The BMW M Coupe - what a wild ride! I've owned one since April 1999 and I've loved every minute of driving this car. The styling is extremely individual, and unmistakably aggresive. It's compact dimensions and functional nature call attention to the fact that this is a drivers car. It's wide rear haunches aren't there to show off, they're there to accommodate big tyres. The aggressive looking front air dam is there to cool the breaks and engine, and the large wheels give the car excellent lateral rigidity.

The car is incredibly nimble, and has awesome cornering. I regularly lap the car around Seattle International Raceway, which is the only way to appreciate the true capabilities of the M coupe. Endless acceleration is matched only by fierce, fade-free breaking, and kart-like cornering. I was mesmorised by the snarl of the engine as I changed down through corners and exited on full throttle. Simply sensational.

Sitting in the cockpit you feel like an F1 driver. The instrument panel is a small round-top cluster of guages and the wheel is quite high up. You sit at the same height as the engine, instead of above it, and you're a couple of feet from the quad exhausts that bark and growl as the engine warms up. There's no mistaking that this car begs to be driven very fast.

But like most great things, there was still room for improvement. I have made extensive modifications to my Coupe. The first was to fit Koni shocks and springs by way of Dinan's stage one suspensions setup. The major criticism I had was that the car squatted too much on acceleration, and the stiffer Koni setup really helped that. It also reduced body roll in corners (which was already very insignificant). The ride is a little harsher, but this was an excellent enhancement to the car - money well spent.

Recently I decided to upgrade the engine with Dinan's Stage 2 supercharger. A couple of days work on the car yeilded 360bhp and 310lb/ft. The new torque curve perfectly matches the old, but with a significant hike! Acceleration must be felt to be believed, where it was fierce and sustained, it is now brutal and destructive. Part of the work Dinan did was to fit a Triflow quad tipped exhaust. This is a superb exhaust system, finally the car has the bark to back up its bite!

Six months later, I made the advance to Dinan's stage 2 suspension and lightweight flywheel setup. The anti-roll bars have reduced understeer to almost zero and have really flattened the car in corners. The stage 2 clutch and flywheel were necessary to cope with the additional torque and also make the car much smoother to drive. While the car was in the shop, I got them to install the floating rotors from the euro-M3 in front, which provide for better cooling and less fade on the track.

Here are some pics of the original Dinan superchargersetup:

Engine bay with supercharger assembly	Close up of Vortech supercharger

In what will likely be my final engine modification, I had RMS cooling kit installed. This includes the "aftercooler" and oil cooler, as well as various enhanced vortech mechanics (8 rib belt and pulley system). This system not only keeps the oil in the supercharger and engine cool, but it also cools the air that comes from the blower, allowing for an increase in boost pressure. I was never happy that the original Dinan setup was so sensitive to ambient temperature. Heat soak and rising oil temperatures would rob me of practically all the power the supercharger provided in cooler weather. Since I drive my car a lot more in summer, a solution to this problem was important to me.

It wasn't a simple procedure to adapt the Dinan system to work seamlessly with the Dinan system, but thankfully I had some gifted mechanics on the job over at Carb Connection in Kirkland (www.carbconn.com). As you can see, the engine bay is now as full as it could possibly get! So full, in fact, that I had to sacrifice traction control to fit the aftercooler in. 400hp with no traction control - ouch! Anyhow, the car now feels like a 'properly' supercharged car. Accleration is fierce and never stops building until redline, but it's also perfectly linear.

The dyno sheet below shows a consistent gain in torque curve over the entire rpm band, making acceleration much more accessable.

Dyno sheet before and after RMS gear.

A bit about this dyno report. The original figure of 283 (~325 at the crank) is considerably lower than Dinan's quoted figure of 310 (~355 a the crank). I took this issue up with the installers (Seattle BMW) but they couldn't explain the difference. I later realised that it was ambient temperature reducing the power, thus making Dinan's horsepower claims optimistic and best. The RMS kit transformed the engine - 60 more hp and 40lb/ft more torque, with consistent power delivery, way less dependent on ambient temperature - the way it should be.