We at Mini Mania have been very satisfied with our experience of being able to help almost any Mini Cooper owners when asked the question ‘How do I make it better’. With our 30+ years of owning and racing Minis we think we have done almost anything you can imagine. We have built restoration and show cars winning both professional and amateur show events. We have built and raced class champion Autocross Mini Coopers. Our converted hydro-lastic Mini Cooper S was ‘the car to beat’ in the California autocross world of 20 years ago. Our Vintage Race Mini Cooper has not only been on the tract for 20+ years, it has proven a fantastic tool for sharing the experience with several of our staff. And our Land Speed Record Mini Cooper still holds the record at the Great Salt Lakes as being the fastest Mini Cooper on record. You would think that with all this vast experience that we could simply rest on our many trophies and relax in the knowledge that we had ‘been there, done that’. BUT with the influx of so many later model Minis into the USA in the last couple years, we have had to stop and actually start to think again on the best ways to be able to answer the question ‘How do I make my Late model Mini Cooper better’?
For many years in the business many of us considered ‘late model’ meant that the Mini was probably a MK3 or so. WOW! What a change we have had to go through, the normal ‘late’ model Mini Cooper today was built in the ‘90s.
So what are your choices? You have this car because you probably looking for a nice reliable Classic Mini? The first basic question has to do with expectations and intended use? If you have only had the car a short time (typical) what are your plans. More pleasure in driving? Are you looking to ‘personalize’ the car? More Horsepower?
Where to begin? The first consideration is to realize that while you Mini Cooper is a late model and thus has probably not seen many individual owners, it does not mean that it is still as delivered from the factory. The history of the Mini is that it is most often changed by each owner in some way or another. The shear fact that you are considering some sort of change or upgrade is only typical of all Mini owners. It should be understood upfront that the late model Minis don’t lend themselves well to upgrades as they have had the benefits of the evolution of the model through out the years and have seen many past upgrades that were made standard by the factory.
The use of disc brakes is universal on all of the late cars and thus no real need for any sort of change. The only option you have there is to consider a brake pad upgrade. Pad technology has evolved so much over the year that a upgrade here is a real possibility. The best example I can offer n this are is in reference to the original “S” 7.5” brakes. Back in the ‘old days’ we often spoke of ‘upgrading’ the brake of the “S” to either 4 pot or alloy calipers or even converting to the later 8.4” setups. The truth of the matter is that with today’s brake pad technology- you can get extremely good 7.5” brakes with nothing more that the right choice of rotors and pads. And while you could upgrade the brakes of the late model Mini Cooper from the stock 8.4” rotors and caliper to ‘vented’ rotors or alloy calipers, etc., etc. any of these are real overkill on a street car! Pick a up-rated pad and you will achieve 80% of the possible gain at less than 20% of cost of other upgrades.
“How to improve your driving pleasure”? in a Mini typically means how to get yet better handling from your ride. Now in this area your late model Mini Cooper has seen the good and bad of the evolution of the marque. The Mini Cooper has always been renowned for great handling and in the early days it typically meant ‘no compromise’ handling. Comfort was secondary to the average owner and as the factory knew that there was not any real effort to make the car comfortable to drive. But that all changed over the years and the late Mini today now has a least 12” wheels and in many cases 13” ones. This again is little confusing as in the old days it was considered an upgrade to go to 13” wheels with wide tires and then that was when the car was lowered and had sway bars, etc. The factory version of this upgrade resulted in not only a narrow tire (typically a 145/70 but they also actually raised the car up to be sure to get enough travel and road clearance. So while the upgraded to 13” wheels, they compromised on handling for the sake of comfort. Not only is a tall 13” tire very compliant and thus softer riding, when you have a narrow tire it is more relaxing to drive. So what should you do- the easy answer is to simply put a set of 165/60 series tires even on the stock rims which are typically a mag wheel of some sort. If you want to go to the next step I then consider going to a 5.5 or 6” wide rim. But on this front I would add a word of caution. The Mini Cooper is only a 10’ long vehicle and as you widen it’s wheel track it will indeed go around a corner better but will actually be more uncomfortable in a straight line. It will actually have a tendency to be ‘darty’ on freeway etc. as it you hit concrete seams and other road anomalies. It for sure will be a trade off- better handling but less comfort.
The next most obvious step is to lower the car and add a rear sway bar. Even the early generation of the Mini Cooper was designed to have understeeer or push. It is a well know fact that automobile manufacturers believe that the average driver is not very competent and thus it is safer to give them a car that understeers rather than oversteers. This could be a foreign language so a very short explanation might be in order. There have been books written on suspension understanding and tuning but this is not the time and place to go into that level of detail. It is sufficient to understand that a car is ‘pushing’ or has understeer when it fails to rotate in the same proportion as the steering wheel is turned. This it has a tendency to go in a straighter line that you intend with the position of your steering wheel. A car oversteers or is ‘tail happy’ when the turning radius become much smaller than intended. The rear of the car turns faster than the front or in worst case conditions; the rear of the car tries to pass the front of the car! As a Mini Cooper is a front wheel drive car it has a number of advantages when it comes to handling, not the least of which is the fact that it is ‘pulling’ the car through the corner rather than trying to push it. This fact alone accounts for fact that it can be driven very hard even if the set-up of the car results in some amount of oversteer. Many of us have seen the vintage pictures of a Mini Cooper on a road rally going sideways through a turn! This is taking it to an extreme and is not recommended for a daily driving routine! But adding a ‘tendency’ for oversteer to a Mini Cooper is one of the bigger improvements you can make. The simple addition of a rear sway car will increase your feeling that the car is turning quicker. I will not try to go into what all this means at this time (perhaps in another article I will go into ‘trailing throttle oversteer and why adding a rear sway bar is affecting the front of the car).
If ride comfort is high on your list of objective for upgrades I would suggest you consider both shocks and springs. The stock shock is a good choice for comfort but also has a shorter life span that a performance version. But the down side of a performance shock is that most of them, even the adjustable version is have a stiffer ride than stock and thus in many peoples mind, not as comfortable. A worn out stock shock is also not comfortable, thus for comfort- replace the stock shocks with new stock shocks.
The main suspension spring in the Mini Cooper is another long subject. Most Minis still use the original suspension design that used a rubber cones as the spring medium. Not only was this unique and revolutionary in it’s design but it’s compact performance was unequaled. It has evolved that upgrading from stock rubber to modern coil springs is common among and early classic Mini owners. But it is important to understand that the early Mini owner had a different motivation that those of you with late model cars. The primary issue for the early cars is that the rubber cone does age over the years and not only gets hard but also sags and thus there is great benefit in at least installing new rubber cones. I this case it makes good sense to at least consider an upgrade to the coil springs. The primary benefit from this upgrade is ride comfort. The ride is far less harsh, it is just plain more comfortable. The trade-off is handling. The coils set-up can also be made to actually improve handling but ‘requires’ the use of at least a rear sway bar and in many cases a front also. The coil springs will also typically raise the ride height of the car. This is again a good thing for comfort but the use of a adjustable ride height system such as Hi/Lo set-up is a must for improved handling.
As I had intended to make this a very short summary on the various things that could be done to upgrade your late model Mini Cooper it has now become very clear that I can not make it short. I have already exceeded my space and have yet to get into horsepower upgrades. I will save this for the next chapter of the story.