The Top 5 Ford Focus ST Speed Upgrades. The Ford Focus ST was manufactured from 2012 to 2018 and came standard with a 2.0L I4 EcoBoost engine. The 2.0L EcoBoost engine is one of the smaller engines in the EcoBoost family, and it doesn’t always get the credit it merits because the 2.3L, 2.7L, and 3.5L versions outsize and outpower the Focus ST’s engine.
The Focus ST’s 2.0 turbo engine generates 252hp and 270lb-ft of torque out of the box. Fortunately, the turbocharged design enables substantial power gains with only a few bolt-on modifications. With the performance improvements discussed in this guide, the Focus ST is capable of 300+whp.
First Generation vs. Second Generation 2.0 EcoBoost
The Ford Focus was discontinued in 2020, but the Focus ST was terminated in 2018. The Focus MK3 (C436) models were the only generation of Focus ST manufactured. However, Ford introduced numerous updates to the 2.0L EcoBoost engine in 2016.
Before we get into the best Focus ST mods, it’s important to grasp the differences between the models from 2012 to 2015 and those from 2016 to 2018. The improvements eventually made the 2016+ Focus ST models more capable in terms of tuning and performance.
The following are the changes to the 2016+ 2.0L EcoBoost engines:
- Compressor conversion to twin-scroll
- New and improved metal block
- The compression ratio has risen from 9.3:1 to 10:1.
- A completely new engine head
- Upgrades to the gasoline and oil systems
The engine was updated to enhance low-end torque as well as overall engine and turbo efficiency. While the updates did not raise stock power levels, they do make the 2nd generation engines capable of producing more power.
That being said, a Focus ST with a second-generation 2.0 EcoBoost and the same exact mods will likely generate around 15whp more than a 2012-2015 ST. While not particularly significant, it is something to consider if you are contemplating purchasing a Focus ST for performance purposes.
The Top 5 Ford Focus ST Engine Modifications
The following are the finest Ford Focus ST upgrades:
- SWF Optimizer
- Efficiency Consumption
- Downpipes
- Intercooler (FMIC) (FMIC)
- E85 Fueling
In our view, these five mods are the best starting point for a Focus ST. One item we purposefully left off the list was turbocharger upgrades. Turbo upgrades necessitate a lot of thought and additional supporting mods, so we’ll cover them in their own article later on.
These modifications are not listed in any particular order, but we believe that a tune and intake are the two best locations to start. This guide will go over the aforementioned mods in greater depth, including the performance benefits, power gains, and costs.
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1. Flash Tuner Focus ST
A flash tuner is one of the best Focus ST modifications because it provides the most bang for your money. Furthermore, a tune serves as the basis for further customization. When paired with the other mods on this list a tune can add up to 50whp and 70wtq.
We consider tunes to be the foundation of mods because without them, the other mods on this list will not provide the greatest benefit. Tunes change the fueling, AFRs, boost targets, and other parameters based on the car’s other modifications to optimize the power gains from the additional upgrades.
While custom or dyno tuning are options, we suggest beginning with a flash tune. If you choose custom tuning, you will need to have your vehicle re-tuned every time you modify it. Flash tunes, on the other hand, automatically adjust when other upgrades are introduced and come with a variety of various prebuilt tunes. Unless you are having it dyno tuned, custom tuning still necessitates the use of a flash converter.
Top Focus ST Sounds
Because flash tuners have pre-programmed tunes, choosing a tuner from a reputable business is critical. While the Focus ST has a limited selection of tunes, there are some extremely reputable options:
- Accessport Cobb
- SCT X4
The two most common Focus ST tuners are Cobb and SCT. When selecting a tuner, you have a few other choices. Companies like Stratified Tuning offer the Cobb Accessport along with custom remote tuning services. Other companies provide the same service for the SCT, but almost every reputable custom tuning company employs either Cobb or SCT for the Focus ST.
To begin, we suggest purchasing the flash tuner and then considering a custom tune once you have completed all of the mods you intend to install. Both of the above options are fully plug-and-play and include a variety of pre-programmed tunes.
Power Increases from the Focus ST Tune: 20-50whp and 30-70wtq
2. Focus ST Intake Improvement
After a tune, an upgraded intake is arguably second on our list of best first mods. Tunes mainly increase power by increasing the amount of boost produced by the turbo. Increasing boost necessitates increased ventilation. The stock intake is fairly decent out of the box and should be fine for a Focus ST with a mild tune. However, as you run a more aggressive tune and further alter your engine, the stock intake becomes restrictive.
Because the stock system is quite good, you should only anticipate 5whp from an intake on a stock ST with a mild tune. However, with the extra mods on this list and a more aggressive tune, those gains can reach around 10whp.
Another advantage of tuning is that it increases the efficiency of the turbo, making it more dependable. The more air that enters the engine, the less work the turbo has to do to pressurize it, reducing stress and boosting horsepower and reliability.
Cool Air Intake for the Focus ST Ben
- 3-10whp and torque increases are comparable.
- Increases in ventilation of 40% or more
- Increased turbo efficiency and faster turbine spool
- The intake and turbo noises are excellent.
Intakes: Open Air vs. Closed Enclosure
The phrase “cold air intake” isn’t always applicable to an upgraded Focus ST intake. Cold air intakes reroute the air filter to the engine’s bottom portion, sucking in more outside air and less engine bay air. Because all Focus ST intake systems use the factory intake location and do not reroute the filter, they are not true cold air intakes.
There are two types of intakes: open and confined. The air filter in an open intake system is fully exposed to the engine bay air. Closed systems will place the air filtration inside an enclosed box to prevent hot engine room air from entering the intake.
Open intakes will result in greater airflow increases and, as a result, marginally higher power gains. Closed intakes provide less airflow, less power increases, and slightly cooler intake air temperatures. However, because the intake air is already heated by the turbo and then passes through the intercooled, the advantage of colder intake air temperatures is almost non-existent.
As a result, we favor open air systems because they increase air flow the most and are the least restrictive.
Focus ST Intakes at Their Finest
The following are some of the finest Ford Focus ST 2.0 EcoBoost intake upgrades:
- AF Dynamic – true open air system with the greatest price-to-performance ratio
- K&N is one of the most reputable brands on the market, with a reasonable price for reliable product.
- Roush – while this looks to be an open system it actually seals with the hood making it enclosed. It does not invalidate the warranty.
3. Focus ST Downpipe Modification
Downpipes are specific to turbocharged motors and are the first component of the exhaust system in turbocharged vehicles. The downpipe is immediately connected to the turbo and houses the primary catalytic converter. Because the downpipe is catted, it is extremely limiting. This limitation causes a lot of backpressure for the turbo, lowering its efficiency.
The standard downpipe is excellent for emissions but deplorable for performance. You want as little backpressure behind the turbo as possible, which is why upgrading your downpipe is an excellent performance mod. Aside from increasing power, it also enhances turbo reliability.
Check out our Focus ST Downpipe Tutorial for a more in-depth breakdown.
Advantages of an Improved Downpipe
The following are some of the advantages of Focus ST downpipe upgrades:
- Gains of 5 to 15 watts
- Gains of 10 to 20wtq
- Quicker turbo boost
- Increased turbo performance and dependability
- Exhaust sound is slightly louder (not as obnoxious as a cat-back)
Lower backpressure results in lower exhaust gas temperatures and less stress on the turbocharger, enabling it to spool more quickly. You might read on forums or other websites that you should upgrade your cat-back exhaust system and that the downpipe doesn’t matter as much. This is entirely untrue. The downpipe generates almost all of the exhaust backpressure, which is why it provides such significant power increases.
Expect to see similar power increases with a cat-back or even a full exhaust system unless you also upgrade the downpipe.
Catless vs. Catted Downpipes on the Focus ST
A catless downpipe is simply an exhaust pipe that has no restriction inside of it. As a result, it provides the greatest power gains because it eliminates virtually all of the backpressure generated. The disadvantage is that it removes the catalytic converter, making it illegal.
The legal option is going with a high-flow catted downpipe. By using a less restrictive internal structure inside the piping, these downpipes keep the exhaust legal and emissions friendly while still improving exhaust flow and reducing backpressure. They still provide great performance benefits and improved exhaust flow, but a high-flow downpipe on the Focus ST will produce about 5whp less than a catless downpipe.
Another disadvantage of high-flow options is that they are more expensive. Catalytic converters contain rare earth metals, which makes them much more expensive than a catless downpipe, which is essentially a hollow piece of stainless steel.
CVFab is the best Focus ST downpipe.
Our favorite Focus ST downpipe on the market is available from CV Fabrication. Its price of just over $400 makes it one of the best bang-for-buck high-flow downpipes on the market. The CVFab downpipe is made of stainless steel and measures 3 inches in length. It has the same fitment and quality as the more expensive brands on the market.
CV is one of our favorite EcoBoost engine manufacturers. Their products are of high quality but are reasonably priced in comparison to other brands on the market. They are suitable for almost any EcoBoost engine.
Due to EPA crackdowns, no one sells catless downpipes online anymore. In our opinion, the best option is a CVFab catted high-flow downpipe. Cobb offers a full turbo-back exhaust system with a catted downpipe and cat-back system for $1,425 if you also want to upgrade your full exhaust system. We really only recommend getting a full system if you want a louder exhaust note because you won’t get much more performance for the extra $730 that turbo-back systems cost.
Upgrades to the Intercooler (FMIC)
Front mount intercoolers are critical not only for performance but also for reliability. Intercoolers do not provide the most power gains, but they do provide more consistent power delivery and lower engine temperatures.
The stock intercooler works well on the stock engine, but when you add a tune and boost, it quickly becomes overwhelmed. The stock intercooler begins to heat soak and is unable to efficiently cool large amounts of air before entering the engine. As a result, a large amount of hot air is forced into the combustion chamber.
Because hot air is less dense, the engine pulls timing to prevent misfires and pre-detonation issues. Heat soak can cause you to lose power quickly if you consistently hit the throttle, whether driving aggressively on the streets or during track days. When the stock intercooler experiences a lot of heat soak, you can lose around 20whp.
An upgraded intercooler will add about 5-10whp while also preventing the engine from losing power while driving aggressively.
Advantages of an Upgraded Intercooler for the Focus ST
The following are some of the advantages of Focus ST FMIC upgrades:
- Gains of 5-10whp and similar torque gains
- Reduce intake air temperatures
- Heat soak reduction ensures consistent performance.
- Reduced likelihood of misfires or pre-detonation
CVF Street Intercooler is the best Focus ST intercooler upgrade.
CVFab, like downpipes, offers our favorite intercooler on the market. At $500, it offers one of the best value-for-money combinations of quality, performance, and price. For maximum cooling capacity, the street intercooler is 115% larger than the stock intercooler. In street testing, the intake air temperatures are reduced by 41 degrees compared to the stock intercooler. Furthermore, the massive intercooler core allows for up to 670whp, which can support almost any aggressive Focus ST build.
Furthermore, if you want more airflow, we recommend combining the CVF street intercooler with an intercooler piping kit. The piping kit includes both the cold side chargepipe and the hot side piping, both of which are very restrictive out of the box. Airflow from the turbo to the intercooler and from the intercooler to the engine will be improved as a result. You can also choose a chargepipe with a HKS flange to accommodate a HKS SSQV blow-off valve for cool sounds.
5. Fueling for the Focus ST E85
First and foremost, if you are tuned, make sure you are using 91 or 93 octane fuel. Higher octane fuel allows for more precise timing and reduces the likelihood of engine knock. While race gas is an option, it is extremely expensive and not always readily available. As a result, E85 ethanol fuel is the best choice for the Focus ST.
The 2.0 EcoBoost’s stock fueling system can handle an E85 blend. While running 100% E85 will necessitate some fueling upgrades, an E30 blend can be safely run with the proper tune.
Ethanol, also known as E85, has an octane rating of 108. Furthermore, it burns cooler and cleaner than traditional gasoline, allowing for more aggressive timing and boost. An E30 blend combined with a proper ethanol tune can add 10-15whp to the Focus ST.
Power gains are even greater when running 100% E85, especially when combined with an upgraded turbo, but this will necessitate fuel pump upgrades, port injection, and other modifications.
Advantages of E85 Fuel
- 10-15whp and torque increases
- This enables more aggressive timing.
- Allows for a greater boost
- E85 is less expensive than regular gasoline.
Methanol injection is an additional option for running E85. This, however, requires a standalone methanol injection kit and is a more advanced fueling mod that we will not cover in detail in this guide.
6. Ford Focus Engine Mounts
This is an optional Focus ST upgrade that we recommend to all owners who want to increase the power of their 2.0L Focus engines. The engine in the Focus ST shakes a lot. This causes significant wheel hop and bounciness between gears.
The stock motor mounts are way too soft which allows the engine to shake too much. When you add mods and more power to the ST, the engine shakes even more, resulting in even more wheel hop. This results in less power being sent to the ground, making your car feel slower than it should under hard acceleration. It also makes the car harder to control while accelerating.
Stiffer motor mounts cost around $150 and will provide significantly more traction and grip on the road when you want to floor it.
Power Potential of the Ford Focus ST
We consider the 5 mods listed here to be “full bolt-on”. While there are other modifications you can make, such as a full exhaust system or an intake manifold spacer, we left these off the list because they don’t provide enough power gains to justify the costs. Your Focus ST will produce 300-320whp and 340-360wtq with only these modifications. Given that all of these modifications can be completed for under $2,000, the Ford Focus ST is a very mod-friendly vehicle.
While the 2.0 EcoBoost is capable of handling more power, reaching those levels will necessitate an upgraded turbo, advanced fueling modifications, and eventually internal upgrades.
To summarize, when it comes to modifying your Focus ST, a tune is the best place to start. A tune is the most effective upgrade for power gains, providing up to 50whp gains. Following that, an upgraded intake is suggested to help the engine and turbo get enough air for the increased boost. Unless you want a louder exhaust note, the only exhaust modification we recommend is an upgraded downpipe. The power gains from a cat-back exhaust system are insufficient to justify the expense. Following that, an intercooler is suggested to provide more consistent power, prevent power loss, and improve engine reliability. Finally, the best “free” mod is using E85 fuel in conjunction with a proper ethanol tune. CVFab is our preferred manufacturer for ST intercoolers and downpipes.
Ford understated the power numbers of the Focus ST from the start, with bone stock cars dynoing in the 240-250whp range. These five best mods will get you to 300-320whp, which means you can gain up to 80whp for less than $2,000 in mods. Keep in mind the differences between the first and second generation EcoBoost engines. First-generation engines will most likely fall on the lower end of all quoted figures.
