A Shopping List of Basic Improvements for the MINI Cooper

One of the great things about the MINI Cooper is the robust nature of the basic engine. It is capable of producing much more power than it does right out of the showroom, even with the supercharger. There are some good reasons why it doesn’t.

For one thing, an engine that produces better performance costs more money. Materials used in a high-performance engine are better and the engine is assembled with greater care, both of which add costs.

However, most people really don’t care enough about performance to want to pay the extra price. Also, with higher horsepower, the engine doesn’t produce as many miles per gallon, and is more difficult to tune to meet emission limitations, so the product designers, even in the MINI, simply had to make some compromises.

But you don’t have to compromise. Aftermarket suppliers (the companies that make products that are bought by owners after the car is bought from the dealer) have developed a number of products that will allow you to improve the engine performance in your MINI to get better pick-up, higher speed, and simply more driving satisfaction under all speeds and situations.

If we think about that basic air/fuel/spark/exhaust equation, we want to do four things. We want to increase the amount of air entering the supercharger and we want to increase the compression capability of the supercharger, both to get more air into the combustion chambers. Then, we want to have the ECU take advantage of that added air flow to by altering the fuel mixture and timing for performance efficiency, and we want to make sure that all the smoke from the combustion can get out of the combustion chambers quickly.

We can make those improvements by upgrading the throttle intake and supercharger pulley, reprogramming the ECU, and upgrading the exhaust system. Since each of these components operates as part of the overall internal combustion cycle, you’ll get the best performance from each if you upgrade them all at once.

However, if you can’t do that, you can upgrade these components in any order that appeals to you and you’ll still notice the improvement that each component contributes to overall engine performance. And when you’re done, you’ll really have an engine you can brag about. We’ll discuss the upgrades in the order that they occur in the operation of the engine and describe the upgrades you should consider.

Mini Cooper Cold Air Intake System

Before we can have combustion, we have to have air. If we can increase the amount of air flowing into the supercharger intake, and keep it as cool as possible, then we’ll be helping the supercharger do its job by giving it more air to breath.

We can do this by replacing the standard air intake system with an upgraded “Mini Cooper Cold air intake system.” The standard cold air intake system in the MINI is really not all that complicated. Air flowing into the engine compartment through the grille is channeled into an air intake box on the top of the engine. In the box an air filter removes dust and dirt that would create undesirable wear in the engine. From the air intake box, a duct directs the filtered air into the supercharger. In addition to capturing and filtering the air, the ducts on the standard air intake system have been tuned, like you might tune an organ pipe, so that the air flowing through it produces as little noise as possible.

The standard Mini Cooper cold air intake system easily can be swapped for an upgraded one that has been designed with performance in mind. Several aftermarket equipment manufacturers make replacement cold air intake systems for the MINI, but we’ll describe two typical designs.

The simplest way to improve the system is to replace the stock air filter and air intake box with a higher-quality filter that has been designed specifically to increase air flow while still providing the same filtering functions. K&N makes a high quality filter that is used in combination with high-velocity ducts in several of these kits to replace the basic system. Since it can be cleaned and re-used, we don’t have to buy a new filter every time the old one gets dirty.

An alternative approach that not only improves filter performance, but also provides additional air flow into the intake is now being manufactured by several companies. In this system, the entire air intake box and filter is removed and replaced by a conical filter surrounded by an L-shaped divider. This system helps increase power not only by improving filter efficiency, but also by increasing the flow of air into the system.

This system is designed to do a more efficient job of directing the air from the front Mini Cooper grille into the engine’s air intake. In addition, by being open at the top and back, it captures air from the grilles below the windshield, which are in an area of the body where air flow creates high pressure. By ducting some of that air into the supercharger in addition to the air coming in through the grille, the system naturally allows more air to enter the supercharger intake.

To make sure there is as little as possible to obstruct the air flow once it gets into the air box, the cold air intake system incorporates a reusable high-flow cone-shaped air filter. K&N’s popular re-usable high-performance filters are frequently used in this application. The design of the upgraded cold air intake system offers one other advantage. While providing a direct path for air from outside the car to flow into the supercharger, it blocks off the hot air swirling around the engine. As we learned in science class, hot air is thinner than cold air, so the cooler the air going into the supercharger, the more efficiently the supercharger can do its job.

Though generally similar in design, these systems do vary somewhat from supplier to supplier. Two features should be considered when deciding which one to buy. First, the best dividers are made of shiny stainless steel. As a result they will reflect engine heat back to the outside of the box, so the cool air coming in from outside the car doesn’t get heated up before being pulled into the supercharger. Second, the divider should have good space all the way around, so that air can flow into the entire surface of the filter without any restrictions.

A typical cost for the parts for an upgraded Mini Cooper cold air intake system is about $200. The design is simple, and can be installed by anyone with the instruction sheet and the proper wrenches in a few hours or less. If it is done in a MINI service shop, it shouldn’t take more than half an hour of shop time.

If you own a Cooper model, you can still make improvements in air flow into the engine. A less-restrictive reusable flat filter is available for about $50 to replace the stock filter. Aftermarket developers have also re-engineered the ram air intake duct and air box cover to improve air flow. Installing this improved ducting system in conjunction with a reusable high-performance flat filter will cost about $200 and make a measurable improvement in your Cooper’s horsepower.

The Basics of Internal Combustion in the MINI Cooper

Let’s start at the beginning. Your MINI Cooper is powered by an internal combustion engine. Aside from some electric cars, nearly all cars on the road have IC engines. All this means is that the power is produced by an explosion—combustion— that happens inside—internal to—the engine.

In contrast, in an electric car the combustion happened somewhere else, at a power plant or in the sun. The resulting energy was sent over the electric power grid to be stored in the car’s battery and then used by the car’s motor to produce power.

With a hybrid car, the power still comes from internal combustion within the car’s engine. However, what makes the car a hybrid is that it also has an electric motor that can be used as both to produce power and to generate power. Normally the car is driven by the IC engine, and any excess power is used to make the electric motor generate electricity, which can be stored and used by itself, or in conjunction with the IC engine. But we digress.

In an internal combustion engine, the power is produced by the interaction of three forces. Air is pulled into the engine, is mixed with gasoline, and then the mixture is compressed by the cylinder and ignited by a spark to produce an explosion which pushes the cylinder down, turning the crank, and producing power. Air, fuel, and spark. Once the explosion occurs, the only remaining task is to get the resulting smoke out of the engine as quickly and efficiently as possible, so a fourth factor, the exhaust, enters the equation.

In modern automobiles, to provide the fine-tuning needed to maintain performance while meeting emission regulations, the air/fuel/spark equation is controlled by an engine control unit (an ECU)—a computer which controls basic engine operations like fuel mixture and spark timing— linked electronically to the throttle pedal and to several sensors that measure engine performance.

The S Stands for Supercharger

In the MINI Cooper S, the engineers added another component, the Mini Cooper Supercharger, which is only used on high-performance cars. It is used on Jaguars and Bentleys, for example, but on few cars as inexpensive as the MINI. The presence of the supercharger is one of the few major differences between the MINI Cooper and the MINI Cooper S

The supercharger is worth a few words on its own. As we mentioned, in order for the fuel to burn, we need air. If we want more powerful combustion, then we need more air.

This principle first became an issue back in the days when all airplanes used IC engines and the designers wanted their craft to fly higher. However, the higher the airplanes flew, the thinner the air became. With less air, there was less power produced by the engine. So engineers came up with the idea of using a little component with spinning blades, powered off the engine, to compress the air coming into the engine. With more air being forced into the engine, more power could be produced. They called it “supercharging” the engine.

It wasn’t long before automobile designers were using the same invention on the ground to make race engines run faster without having to get bigger. Remember the “Blower Bentleys” that were raced at LeMans in the early 1930s? You probably don’t, unless you’re an auto history buff. They were probably the earliest well-known application of a supercharger in a racing car. But if you want to impress your car buff friends, just tell them you have a “blown” MINI and refer to your supercharger as the “blower.”

It’s that same principle we find in the MINI Cooper S today. A small turbine between the air intake and the engine is driven off the main driveshaft by a pulley and belt to compress air coming into the engine. More air means that more fuel can be added, and more power will be produced.

Incidentally, engines in some other makes of cars address the same problem of compressing the intake air by using turbochargers. The difference between a supercharger and a turbocharger is how the little vanes in the turbine are powered. In a supercharger, the power comes directly off the driveshaft, connected to the supercharger pulley by the main engine belt. In a turbocharger, there are two sets of vanes, connected by a shaft. Exhaust gas coming out of the engine spins one set of vanes, which in turn push the other vanes that push air into the engine.

The problem with a turbocharger is that you’ve got to wait for the engine to build up some exhaust pressure before the turbo kicks in—what the gearheads call “turbo lag”—which means that the added power isn’t immediately available. With a supercharged engine, the supercharger spins faster as the engine gains speed, so the added power is always on tap and ready for use.

Improving Your MINI Cooper

You’ve probably already been impressed by how good the MINI Cooper is at what it does. It’s quick off the mark, fast on the highway, and can zip around corners at an enviable clip with almost no body sway or looseness.

What’s to Improve?

To be more specific, the stock MINI Cooper S can get from zero to 60 in just under seven seconds, which puts it easily in the middle of the pack of what are called “performance cars.” Top speed is north of 130 miles an hour, which also makes the car quite respectable in the sports car league. That speed is much faster than most of us should be driving, even on a closed course, though it does mean that at normal highway speeds the engine is right in the middle of its power band with lots of reserve power when needed.

Cornering is where the car really excels. BMW has a well-deserved reputation for suspension engineering, and it is really reflected in this car. Compared to even the best of the performance cars, this car chews up corners without looking back, leaving most of the rest of the pack at its rear.

However, there are still areas where the MINI’s performance can be improved. That’s not surprising, of course, since the design and development of a modern car is a balancing act. A wide variety of vehicle specifications are affected by laws and regulations. Fuel economy, smog emissions, and crashworthiness requirements all challenge designers by adding weight and putting limits on engine performance.

Designers also have the problem of deciding what the market actually wants in a car. Most auto journalists and some potential customers want a car to be fast off the mark, capable of high speeds, and able to corner without body sway. At the same time other buyers simply want a car that is quiet, comfortable, and smooth-riding.

And all of this regulation-following and customer-pleasing has to be put together into a car at a price that will be competitive in the marketplace and still produce a reasonable profit. So automobile designers and engineers have to make compromises.

The great thing about the MINI is that the basic platform is well-designed and very well put together. So once you’ve decided what kind of a MINI owner you want to be, you can make the changes you want so that your car won’t be just some product planner’s package of compromises. And with some knowledge and care, you can make your changes without having any bad effects on the overall quality and reliability of the car.

So if you will all take your seats, we’ll start the first class in “Maximizing Your MINI 101.” In this first class, we’re going to focus on the principles of making the MINI make more power. We can do that because the steering, handling, and braking are all well above average, so we can save those factors for a later class.

Join Your Many MINI Friends

Sure your MINI will be great for all the normal stuff, getting to work and out in the evenings, transporting you and your luggage on trips, or moving furniture, plants, or whatever else has to be moved from one place to another on the weekends. But there’s no substitute for just taking the car out on a weekend for the sheer pleasure of driving.

If you can combine that with some friendly comaraderie, all the better. And there is where the MINI will excel. When Minis were first introduced in the sixties, their owners immediately recognized that they were a special group of people, able to appreciate the finer things in automobiling, and Mini clubs rapidly grew up all over the world.

Those clubs remained active throughout the dark years when Minis weren’t even sold in the United States, and were a ready-made network of friendship and support when the new MINIs were first introduced. Recognizing the common appeal of old and new Minis, the club members were among the first to line up to try and buy the new MINIs, and the clubs welcomed the new owners with open arms.

Today, any assembly of club members will still include a few of the old classics, but the majority of the members will be driving new MINIs. It’s easy to become one of those members.

All clubs arrange frequent tours to allow members to get their cars out on the good roads in their areas, as well as organizing social and charitable activities around their cars. You’ll be surprised at how many activities are available.

You’ll also probably be surprised at the wide range of backgrounds and interests represented by people who have been drawn together by the attraction of this new car. Membership in most of these clubs will span every age, from new drivers to old veterans, and their day jobs will cover every occupation and endeavor.

The nice thing is that, regardless of how much different the members are from one another, you’ll all have one common interest in your MINI, which means there will always be something to talk about as you get to know one another. As one member said recently, “I was surprised at how many friends I had that I hadn’t even met yet.”

In the appendix to this book, we’ve listed the contacts for as many of the clubs as we could find at press time. For current information, check with your local MINI dealer, who will know if there is a MINI club in your area, and it won’t take you long with an internet browser to find a current list of clubs.

If you can’t find a local MINI club, maybe now is the time for you to start one. It won’t take much effort. Find a local restaurant or pizza parlor with a back room you can reserve, make up some flyers announcing a meeting in a month or so, then stick them on any MINIs you see. Offer to work with your MINI dealer to start a club. In no time, you can have your own local club.

Take a Course in MINI Motoring

Once you’ve read the manual thoroughly, and become an expert on your own car (just try not to bore your MINI-less friends with your new-found knowledge and enthusiasm) and you’ve been around the block a few times with the car, it’s time to get serious about really learning to drive.
First, we want you to go back to school. Yes, we know you’ve been through that driver training school before you got your license, and some of you might even have already had the experience of taking one of those state-administered driving schools that are offered with the first traffic ticket. Trust us; they didn’t even scratch the surface.
When you were driving that little driving school car around your town, did you ever stomp on the brakes hard enough to make the anti-lock braking system kick in? Did you ever take a turn fast enough to make the tires squeal? Did you ever get the car to skid? Intentionally? If you haven’t done all of these things, you haven’t begun to learn to really drive.
When you’ve had the chance to learn these things and practice them, the difference will be that when things do go wrong, you’ll be able to be a real driver, not just another potential crash dummy or organ donor behind the steering wheel.
What we’re talking about is a real driving school, like professional race drivers take when they first start to learn to drive fast. We’re talking about taking the car out on a driving course or race track so you can find out what happens when something unexpected happens. We’re talking about learning what you should do when things do go wrong, so you can make them go right again.
Lest you assume that you only need to go to an advanced driving school if you’re thinking about racing, let us be very clear. Participating in one of these schools will return every penny it costs and every minute it takes will make you a better, safer driver even if you never put a wheel on a track or autocross course again in your life.
In several studies comparing high school students who have taken advanced driving courses to a random sample of those who didn’t, the rate of accidents was shown to be significantly reduced. Most insurance companies even give a discount to young drivers who have completed one of these schools. And if these penny-pinchers see the dollars and sense value of advanced driving schools, then you can make up your mind that value exists.
There are lots of different opportunities to learn to drive better. Start by checking with your MINI dealer, since some of them sponsor MINI driving schools, or will be aware of courses in the local area. Check with the websites listed in the back of this book for driving schools sponsored by or in conjunction with the suppliers of aftermarket parts for the MINI.
If there is a auto-racing track near you, check with them as well, since most race tracks host driving schools. The best situation is one where you can drive your own car in the course. One basic driving courses where you can use your own car is available at Thunderhill Park near Willows in north-central California (www.thunderhill.com).
At least one driving course has been designed specifically for BMW MINI drivers, developed and presented by the Phil Wicks Driving Academy. Information is available at www.Minidriving.com.
In this book, we’ll be passing on many of the tips that these courses offer their students, but nothing substitutes for the experience of taking a good driving course in your own MINI to put those tips into practice.

Getting to Know Your New Best Friend

Right off the mark, two things are good about MINIs. First, they’re already among the best sports cars on the road in terms of their ability to go fast, corner fast, and stop fast. Second, like other cars that are just plain fun to drive, MINIs have the uncanny ability to gather people together into clubs and organizations that have the sole intent of helping their members enjoy driving their cars.

Combine these two factors, and you have a recipe for easy weekend fun: a good car to drive and a like-minded group of friends to drive it with. Our first recommendation is to get to know the car well so you’ll know how much fun it can be. Our second recommendation is to join a Mini club so you’ll have excuses to have fun with it as soon as possible.

We’re even going to recommend that you not make any changes in the car immediately. Why spend money improving the car until you’ve got a benchmark to which you can compare it? With a clear memory of what your car was like before the improvement, when you do make changes in the car you’ll be the first to notice and appreciate the difference.

The MINI has been designed by enthusiasts with enthusiasts in mind. What we want to do is show you the difference between simply operating an automobile as a means of transportation, and driving a performance car for the sheer pleasure of it. But where should you start?

We’re Serious: Read the Manual

We’re going to assume that when you first considered buying a MINI and visited the dealer, the sales rep spent a few minutes showing you the good features before you went out on a test driver, and told you more about how and why things are designed the way they are.

We’re going to hope that you allowed a little time and curbed your enthusiasm when you first picked your car up to listen again as the rep talked you through the main controls and features. However, we’re going to bet you weren’t paying much attention. Sitting in your very own brand-new car is just too overwhelming an experience.

So now that you’ve been driving your new MINI for at least a few days, what should you do? Start with the owner’s manual. We’ll bet that you’ve never read the owner’s manual from beginning to end for any car you’ve ever owned. Too bad. There’s a lot of information in those manuals so that from the beginning you’ll feel confident that you understand your car.

The best way to do that is to take an afternoon in your driveway and sit in the car. As you read each section, look at the diagrams and compare them with the way things actually look in your car. Move, adjust, push, pull, try each of the levers and buttons. Don’t just look at the top of the oil dipstick, for example. Take it out and see what real oil looks like. Take the radiator fill cap off and look inside to see where the level should be.

In other words, get to know the car thoroughly. Learn about it as if your life depended on knowing the car. Some dark night, it very well might.

If you don’t have time to read the owner’s manual all the way through right now, then put it in the bathroom. Owner’s manuals are great reading material for those few minutes when you really don’t have anything else to do. Every time you have a chance, read a section, and then when you go out to your car the next time, try to remember what you just read and check out how it looks in real life.

Another tip: when you’re driving your car, try to be as aware as possible about what it does and how it does it. Try to feel how the car moves and sounds when you accelerate, when you take your foot off the gas pedal, and when you put on the brakes. Try to feel what the car is doing when you turn a corner. Turn off your Ipod once in awhile and listen for the sounds of the engine as you accelerate and shift gears. Those feelings will be important as you start to plan how you want to improve your MINI and when you work on improving your driving.

MINIs for Streets and Roads

When the original Minis were first introduced, they were intended simply to be used by regular drivers on regular streets and roads. Nevertheless, with a few upgrades by John Cooper, they proved to be great on the long-distance European road rallies such as the Monte Carlo and Alpine rallies where they first made their fame.

In SCCA club racing and later in vintage racing events in North America, they showed their ability to wag their tails at the opposition and then run away and hide until they took first at the checkered flag. They were also very successful in European saloon racing (which isn’t racing around liquor bars, as you might expect, but the continental term for sedan racing).

But classic Minis became popular mostly because they were so darned easy to drive fast, and because they could go so many places and do so many things better than bigger, more powerful cars.

The new MINIs are stamped from the same mold, fun and practical at the same time. Right out of the showroom, they’re able to do the everyday stuff well, and still bring a smile to your face every time you take one around a corner quickly or pass a pokey car on the highway.

But we’re here to tell you that you can tweak your MINI just a little bit and make it even better, making your driving around the neighborhood or around the countryside even more fun. With a little professional instruction and some opportunity for practice, you can also learn to drive it better than you’ve ever driven another car.