Focus ST Upgraded Turbo Recommendations

Focus ST Upgraded Turbo Recommendations

So, you are ready to increase the power a little more on your full bolt on (FBO) Focus ST?! Well, there are more than a few turbo options that you may be considering, and making a final decision can be hard! We have tuned hundreds (if not thousands) of big turbo ST's, so to make your decision a little easier, we have compiled some of the most popular big turbo options available for the Focus ST platform along with typical results that we see on each turbo.

Before upgrading your turbo, we recommend that you have the following bolt-on's: Intercooler, Downpipe, Accessport, Symposer Delete, Charge Pipes with a BOV flange, and Blow Off Valve. Fresh 1 step colder spark plugs (NGK) are always a recommendation (remember, proper maintenance will go a long way in helping your car meet your expectations). An upgraded intake and exhaust can help make the big turbo experience more fun in terms of sound, but they are not necessary. To get the most out of your big turbo set-up (especially for the super big turbo options, you may want to look into an auxilliary fuel system, such as the Stratified 2-Port or 4-Port options), otherwise the car may run out of fuel before the turbo really has a chance to meet its power potential.

Many people are interested in hybrid turbos, and while we have tuned hundreds of these set-up's, we do not sell them. You would need to contact the turbo manufacturers in most cases to purchase a hybrid turbo and find find out what their power estimates are. To keep this article simple, we will focus on just the big turbo options for now.

So let's get down to it! Many people ask which turbo we recommend for the Focus ST. This can be a hard question to answer if we do not know exactly what you will be using the turbo for and what your end power goals are. There are many factors that play into how much power you will end up with, including modifications, fuels used, auxiliary fuel systems, how healthy your car is, whether or not you have a built engine, and even how built your engine actually is. So I will start this list by highlighting our top 5 favorite big turbo upgrades for the Focus ST platform based on their characteristics instead of overall power. (Keep in mind that the dyno chart examples used in this article are all different types and levels of builds)

1. GTX2867R Gen 2 

The ATP Gen 2 turbos are really some of the best bang for the buck big turbos on the market for the Focus ST in our opinion! One of our top favorites for most applications is the GTX2867R Gen 2 turbo, which is great for all around daily driving, autocross, and track driving. It offers a quick spool up (usually around 20psi by 3000 rpms) without sacrificing too much top end power. You can expect to see around 360whp on stock fuel system and up to about 450whp with aux fuel and an e40 ethanol blend.

2. GTX2860R Gen 2

We love the GTX2860R Gen 2 because it is the fastest spooling upgraded turbo option that we have available. Again, the stock fuel system limits these cars to 360whp, but with an aux fuel system and an ethanol blend, you could expect to see around 400whp on this turbo. This turbo spools to 20psi by about 2800rpm (or less) in 4th gear, which makes it another great option for daily driving, autocross and track days. It is also great for a budget big turbo build as you aren't going to miss out on too much power by opting out of installing an aux fuel kit on your car.

3. Garrett G25-550 / Garrett G25-660

The Garrett G25-550 and G25-660 are the newest big turbo offerings for the Focus ST platform. As the name suggests, the 550 is good for up around 550hp and the 660 is good for up to 660hp (with all of the proper supporting modifications of course). We love these 2 options because they seem to be more efficient at making big power numbers. The 550 actually spools faster than the GTX2860 but has the potential to make more power that the GTX2867 Gen 2. The 660 spools as fast as a GTX2867 Gen 2, but can make more power than a GTX3071R Gen 2. One note that we have for these turbos that makes them different than the ATP kits is that they require a separate purchase and install of an external wastegate and dump tube.

4. GTX3071R Gen 2

This turbo is good for just over 500whp and hits 20psi in 4th gear at around 3800 rpms. We like this turbo because it has such a high power potential (this is actually the turbo that we are currently running on our time attack FoST). We have had great luck with this one and love the amount of power that we can obtain with this turbo, but we feel that it lacks some of the quick spool up that some of the newer options have to offer, which is a huge consideration for time attack track use (more time out of the power band = more time to get to the finish line).

5. EFR 7163

Unfortunately, we do not actually sell this turbo on our website so I can't give you a quick link for pricing information, but I could not leave this one out because it happens to be one of our favorite turbo upgrades of all time for the Focus ST. In fact, if we ever decide to go a different route on our time attack FoST, this would be at the top of our list as we think its characteristics would make a great time attack set-up!

With the proper supporting modifications, this turbo features 500+ WHP and very close to stock spool up times. The dyno chart below features a car with a Full Race EFR 7163 Turbo kit, Stratified 4 Port Aux fuel kit, a bit of head work with Stage 3 Esslinger cams, and a built bottom end with stock compression on an e50 blend. Once we finished dyno tuning, the car ended up at 522 Wheel horsepower and 435 FT Lbs of Tq.

NOTE: We were having issues with the dyno loading up properly, so the car was spooling much slower on the dyno than on the street. On the street this setup was making near peak boost by near 3200 rpms, but on the dyno it was making the same boost at around 4000-4500 rpms.

If this is the route that you choose to take for your big turbo upgrade, you can find them on mountune's website, and we would love to help you out with a custom tune and any other accessories that you may need to get started!


While the turbos above are our top 5 choices, there are many other great considerations:

GT2860RS - Good for up to around 350whp, 2900 rpms*

GTX2867R - Good for up to around 420whp, 3200 rpms*

GTX3071R - Good for up to around 490whp, 3800 rpms*

GTX2971R - Good for up to around 460whp,3500 rpms*

GTX2863R - Good for up to around 380whp, 3000 rpms*

GTX2871R - Good for up to around 440whp, 3400 rpms*

GTX3076R Gen 2 - Good for up to around 560whp, 4200 rpms*

*Spool up numbers are rough estimates based on a 4th gear pull to 20psi

Many of the turbo kits that we offer have an option to select which turbine housing you want (usually .64 A/R vs .86 A/R) While the differences vary by the turbo, the .86 A/R can generally make 10% more peak whp, but at the same time lose a few hundred rpm of spool up time vs the .64 A/R. We typically recommend going with the .64 A/R on all of the turbo options we have available if you plan on using the car for autocross/track use (if you haven't already noticed, we prefer to give up some peak power to have a longer power band). The .86 A/R's are usually great for those looking to make higher peak power numbers (the peak power numbers we have listed in this article use the .86 A/R turbine housing)


Previous article ST/RS Boost Leaks Discussed
Next article ST/RS Basic Modification Path and Power Estimates