Mini Cooper 2001-2006: Exhaust Reviews and How-to

This article applies to the Mini Cooper (2001-2006).

Installing an aftermarket exhaust is one of the most popular modifications enthusiasts make on modern vehicles, and for good reason. It's one of the easiest ways to free up some extra horsepower and give your car a much better sound. Whether you plan on making a little or a lot of modifications to your car's engine, the right exhaust setup can make a big difference in more ways than one. Plus, they aren't too difficult to install. Keep reading and we'll walk you through the installation process, plus review some of the most popular exhaust systems available for the Mini Cooper today.

How to Replace Your Exhaust

Step 1 – Prepare the car for exhaust removal

Before beginning, allow the car to cool off completely if it has been in operation. This not only reduces the chance that you might get burned by a hot exhaust, but it also makes the bolts on the catalytic converter easier to remove. Jack the rear of the car up and place it on jack stands, or back the car up on a pair of ramps (be sure to chock the front wheels if you do this for safety). Remove the four 10mm plastic nuts that hold the battery tray in place and pull it out.

Step 2 – Remove stock exhaust system

Unbolt the center pipe from the catalytic converter by removing the 15mm nuts and bolts. Set a cardboard box underneath the cat to support it, then remove the center body hanger, which is held in place by 10mm bolts. Move to the rear of the car and remove the 10mm bolts that hold the mufflers to the rubber hanger brackets, holding the mufflers as you do this to keep them from falling. Lower the exhaust system and slide it out.

Step 3 – Prepare new exhaust system

Depending on which exhaust system you have purchased, installation may vary just a bit. Be sure and read the installation instructions that come with your exhaust to note any differences, i.e. if they come with the nubs for rubber hangers. Remove the factory muffler brackets by removing the two 13mm nuts holding the outside hanger in place, then prying the inner piece of the bracket off with channel locks. Spray them down with some penetrating oil if they prove to be stubborn to remove. Remove the center hanger from the old exhaust by removing the six 10mm bolts and rubber hangers, then install it on the new exhaust. Remove the rubber hanger from the factory muffler bracket and reinstall them in the car.

Step 4 – Install new exhaust system

Slide the new exhaust under the car and into the clamps, but don't tighten them just yet. Set the new muffler in the rubber hangers and use the channel locks to push the nubs into the hangers. Lift the center pipe up until it reaches the catalytic converter, reinstall the gasket, and reinstall the bolts. Tighten them using a wrench and a socket. Line up the center body hanger with the bolt holes and reinstall the bolts. Line up the exhaust tip where you want it and then tighten up all the bolts. Start the car and listen for leaks, then adjust if necessary.

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Exhaust Systems Review

Replacing your stock exhaust with a free flowing aftermarket unit can not only free up some horsepower, but it can also give your Mini a nice, throaty exhaust note. There are a ton of options available, so it can be tough to figure out which one is best for your particular needs. What follows is a review of four of the most popular options available that will help you pick out your next exhaust system.

Milltek Sport

Price – $899-$945

Power Gain – 9 HP and 7-9 lb-ft of torque

Pipe Diameter – 2.5"

Weight – 31 lbs

Milltek makes a quality cat-back exhaust system for the Mini Cooper that is 100% stainless steel, so it won't corrode like the stock exhaust. It also provides a bigger power boost than many others out there. Milltek's exhaust is almost as quiet as the stock exhaust as well, so you won't wake the neighbors when you fire it up for a late night cruise. Recommended for anyone looking for an upgrade over OEM and doesn't want a loud, obnoxious exhaust.

Alta Polished/Stealth

Price – $675-$850

Power Gains – 8 HP and 5-7 lb-ft torque

Pipe Diameter – 2.5"

Weight – 22 lbs

Alta exhausts are also stainless steel, but weight considerably less than the Milltek system. While older units had issues with discoloration on the tips, the problem was fixed with some pre treating on the newer ones. Fitment was also an issue that has been fixed from early units. Oval tips and dual tips are available for you to choose as well. Recommended if weight is an issue, and the polished exhaust is pretty affordable as well.

Magnaflow

Price – $550-$600

Power Gain – 8-10 HP

Pipe Diameter – 2.5"

Weight – 34 lbs

A reputable name in the exhaust business for a long time, Magnaflow offers a pretty affordable, quality option for Mini Cooper owners. It's a bit heavy and noisy, however, so those could be concerns for those obsessive about those things. Recommended for those who want a quality exhaust on the cheap and don't mind the noise.

Borla Street/Sport

Price – $650-$700

Power Gain – 5 HP and 8-9 lb-ft torque

Pipe Diameter – 2.25"

Weight – 34 lbs

The Borla Mini exhaust is very similar to the Magnaflow, both coming in at the same (heavy) weight and both producing an equally loud exhaust note. Borla, like Magnaflow, has also been in the exhaust game for a long time, and both represent a great value. Recommended if you don't mind the weight and noise for a cheap, quality exhaust system.

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