MINI Cooper S R56 – Ultimate Handling
We often get asked about what can be done to improve the handling of the MINI Cooper. Its already a great handling car…no question. But, if you want to take it further, how far we go all depends on your objective. But, if you really want to go all out, and have one of the best handling MINIs, and have a larger budget than most, then this is the approach.
The constraining factor on the MINI Cooper suspension changes (whether its the R53, R56, or even the newer F56), is the limitation in the front suspension “travel”. There is very little total amount of suspension travel given the suspension design and geometry. So, if you are thinking of doing either sport springs or coil-overs, most of the time this will lower the ride height (better looks, lower center of gravity, lower CG, lower roll center), but it comes at a loss of suspension travel. The loss of suspension travel means when the front suspension is compressed, it will encounter the bump stops earlier. This produces a harsh ride for normal street driving. For track use, its not really an issue as much. So, we try to manage the limited suspension travel, and make the best of a not so great situation. (And, that’s one of the reasons why just doing sport springs is not a wise choice, and will produce a ride that feels like the car is riding on bricks).
This customer was willing to accept the slightly harder street ride, for an optimized track suspension. Therefore, that moves the decison towards true “coil-overs”. We still hold true and hard to our concern / requirement, that if you are going to have “coil-overs”, then we want them to be adjustable (to allow and support the dual duty implementation, and to allow the ride / use to be tailored to the users needs)…..and therefore, if they are going to be adjustable, it needs to be easy to do, something that can be done in less than 5 mins. While that would seem like a logical requirement, almost all after market “coil-overs” hide the adjustment knob up inside the body, and eliminate the ability to tune the car to its use. For this project / selection, that leaves us with solutions like Bilstein PSS9, KW v3 or KW Club Sport, or AST. AST is at the top of the pyramid of these options (and also more expensive), and thats what this customer choose to go with. Besides being more expensive, the AST offers the “inverted” strut design, to help eliminate “stiction” under cornering loads, and also is better matched in shock valving to the higher rate race springs. Choosing AST versus the Bilstein PSS9 or KW v3 means we can also selected what springs / spring rates we choose, and we selected SWIFT springs (slighlty lighter, more travel before going into spring bind).
When doing a full suspension upgrade, it incorporates the normal subjects: front coil-overs (AST single adjustable), front upper adjustable camber plates (Vorschlag), front lower control arm bushings (Powerflex), rear adjustable sway bar (Alta 21mm size for the R56, 19mm size for the R53), rear coil-overs (AST single adjustable, w solid upper shock mounts), rear sway bar adjustable end links (Alta), adjustable rear lower control arms (Alta).
Other good options would be the NM Engineering adjustable rear sway bar. But, don’t the mistake on sway bars of thinking that bigger is better…anything larger than the 21mm on the R56 will make the rear end feel twitchy, not confidence inspiring when driving the car hard, even on the street.
Rear adjustable lower control arms – allows for more camber adjustment, for alignment, and is also much stronger than the stock weak lower control arms. (see lower control arms in picture above, and new adjustable control arms below). You can also see the ease of shock adjustment w the AST (gold adjustment knob on the bottom of the rear shock, see also the pic below this).
The other standard element to upgrade on the MINI….any MINI, is the front lower control arm bushings. The stock ones are soft, rubber, have too much flex, and wear out too soon. The standard that we use is to upgrade the front lower control arm bushings to Powerflex polyurethane. You can select between two durameters of the poly, but we always go with the “purple” version, which is better for combined street and track use. The other side benefit of the Powerflex bushings is that they offer a lifetime warranty…a nice thing to have when doing upgrades.
The final piece is brakes…and this is more guided by budget….the stock brakes are horrible…and will not do for track use at all. You can try all the little band-aid approaches (ss lines, brake fluid, different rotors, different pads)….and the brakes are still horrible. In fact, some of the band-aid approaches make the braking worse…as higher co-efficient of friction brake pads will generate more heat, and heat is the enemy here.
The two proven options are: MINI JCW (John Cooper Works) brake system upgrade, or a true “big brake kit” (BBK). Often the decidiing criteria has to do with wheels….the JCW upgrade will fit inside MINI 17″ wheels, whereas the BBK’s “may” NOT fit inside a MINI 17″ wheel, and often require an upgrade to 18″ wheels.
For this customer, we went w the JCW upgrade option, as we needed to be able to fit inside the existing MINI 17″ wheels. You can do the JCW upgrade to the front only, or front and rear, and we did both on this car.
If you are thinking of a true BBK, then for us, there are only two options, either Brembo or StopTech. From a price point of view, we often get asked about Wilwood…but, we have had bad luck w WilWood every time a customer has wanted to go that route….they hold good promise, but fail to deliver.
ENGINE / EXHAUST
For this customer, at this stage, it was all about handling. So, no upgrades to the engine, downpipe, tune, blow off valve, or exhaust.
Completed car….happy customer.
BRracing – What can we build for you?
Can you tell me if easy to do and hw mutch
Thank you for this interesting post, I have shared it on Facebook.