[MarkW19]

Just wondering if someone can give me some advice.

I've got a 2006 Cooper S Works (as many of you know), with KW v2 coilovers (set about 40mm lower than standard, and on a medium "hard" setting), eibach front/rear anti-roll bars, JCW front strut brace, and Goodyear Eagle F1 tyres (215/35/18) set at a variety of PSIs that I've been experimenting with. My wheels are 18" OEM GP wheels.

Basically, my handling is crap. It shouldn't be, it should be amazing with the above mods! It understeers like crazy, wanders about quite a bit while cruising on the motorway, and it just doesn't really inspire confidence - the tyres barely seem to grip a lot of the time and it's just guesswork where the car will go. The steering also feels quite light, and sometimes unresponsive - the wheel has to be turned quite a bit before much happens with the steering, and it definitely isn't very positive or tight/sharp. My older Cooper was....my Works isn't - and never really has been.

In contrast, I'm currently in a 1.6 BMW 1 series for a few days as a courtesy car (with runflats and obviously no mods), and this handles loads better than my car. Not only is the ride much smoother/softer/better (mine's crashy/hard as hell, even with the KWs on quite a soft setting), but the steering is EXTREMELY responsive - it's point and turn, very sharp, very responsive (although quite heavy, but I like that). I also feel much more confident throwing it about while cornering fast, you just know it's going to go where you want it to. It's incredibly sharp and a great handling car.

BUT, surely it should be the other way round? My MINI with all it's mods should handle a lot better than the 1-series.

I've been trying to get to the bottom of this handling issue for about a year now, but no-one seems to have any serious ideas or answers.

Can anyone help?

[MINIAC]

What size are your front and rear sway bars?

[MarkW19]

Quote: Originally Posted by MINIAC (original)

What size are your front and rear sway bars?

The rear is 19mm (2 settings - soft/hard, set on soft).

The front is 25mm (only 1 setting).

[MINIAC]

Why did you go with a larger front sway bar?

Have your tried your rear sway bar on the hard setting to dial out some of the understeer?

[MarkW19]

Quote: Originally Posted by MINIAC (original)

Why did you go with a larger front sway bar?

Have your tried your rear sway bar on the hard setting to dial out some of the understeer?

Because the Eibach bars come as a pack (front/rear) and are designed to work together. I had only the rear Eibach bar on my Cooper (still on the soft setting) and the handling on that was amazing.

I've been advised against putting the rear Eibach bar on the harder setting because apparently it can be too extreme and induce oversteer quite a lot, particularly in wet/icey conditions and when you push it, which isn't too good on public roads

I've a feeling it's not the anti-roll bars though - the car just seems to "drift" round corners sometimes and not be sure-footed, it's hard to explain.

[Bhozar]

Have you tried it with a different set of wheels? Those large 18" wheels may not be helping. Switching my wheels for 17" OZ Superlegras with Eagle F1's made a huge difference to my car.

Maybe try the firmer setting on the rear bar, and find out if it does produce oversteer, or if it just matches the front to give you more neultral handling.

My wheel alignment is set to the factory standard, but with 0.2 toe-in on the front. All handles very well. Local tyre guy did it.

[beatbox]

Hi,does the car feel unstable under very hard braking from high speed,like the front end is snaking looking for grip? And twitchy on bumpy B roads?
I had this problem and swapped from 18" wheels to 16" wheels,made a slight improvement.
In the end it turned out to be excessively worn track rod ends

[roland2003]

Hi, a few things to try:-
Refit stock anti roll bars
Raise car (-40mm is too low, go for -25mm)
Check front tracking, (just go for zero toe for now)
Tyre pressures, just try 32 front 30 rear (cold)
Check for play in track control arms, front struts , balljoints etc.
Use 17" wheels
Try our Upper Strutbrace. and a set of Bilstein PSS or PSS9.
Our car has very limited handling mods yet is the best handling Mini Ive driven.....very neutral ,and good feedback.
Best Regards Roland GTT

[MarkW19]

Quote: Originally Posted by roland2003 (original)

Hi, a few things to try:-
Refit stock anti roll bars
Raise car (-40mm is too low, go for -25mm)
Check front tracking, (just go for zero toe for now)
Tyre pressures, just try 32 front 30 rear (cold)
Check for play in track control arms, front struts , balljoints etc.
Use 17" wheels
Try our Upper Strutbrace. and a set of Bilstein PSS or PSS9.
Our car has very limited handling mods yet is the best handling Mini Ive driven.....very neutral ,and good feedback.
Best Regards Roland GTT

Hi Roland, thanks for the advice. Why do you suggest fitting the stock anti roll bars back on? Shouldn't the Eibach bars give an improvement? And, shouldn't the lower the car is (within reason), the better it handles (lower centre of gravity etc.)? I'll get all the front suspension components checked out, and tracking checked etc. Really don't want to go back to 17's though...but I did also have this problem with my 17" bullets briefly, before I got the 18's. Also, the KW v2's were fantastic on my Cooper, so I wouldn't think it's the actual product - just probably a set up issue somewhere?

Quote: Originally Posted by Bhozar (original)

Have you tried it with a different set of wheels? Those large 18" wheels may not be helping. Switching my wheels for 17" OZ Superlegras with Eagle F1's made a huge difference to my car.

Maybe try the firmer setting on the rear bar, and find out if it does produce oversteer, or if it just matches the front to give you more neultral handling.

My wheel alignment is set to the factory standard, but with 0.2 toe-in on the front. All handles very well. Local tyre guy did it.

I'll try the rear bar on the stiff setting, need a trip down to Lohen I think! Definitely keeping my wheels though

[MarkW19]

Quote: Originally Posted by beatbox (original)

Hi,does the car feel unstable under very hard braking from high speed,like the front end is snaking looking for grip? And twitchy on bumpy B roads?
I had this problem and swapped from 18" wheels to 16" wheels,made a slight improvement.
In the end it turned out to be excessively worn track rod ends

Yes, it does...but I kind of expected braking issues with the FWD/short wheelbase etc. It also tramlines quite a bit which is to be expected.

So, switching to 16" wheels only made a slight improvement? The worn track rod ends was the main problem? Did you replace them and it sorted everything out? My car is barely a year old, with less than 10k on it...

[beatbox]

Quote: Originally Posted by MarkW19 (original)

Yes, it does...but I kind of expected braking issues with the FWD/short wheelbase etc. It also tramlines quite a bit which is to be expected.

So, switching to 16" wheels only made a slight improvement? The worn track rod ends was the main problem? Did you replace them and it sorted everything out? My car is barely a year old, with less than 10k on it...

Yes,the problem was an offside defective track rod end,after renewal the car is back to normal,the part only costs £43 from dealers.My car only had 15K on it but the problem started well before that.

When i first took it to dealers for a check up ( 12K) because it felt unstable under braking they said it was worn rear discs.I renewed but the problem remained.

[MarkW19]

Quote: Originally Posted by beatbox (original)

Yes,the problem was an offside defective track rod end,after renewal the car is back to normal,the part only costs £43 from dealers.My car only had 15K on it but the problem started well before that.

When i first took it to dealers for a check up ( 12K) because it felt unstable under braking they said it was worn rear discs.I renewed but the problem remained.

How did you find out it was that that was causing the problem?

[roland2003]

Yes weve seen a few cars with one (very) defective track control arm. Grab the wheel at 3 and 9 O'Clock and push/pull. Its pretty self evident , the slop is easy to feel,....compare to the other side....they should feel the same.Best regards Roland GTT

[beatbox]

FAILED ITS MOT at 15000 Miles!!! But if you just jack up the wheels and feel for any play. My offside wheel had that much play it was scary !!!

[johnmdanskin]

Quote: Originally Posted by MarkW19 (original)

...Why do you suggest fitting the stock anti roll bars back on? Shouldn't the Eibach bars give an improvement? And, shouldn't the lower the car is (within reason), the better it handles (lower centre of gravity etc.)? I'll get all the front suspension components checked out, and tracking checked etc. Really don't want to go back to 17's though...but I did also have this problem with my 17" bullets briefly, before I got the 18's. Also, the KW v2's were fantastic on my Cooper, so I wouldn't think it's the actual product - just probably a set up issue somewhere?...

Sway bars change handling. Bolting a bunch of handling changes to the car doesn't make handling better. It makes handling different. Each change should be for a specific reason, not just to add more stuff.

Bigger sway bars (or stiffer settings on the same sway bars) do two things:

1. Reduce traction at whichever end you are adding swaybar to.
2. Make the car flatter, mostly at that end, which can help with tire-roll

In a mini used on the track, starting from stock, you typically want more traction in front or less traction in back or both. This moves you from understeer to oversteer. Oversteer is less safe for novice and intermediate drivers. Oversteer allows faster cornering. Where you want to be in this continuum is up to you, but I advise making one change at a time and moving slowly or you could be surprised.

From what you are saying, your car understeers. Here are some things you can do to adjust this balance.

1. back to the stock front sway bar. this will add traction in front, which is pretty much just a good thing.
2. harder settings in back, removing traction at the back. this is only good if you are prepared to deal with more oversteer. Again, when you dial out understeer, you are dialing in oversteer. One change at a time, small changes, test your car gently after each change until you understand what you have done.
3. more negative camber in front. (camber plates) I am up to -2.75 degrees in front. This adds grip in corners at the expense of accelerate when the car is flat (and cornering if you don't have an LSD), and braking. It also reduces front tire roll, which is my main concern after using up a set of michelin PS2s in 2.5 track days per pair (almost $200/day, yikes).
4. Softer springs in front, harder springs in back. Same as swaybar. Softer in front adds traction and improves ride, but might give too much flex in corners.

Lowering will have added some camber at both ends. More ultimate traction, not obvious what this did to your balance.

In general, 17" wheel/tire combinations will have more grip as well as a better ride. My car came with 18s, but I'm not using them on the track. Also, more tires available, especially in high performance. 18s are nice if looks are more important than performance. Lots of people go to 16s for track applications.

[MarkW19]

Thanks for all the help guys, and john: some great tips there. I think the first thing to do may be to revert back to the stock front anti-roll bar then. I'll also experiment with the KW's "stiffness" setting, and try fairly stiff on the back (maybe 65% stiff), and softer on the fronts (starting at 35% stiff, the fronts are loads easier to change so I can constantly experiment with these). As it stands, the rears are quite soft (20%) and playing with the fronts doesn't really seem to change much.

I'll also keep the rear anti-roll bar on it's softer setting, otherwise I fear of too much oversteer (which I don't want).

I'll also play with tyre pressures - 32(front) and 30(rear) as Roland recommends.

I love my wheels (OEM GP 18"), so will be keeping these (with the Eagle F1s). I don't do any track days, all I'm interested in is getting better overall handling. I don't push it that hard at all - but currently it just feels all over the place.

Think I'll take a trip down to Lohen and spend the day with them, making various adjustments and see what happens.

The harshness/crashiness of the ride is another matter - again, I want to keep my 18" wheels...maybe switching to Koni FSDs would significantly improve things, but I really couldn't go back to having my car higher again (and using lowering springs with the FSDs will severely decrease their benefit).

I'm sure I'll get to the bottom of this sometime soon, it is driving me a little mad.

[johnmdanskin]

stock sway will help with the crashiness. front shocks all the way soft.

you can go down or up on tire pressure. on the track I started at 40 all around, and was going up in back to try to dial out oversteer. The pyrometer said I was pretty close in front, and I wanted pressures high to try to reduce tire-roll again. On the street, I'd consider stock front setting and then raising rear pressure a few pounds over stock. The idea is to dial front in for max traction and then move rear away from max traction until the car is where you want it. Don't go too low at either end. Anything less than about 27 is probably not a good idea.

the other thing you need to realize is that the car will be a lot more touchy with your stiffer suspension. Stiff suspension removes grip and increases sensitivity to your input: You will need to be a lot more gentle and progressive in all of your inputs. The upside is that the suspension geometry doesn't move around as much which makes the car easier to steer. If the front end is bouncing up and down while you are cornering at the limit, it can be hard to keep the stress on the outside front tire constant.

Colin Chapman sprung his lotuses very soft for grip. This worked well in very light cars. Relative to competition lotuses, the mini is heavy, but relative to other cars on the street, the mini is very light. Minis can benefit from softer suspension than most other street cars.

[MarkW19]

Thanks for the advice.

Any suggestions re. the steering - in my Cooper it was nice and heavy/tight with lots of feedback...in contrast, in the Works it's light, takes quite a bit of movement before much happens, it feels sloppy. The only difference is I now have 5mm front wheelspacers.

[Damo]

Having got the same eibach anti roll bars, 18" wheels and eibach loweting springs with worn out shocks (40k with eibachs so far) all I can say is the handling is immense.

Got to agree with most people here though, if its understeering, then you either stiffen the rear or soften the front.

I'd personally go for the easy fix of putting the rear bar on a stiffer setting as you could do this yourself. But that would cure the symptons not necessarily the problem.

I'll let you know what mines like with V3's (If i can ever afford them)

[roland2003]

....Hi, assuming no knackered joints,then excessive toe out is quite likely the culprit. Nervous handling is a descriptive term for oversteer rather than understeer which tends to feel safe.
Toe out will dart the car left then right on as weight shifts even going straight if the road isnt flat.
R compound tyres such as R888 have a recommended (cold) pressure for a car the weight of a Mini of 23-27psi. Thats what we run and works the best. A normal 'list 1A ' tyre maybe 5psi more.
Best Regards Roland GTT