I've added the strut brace on my 2009 R56 with original stock suspension and the bump steer did not improve. I believe my bushings are very worn too as when I change gears (manual) the car does rock significantly more than it used to. I heard this goes away when the suspension is replaced. All this with an NM engine mount installed a couple years ago.

 

My understanding of bump steer is when hitting a bump while turning the car lurches to the side.

My R59 with only 10k miles on it would shift to the right about a foot (it feels like) on a particular banking freeway ramp when hitting a bump, think shallower turn than a freeway clover leaf. I understand this to be bump steer.

I experience something similar on bumpy roads when going around curves.

According to this thread a LSD helps with bump steer.

https://www.northamericanmotoring.co...ml#post4109783

So at around 50k miles I will put in the Koni FSDs; and at around 65k miles when I probably need a new clutch, I will also get a LSD installed.

 

I put in Koni FSDs, all new bushings (front and rear), new motor mounts, and while the ride quality improved significantly (it was metal on metal harshness), the bump steer remains outrageous, and dangerous...on my 2008 R56 S. 2 hands are a MUST on turns.

 

I'm in the same boat with my 09 Clubman JCW. I can hit a bump in the road with my steering wheel turned slightly and it will jump about half a foot, so it feels. I'm running stock suspension, almost 80k miles. I have Sumitomo HTR ZIII tires, not sure if theyre run flats or not, they came on the car when I bought it. I thought about going with some 18's and coilovers, but with the bump steer as it is, I'm questioning that option.

 

The only thing that helps a TINY bit is reducing tire pressure a few pounds down to 35-36 psi as opposed to the 39 Mini calls for. Koni FSD struts on stock springs didn't improve bump steer. Regular tires might help...but I wouldn't know since I bought mine with almost new run flat Contis.

 

Yea, I may do that. My tires are pumped too tight anyways.

 

haven't noticed much per se, short wheel base light weight also contributes I'm assuming. also imagine depends on how much suspension travel you have before reaching the bumpstops - mini typically has almost none.

 

I think we have very very different interpretations of what bump steer or we are driving different cars. The amount of bump steer on my 2008 R56 with both full OEM suspension and OEM springs with Koni FSD struts is astounding.

Hold that steering wheel TIGHT.

 

Bump steer is technically the amount that the toe changes when the suspension moves. Typically this was common on older cars, but most cars today have minimal bump steer.

Now it is not uncommon for a car to become unsettled while cornering and hitting a bump. If the suspension does not have enough compliance to absorb the bump without disturbing the car, then the car will become upset. Like stated above, there is not much bump travel on the suspension until the bump stops are contacted, which become pretty stiff pretty quickly.

Solutions mentioned above make sense: Softening the tires, keeping both hands on the wheel. The biggest thing is to be used to the car, and be aware of the road.

With my car I get caught off guard usually with the rear axle. Maybe because I have a fairly stiff RSB. I rarely have issues with the car steering itself when hitting a bump, or maybe I'm just used to it.

Have fun,
Mike

 

Mini ****ed up. The suspension design = unsafe.

 

Sorry, but I disagree. I've got 60k miles on my car since I got it, and have never considered it unsafe. And we don't have nice roads in the Buffalo, NY area.

I can tell you that replacing the front control arm bushings did improve the steering feel on my car. Some guys say the bushings only last 50k miles. The ball joints are tight on my car, and these are generally reliable (3 per side) according to what I've been told and read.

I'm happy to discuss what I've learned working on my car.

Have fun,
Mike

 

He says, she says....

Some of us experience extreme bump steer when going around a turn and hitting bumps. Others don't.

My entire suspension is new. All new bushings to boot, ftont and rear. The car did the same thing when it was new.

Clearly we have different interpretations of what extreme bump steer is or we drive very differently.

 

^ are your shocks/struts new as well? Changing out the stock struts for Ohlins R&T cured this for me. In my experience the stock struts do not deal well with sharp bumps, they are too stiff. There's an expansion joint right in the middle of a high speed freeway interchange that used to be a bit exciting, with the Ohlins now it is just a distant thump.

 

Does it lurch in or out?

My R53 put me into a gutter lurching out to a wider line after hitting a bump when turning. It was front control arm bushings. Changing to a poly bushing has made the problem go away. I can't say it is definitely gone because my parents moved house so I don't go round that corner anymore, but I haven't had anything even remotely similar since changing them.

James

 

Brand new Koni FSDs on OEM springs.

 

Nope. No lurching. Ever drive a full size truck or something with an old school live rear axle and go around a turn at speed and hit some significant undulations or potholes? Remember how the rear end bumped over to the outside? Well the Mini's front end does the same thing. Since new. It has to be a significant bump.

 

Don't think that is bump steer then. Bump steer is technically a change in toe angle through the suspension stroke, trucks bounce out because they have hard suspension and the wheels leave the ground. Either way it sucks!

Have you seen the roll center adjusters made by a few companies? Could be worth a look if you aren't sick of throwing money at it yet.

James

 

Well, let me clarify. Its bump steer plus a nice hop to the outside. Holding on with 2 hands is a must when engaging large imperfections at speed in a turn.

Roll center adjusters...hmmm....never heard of them. I will look into it.

Thanks James.

 

Roll center adjusters won't help...in most cases for the MINI they will increase bumpsteer if not designed correctly (and I don't think I've seen one done right).

What most of you I think are feeling is a lack of suspension travel, bottoming out, and poor compression damping. The MINI has short compression travel and is very bumpstop active, plus the stock shocks are crap. It will bounce off bumps and that's pretty noticeable in a corner if the suspension is already loaded up. It's not necessarily "bump steer" which is toe changes throughout the range of suspension motion.

- Andrew

 

Andrew, thanks for your thoughts. I know that Car and Driver mentions that the regular Cooper has a much better ride than the S. Even on the newest gen Coopers. So perhaps its just spring rates, unless total suspension travel changes markedly between S and non-S cars.

I did switched to Koni FSD shocks on stock springs and the "bouncing off of bumps" problem persists.

 

^exactly. Bump steer is not bouncing off of bumps. Car going wide after hitting a bump while cornering usually means bad shocks, bad bushes, bad ball joints or bad tyres. Or just too much speed going in to the corner.

Bump steer can be felt as a change of turning circle as the body rolls while cornering. No bumps in the road needed. The "bump" in the term "bump steer" actually means suspension deflection. On the Mini you usually get bump steer only if the car is lowered, and it makes it turn tighter as the body rolls. Not a nice feeling at high speeds, induces oversteer too in certain situations.

My R53 is lowered on Bilstein B14 coilovers and I do track driving quite a lot, and the lowering did introduce quite a bit of bump steer. I also put roll center adjusters on mine, but they didn't really help... I guess no-one makes bump steer spacers for the Mini?

 

Might read this from Fat Cat Motorsports as well since they make a direct replacement shorter bump stop, which helps keep the car from hitting them during hard cornering or harsh bumps.

http://fatcatmotorsports.com/FCM_Products_Mini.htm

 

Jko, ok so then let me call it a lack of suspension travel.

Agbullet, thanks for the info on Fatcat suspension bump stops. I forget what the OEM stops look like, but maybe cutting them would do the trick. I have other cars that are lowered and shorter buympstops are sometimes required.

I am tempted to try regular Cooper springs with my FSDs. It's my girl's car and she doesn't like the harsh ride.

Anyone know if Justa springs will fit?

 

I just bought fatcat bump stops to get on with my FSDs. Don't know when I will have the time to do it, but will update with my impressions once it is done.

James

 

All springs made for an R56 should fit. The only difference is the spring rate between a Cooper and a Cooper S spring. If you run too soft a spring, it could introduce a whole set of new problems with handling.