implemented, unfortunately.

Would there be a way for me adjust the spring rate so I can see if that works, or would I need to buy new springs? I'm leery of doing other mods without knowing for sure, because so far everything that has been recommended to help with this problem has done very little to nothing.

 

You should call up one of the shops that are MINI specific like Helix, WMW or MINI-madness etc. You are going to have a much better conversation with one of those guys then waiting around for some one to post in this thread.

 

That's a damn good point! I'll call a few different places this week and report back for anyone else that's interesting.

 

I would say its because the tires are not wide... still on factory rims?

 

I happen to have wheels that are 7.5 inches wide on non-runflat tires and I still experience this over bumps. For the most part I ignore it, but like Headlands I find it to be somewhat annoying. I totally get where he's coming from . That being said, I've figured that this is something I'll just deal with until I possibly find something to alleviate the problem on it's own. Maybe those expensive coilovers I'm saving for will help. If not, then no biggie in my opinion. Good thing the roads in my area are pretty decent I guess .

 

X that out then, i figured it was because of the small contact patches on factory tires...

I know what he means i have gone over rough road during a curve... not even bad road just rough and had it bumpsteer so bad the dsc kicked on.

 

Spring rate change would require swapping out different aftermarket springs...
Or permanently changing (cutting a coil out) the existing OEM springs which isn't recommended on any level.

I don't blame you; but we're hopefully digging to the heart of the problem.

Part of it is the "increased" comfort design criteria from the raw-felt 1st-Gen to the softer 2nd-Gen.

- Erik

 

While I agree to this to a point, especially since NAM is on the lesser side of a technical forum compared to other forums. If you call all of them and talk to them, you'll probably be asked (BY MOST, not ALL) what parts you have, and whatever you don't have upgraded that they carry, they will try to sell to you with some (partially true) reasoning. Remember a business is there to be a business. You can find the exception once in a while for someone who really talks to you as a friend rather than a sales person. But normally you'll find yourself being talked into buying additional parts without scientific reasoning.

"A Larger rear sway bar will decrease understeer in the car. You should buy a 22mm sway bar"
vs
"A larger rear sway bar adds ____ to the car's rear suspension components by xx %, causing ___ to be % more, thus reducing body roll by yy% and increasing front grip by zz%. However, stiffness of the body and NVH will increase by % etc etc"

Whether those statements above are true or not, they are significantly different.

All I'm saying is yes, tuner shops can definitely be of help, but just becareful how you take each of their advice.

To add to your concerns, I experienced bump steer at stock height with 18" JCW R105 wheels, but lowering (lower center of gravity) decreased not only bump steer but also torque steer. That is... until I got tuned, now i fight the steering wheel quite a bit. How wide are your tires btw? You may experience a combination of tramlining that makes the bumpsteer seem worse.

 

As bluefox mentioned....bumpsteer and lack of grip over bumps are different things. There are so many things going on with the suspension on this car that it is difficult to pinpoint one thing at a time.

Bumpsteer is really dynamic toe changes as the suspension is compressing or extending. This can be from a "bump" or during body roll in a turn on even smooth roads. I personally do not feel an excessive amount of bumpsteer in my R53 (stock suspension) in day to day driving.

Lack of grip over bumps is a much larger and more noticeable problem though on the crappy mid-atlantic roads that are perpetually under construction. The Mini is very "bumpstop active" and has very little travel. Coupled with crappy shocks with not enough compression and too much high speed rebound for the soft springs, grip and comfort on anything but smooth roads is hard to find and can be a real pain. The car can really bounce around a bit but I don't think i feel it pulling itself much. It gets hairy and pulls from side to side in low grip situations when the DSC kicks in though...very noticeable and annoying in the rain or snow.

EDIT: crap....i have an R53 not a 2nd gen. Things could be different.

- Andrew

 

Made some suspension changes a couple of weeks ago, largely based on the afore mentioned "bump steer" On a particular sweeping exit ramp with an expansion joint, I thought I was about to be launched into the next lane! Unnerving to say the least.
After reading other theads and trying to get an idea of what to do without breaking the bank, thanks to tvrgeek, orangecrush, andyroo, scottab36, and a host of others, I purchased a set of Bilstein HD's.
I also went with NM springs, mainly because I was taking it apart anyway, but also because of the positive reviews. I know Bilstein makes sport shocks for lowered springs (read more $) but after all the Bilstein's are heavy duty, and I may only get 99,999 miles out of them.

Bottom line PROBLEM SOLVED! Same road, same as going over a tiny crack on the straightaway. And as an added bonus, it seems that 99% of the torque steer has vanished.
I'm running 17 inch wheels, although have just switched back to stock 16 inch runflats for winter, still rides great. 2010 R56 MCSm.

 

That's excellent news to hear.

So there lies some user-owned truth about too soft of OEM suspension components. Bummer Maugre that you didn't have the time to test out either whether the problem was solved from just the shocks/struts or the springs, or truly the combo of both.

- Erik

 

Excellent feedback! So it is not a geometry "bumpsteer" problem but a crappy OEM shock and poor damping problem.

- Andrew

 

Excellent to hear. I wonder if I would get similar results if I put new springs with my Koni FSD's... The Konis are fantastic shocks that are miles above the junk that comes with the MINI.

Would I have to lower the car if I get new springs? I REALLY do not want to lower it -- don't care for the look and am hitting curbs, etc., already with the front of the car.

EDIT: Just called Koni and they advise against lowering of any kind with the FSD's on a MINI. Crap. The shocks are so great that I'd hate to go with others...FSD's are an amazing balance of improved ride AND improved handling from the OEM setup.

 

I'm pretty sure there are replacement springs available that will work with your setup. I wouldn't put lowering springs on Koni FSD's anyway. It isn't good for them. Sadly, that's pretty much the extent of my expertise on that subject. Knowing that they exist and knowing where to find them are unfortunately two different things . Seeing as you have both andyroo and bluefox280 helping you at this point, I'll defer to them since they know a lot more about suspension then I do and I'm sure they can help you pick out the correct springs. Having said that (and at the risk of looking foolish), I'd suggest that you check to see if Swift makes springs that will work for you. They are supposed to have awesome quality .

Caveat: I might be thinking of replacement coilover springs as I write this, so take what I said above with a grain of salt.