What is a turbocharger 'upgrade' for the MINI Cooper S?  

Upgrading your MINI Cooper Turbo Charger can be the most satisfying horsepower you can have. But knowing the differences in MINI Cooper Turbochargers is the key. Quick guide helps explain the differences in MINI Cooper Turbochargers technologies ranging from :

  • JMTC Hybrid Turbochargers
  • K03 Quick Spool
  • K04 High Flow
  • JMTC Billet Compressor Turbine Wheels
  • JMTC Turbochargers and Manifold Porting

turbo JMTC Hybrid Turbochargers

JMTC Hybrid Turbochargers are a combination of the different turbos to get the desired performance of overcoming restrictions or limitations of the OEM design and are upgrades for strength.

They work best on cars that have stock components. For example if you want to increase the high boost levels then the OEM turbo can produce, normally you would install a larger turbocharger. This will work fine in the days before catalytic converts and restrictive intake systems designed to restrict flow and pass EPA environmental standards. However, now due to the restrictive OEM components your new turbo spools up 1000 to 2000rpms later and you loose bottom-end torque and power.

Your new upgraded turbocharger has now become a downgrade rather than an upgrade. This is because it doesn’t provide full boost until 4000 or 5000rpm. Meaning you lost the race because your competitor with less power had quick of the line power and got a 3 to 5 car jump on you. Quick off the line response and in drag and street race this can mean all the difference especially on a short 1/8 mile track or low speed short race.

The hybrid turbo will retain most bottom-end torque and still retain most of the top-end power, and we do this by using a mix of components. Increasing the compressor size will add a larger volume of air at low RPMs just like the OEM turbocharger. Also by retaining the smaller exhaust turbine it will speed up the air so it can make it through the restrictive head, exhaust manifold, and catalytic converter quickly. This way you use the restrictive exhaust turbine to your advantage. It will make the air flow faster to help speed of the air on the hot side pushing it out quickly. Hybrid are not without there disadvantages due to the small size exhaust turbines they are susceptible to boost creep and excessive heat if the engine and exhaust system flow extremely well and sometimes will limit the power or torque at the top-end. If this happens it is a good indicator that it is time to upgrade to a larger exhaust turbine like on our S42R or E/B45R K04 turbochargers.

Our JMTC Hybrid Turbochargers Fit all GEN2 Cooper S and JCW Models  with N14 and N18 engines (R55 R56 R57 R58 R59 R60 R61 - 2007-2016)

K03 Quick Spool

When we say K03 we are referring to the exhaust turbine size. The K03 is the size of the turbocharger exhaust turbine chosen by Mini Cooper and is used on both the OEM MCS and JCW as well as our JM40 (or our version of the JCW), S42HP, and E45HP.

Both of our S42HP and E45HP are hybrid turbochargers because they use a combination of parts from the OEM and part form larger K04 turbos. We call them “Quick Spool” because they both spool very fast because they retained the smaller K03 or OEM turbocharger exhaust turbine. Using the mix of different turbochargers parts has given our JMTC hybrid and K03 turbochargers added durability as well as quick spooling speed. They were designed for and work best regardless if they are used with some of the restrictive OEM components. See Hybrid turbocharger section for more information on their recommended usage.

K03 Turbochargers listed below fit all Gen2 MINI Coopers R55 R56 R57 R58 R59 R60 R61 models (2007-2016)



K04 High Flow (K04 is high flow for Mini Coopers)

When we say High flow we mean it, the K04 turbocharge has larger exhaust turbine which is designed to increase the amount of air flowing though your engine. Since the exhaust turbine is larger it will spool up a little slower but wait until the top end. This means that instead of spooling up at 1800rpms like in the OEM K03 turbocharger the K04 will spool up at 2800rpms to 3000rpms.

There are ways get the turbo to spool sooner and the best are changing to a larger exhaust (like 3” or 4”) with a bigger high flow catalytic converter, using a high flow intake, head and exhaust manifold poring. We only recommend using a K04 on a mini cooper that has had a lot of upgrades designed to increase air flow, for example full 3” or bigger exhaust, aftermarket intake, and porting.

K04 Turbochargers listed below fit all Gen2 MINI Coopers R55 R56 R57 R58 R59 R60 R61 models (2007-2016)




Premium JMTC Billet Compressor Turbine Wheels

Billet compressor wheels are machined from a solid block of billet aluminum. Most compressor wheels are made from cast material, meaning the metal is heated to the melting point and pored into a mold. This can lead to imperfections in the materiel such as casting voids or week spots where the materiel didn't bond. Sometimes there might be slight differences from one side of the molded component to the other. Most of the casting differences do not effect the operation of the turbine but they can effect the efficiency in a minute way. The cast process does work well enough for a turbocharger that is used for normal street applications. However if you are running boost levels above 18 to 19psi they can flex, bend and in some cases come apart altogether.

Our JMTC Billet compressor wheels do not suffer with any of these problems and there are several reasons for this, most are all centered around the strength of the material used. Since we use a blank of high strength forged aluminum, we are starting with material that doesn't have any imperfections or flaws. This means that our JMTC Billet turbine wheel will still be stronger than a cast turbine wheel. In fact the material added to hold a cast wheel together doesn’t need to be as big on a JMTC Billet turbine wheel and the JMTC Billet wheel will still be stronger than a cast turbine wheel.

This means that a JMTC Billet wheel can be made lighter and will still be much stronger than the cast wheel. But this is not the only advantage, a large portion of the compressor turbine (meaning the part that makes pressure or boost) is used in a cast wheel to make it stronger. Since we reduce the large area used to make a cast wheel stronger, the JMTC Billet compressor turbine will actually have more area to make pressure or boost. This means the compressor portion of the turbine is larger and lighter, which makes our JMTC Billet turbochargers spool quicker, and perform better than a turbocharger with cast version of the same turbine.

But the benefits don't stop there, since cast materiel is susceptible to warpage, there are casting asymmetry and it is weaker and more flexible than our JMTC Billet compressor turbine wheel. All of these characteristics make it more inefficient, weak, and it wont be able to perform as well at high boost levels as well. Even worse when it is run in extreme environments like racing or high boost pressures it can fail due to over spinning. Since our billet wheels are machined on a 5 axis mill there are no asymmetry issues, it doesn't warp, and the high strength material will resist flex at high boost levels.

Using our JMTC Billet compressor turbine wheel will help turbocharge to spool faster, provide more flow, run more efficient, and reduces the chance of wheel burst. There are no disadvantages to using a our JMTC Billet compressor turbine wheel and we recommend as they are the number one turbo performance improving upgrade to improve you turbocharger. That is why we recommend them for all extreme street, race and strip application.

JMTC Turbochargers and Manifold Porting

The rough cast surface inside the turbocharger compressor, exhaust housing, and exhaust manifold increases friction and slow the air. This reduction of the volume of air that can pass through them equates to less power, torque, and more built up heat in the incoming air (in the turbo and head). The only way to combat this is to port the turbocharger, head, and or exhaust manifold. This will allow the air to flow much faster because there is less friction. If you want to increase power, top-end power, and torque, reduce heat caused by air friction, take advantage the increased flow and volume than porting is the way to go.

Don’t leave power on the table, the Mini Cooper heads don't flow that well - only abut 125cfm. So if you want to get the most out of your Mini, you need to do everything to reduce the engine restrictions. Turbocharge, manifold, and head porting are a must to help you squeeze all the power you can out of your Mini Cooper. That is why we offer our porting service, when we port and port-match (match the exhaust inlet and outlet sizes to the sizes of exhaust manifold and down-pipe) service.

What Does Porting Do?

Porting Service lowers both incoming and outgoing air temps, increases air volume, speeds up the air, and increases efficiency so your turbocharger can hold a stable target boost pressure and max flow to red-line.  To learn more, please read our article  What is Turbocharger Porting .)