Mini Cooper 3" x 4" Performance Cat Back Exhaust System


What's a 3" x 4" exhaust??  This simply means the exhaust diameter starts off at 3" then opens up to 4".

Why change the diameter of your exhaust?  Easy - less Back Pressure. Think about it - if you have a 4" opening in and out of the muffler, it will flow better with less back pressure compared to a muffler with 3" in and out.

So What Does a 3" x 4" Cat Back Exhaust System Do?


Here is a detailed discussion on the design of the Mini Cooper 3" x 4" Performance Cat Back Exhaust System for the 2007+ R56 Mini Cooper S Hardtop and the R58 Mini Cooper S Roadster:

It's a law of physics that hot air is lighter and flows better than heavier dense cool air.

If this law is used properly, this same principal can be applied to your cars exhaust to give you more power. Your restrictive factory thin walled non-insulated exhaust is not designed to hold in heat. As the air cools that heat is released into your engine and drive train and the flow slows down because the air is now more dense.

This means that your engine has to push the exhaust out because the cooled air is heavier. Not to mention now the thick air must pass through a restrictive baffle filled muffler which reduces the volume that can flow out your exhaust even more. All of this costs you and you pay that bill with less horse power and reduced efficiency and unfortunately that is not the worst of it.

Since the air flow is moving slower it backs up behind the catalytic converter that is located in the worst place possible which is under your hood a few inches away from your turbo. All of that backed up hot air in the exhaust causes heat to soak into your engine, turbo, and undercarriage damaging them. And the bigger the turbocharger and more upgrades you have the more heat is built up and the quicker your turbocharger and other parts will fail.

Our Fully Heat Wrapped 3x4” Exhaust System


All exhaust systems on the market today focus on one aspect of the many problems that cause power loss and none on the damage that heat can do to your engine and turbo. When we did our design we took in to account all the factors that can cause power loss and damage. That is why we developed our fully heat wrapped 3x4” exhaust system which takes full advantages of the simple laws of physics and heat transfer.

We didn't just solve one of the problems with the average exhaust system, we provided a solution for them all.

Eliminating the Issues Once and For All


Back pressure also prevents your turbo from spooling quickly because the air speed is slowed or blocked. This is why baffled mufflers are not recommended for turbocharged cars. Also the longer the hot exhaust is in the exhaust system the more the heat can soak through it, and unfortunately most of this heat is released into your turbocharger, engine, and undercarriage.

To eliminate all of these issues we open up the exhaust to a massive 3" then 4” using only mandrel bends, which gives you double the volume of air flow. But we don't stop there, we delete the restrictive muffler or give you an option for a baffle free full flowing straight through race inspired muffler. Just these two options would be enough to let your realize outstanding performance.

Getting The Most Power For Your Money


But we want to make sure you get the most power for your money, help out your turbo to produce more power and torque, last longer, and use all of the laws of physics to your advantage, so we take it a few steps farther. That is why we complete it with the final step and fully wrap it to prevent heat loss. This keeps the air hot and light preventing power loss due to the cool air reducing velocity and keeps the heat where it should be and out of your engine and turbo.

Using all of these simple techniques our exhaust system will benefit you in too many ways to list.

Since we open up the exhaust to 3" then 4”, it can flow a huge amount of volume of air. Then we wrap it so the exhaust doesn't slow and flows quickly out the exhaust before the heat soaks into your engine and turbo. Then we delete or relocate all of the restrictions so there is less back pressure. 

Now a larger volume of air can flow through it:
  • It flows faster
  • It takes less power to move it out
  • And most importantly it keeps the heat in your exhaust where it belongs