Best BMW M4 Mods in 2024

Some of the links on this page may link to our affiliates. Learn more about our affiliate policies.

Last Updated: December 22, 2023

F8X BMW M3 and M4 Carbon Fiber Lip Spoilers

Every BMW M car from the factory is missing the front lip spoiler. Once you add the front lip to the car, something needs to be added. Therefore, that's always the first mod that I do. The current F82 M4 received a carbon fiber lip from RW Carbon (BMW F8X M3/M4 CS Style CF Front Lip Spoiler w/ SLiPLO), which was costly, but the quality made it worth it.

So that's the looks part of the vehicle, but does the front lip have anything of value to offer you performance-wise? The short answer is yes. Front lip spoilers play a part in creating the downforce for your vehicle to make your car more planted to the pavement.

What's the price point for this mod? The price ranges quite a lot; it all boils down to the quality. Front lip spoilers for M4s and M3s cost $85 on eBay, but the quality probably reflects the price. They will not be made out of real carbon fiber and will most likely have no carbon fiber.

Price range: $85 - $5950

F8X M3/M4 Rear Diffuser Upgrades

While the rear of the BMW M4 is pretty complete, adding a carbon fiber diffuser will make it pop even more. The F80 M3 already has a super wide-looking rear, but with a diffuser upgraded, it looks even meaner. This time, I went with the RW Carbon diffuser with the brake light in the middle. I know that I might be too old for such a racecar look, but I don't think we will ever get too old to drive racecars.

In automotive engineering, a diffuser is a meticulously designed component integrated into the rear section of a vehicle. Its primary function is to optimize aerodynamic performance. This is achieved by facilitating a more efficient transition between the high-velocity airflow beneath the vehicle and the relatively slower ambient atmospheric airflow. The diffuser's strategic shaping and positioning are critical in reducing drag and improving downforce, enhancing the vehicle's overall aerodynamic efficiency.

There are a few different types of diffusers

• OEM size diffuser: this type of diffuser directly replaces the OEM diffuser for a more aggressive look. It only covers the middle bottom portion of the rear bumper.
• Three piece diffuser: OEM size diffuser plus two additional pieces on each side for a full rear bumper coverage.
• Four piece diffuser: three piece diffuser plus undertray. Undertray is usually not seen unless the car is lifted.
• One full piece (like the one in the picture above), covers the whole bottom of the rear bumper. It usually clips onto the OEM hooks in the middle part, and have to be screwed into the sides.

Price range: $110 - $2500

BMW F8X Side Skirts

If you put on the front lip and a diffuser on your BMW M4 or M3, the look will not be complete without a matching pair of carbon fiber side skirts. I always thought I didn't complete my Austin Yellow M4 because I never ended up putting on side skirts. However, I made no such mistake with the 2018 BMW M4 ZCP again. It has received the full carbon fiber aerodynamic pieces menu, served by RW Carbon.

To achieve optimal aerodynamic performance, it is essential to maintain a smooth, uninterrupted airflow from the front to the back of the vehicle. Utilizing side skirts is a strategic approach to this objective. These components act as barriers, preventing air from flowing chaotically underneath the vehicle and adversely affecting aerodynamic efficiency. The effectiveness of side skirts is directly proportional to their proximity to the ground; the closer they are, the more they enhance the vehicle's aerodynamic stability by minimizing disruptive undercarriage air currents. If you aren't planning to lower your vehicle, putting side skirts on will also create a slightly lowered look.

BMW M3 & M4 Trunk Spoilers

Trunk spoilers look amazing when done right, but there is a thin line between making your car look classy and tacky. Some folks choose to go all out and put a huge "wang" that might throw off the car's profile, so don't be like them. However, even large spoilers can make your BMW M4 or M3 look great if you choose it with taste.

A trunk spoiler on a car helps alter the vehicle's airflow dynamics. This alteration aims to decrease wind resistance and augment downforce, thereby significantly enhancing traction during high-speed maneuvers. Integrating a trunk spoiler can be a crucial aspect of the build specifically tailored to improve a sports car's stability and performance by optimizing its interaction with air currents. This mod might be a must for someone who spends time on a track.

BMW M3 & M4 Cannards

I was never a fan of the canards, but I've seen some SEMA-type builds that look extremely aggressive with them on. Depending on how aggressive and mean you want your F8X BMW to look, you should either sit this one out or go all in. From a look's perspective, opinions about canards are mixed. However, they do have added benefits to aerodynamics.

The strategic placement of canards facilitates the formation of vortices, which play a crucial role in maintaining airflow attachment to the vehicle's structure. These vortices draw air out of the fender wells, thereby reducing pressure and directing the airflow behind the tires. Consequently, airflow moves along the car's sides, significantly reducing lift or enhancing downforce. This aerodynamic intervention is vital in optimizing vehicle performance, particularly regarding stability and efficiency.

Front Splitters or Fangs

If you live in an area where entrances and exits from parking lots are steep, ditch the front lip spoiler and go for a set of front splitters, otherwise called fangs. I have had them on my Austin Yellow BMW M4 when I was still quite scared of putting a front lip on due to decreased ground clearance. 

The purpose of this add-on is purely aesthetic. If you have a black BMW F8X, it might not make sense to put black fangs since people would have difficulty telling if it's even there. If you have a lighter-colored car, it will add to the already astonishing look of your vehicle.

Wheels

This a deep topic of its own. Some people love stock wheels so much that they will never think about changing out their BMW M4 wheels. However, some folks could be building a show car or need lighter wheels for racing, and others simply might look for a different look. Either scenario works well for different people. 

I tried different looks on the AY M4, but due to financial constraints, I only explored my options after the Velgen wheels that I briefly put on the car. I love the style 666M Shadow Black BMW M4 wheels, so I am not planning on making changes soon. 

Things to understand

Similar to the carbon fiber parts topic, wheels are built very differently. They can be cast, forged, or even carbon fiber:

• Cast wheels are made by melting a metal to the point of liquid, pouring it into a mold, and leaving it there to solidify. These wheels are the most popular and easy to produce on the market. The downfall is that they are heavier than the other two types of wheels.
• Forged wheels: These wheels are made out of a block of metal that's heated and shaped using very high pressure. They are stronger and lighter than cast but will cost much more.
• Carbon fiber wheels: Carbon fiber wheel manufacturing involves layering carbon fiber cloth in a mold, infusing it with resin, and then curing it to form lightweight, strong wheels. This process produces significantly lighter wheels than traditional metal ones, enhancing vehicle performance through reduced weight and improved handling.

Carbon Fiber, BMW M3/M4 CS or GTS Style Hood

Purchasing a carbon fiber hood for a BMW M3 or M4, including high-performance variants like the M3/M4 CS and M4 GTS, offers several benefits. Firstly, it reduces the vehicle's weight, enhancing handling and acceleration. Secondly, it often features integrated vents for improved engine cooling, crucial for maintaining performance. Additionally, the distinctive look of carbon fiber adds a stylish, aggressive aesthetic, aligning with the exclusive design of models like the M3/M4 CS and M4 GTS. This upgrade can also potentially increase the car's resale value, appealing to enthusiasts who value performance and style.

Price range: $1200 - $9800 (as always the price will mostly depend on the quality, materials, and branding)

BMW M3/M4 Air Intake System Upgrades

In the image above you can see a set of red air filters showing through the grill of my former BMW M4. These intakes were produced by RK Autowerks, back in the day when the company was just starting out. Sadly, RK doesn't manufacture air intakes for F8X platform anymore and is now focused on much more involved parts manufacturing like making their own turbo kits or forged engines.

There are two common types of air intakes that F8X M3 and M4 owners can purchased:

• Front mount air intakes
• Engine bay air intakes

Both of these choices will add an additional sound effect to your already loud BMW. I used to love driving down a street between buildings and downshifting just so that I can hear the woosh sound. Front mount intakes sounds louder than the engine bay placed intakes. However they are harder to install and run a risk of hydro locking your motor if you floor it through a hefty downpour. Most likely you will not be driving your BMW M4 or M3 in those weather conditions anyway, but something to keep in mind.

When purchasing air intakes, the material that these intakes are made from, matters. If you are purchasing plastic air intakes, then you will experience much more heat soak than you would from carbon fiber intakes. Usually the safe option to go with are the aluminum or carbon fiber air intakes, carbon fiber intakes being the more expensive but a better option. The image that you see above is with is made out of plastic, that's because that's only a mold for the carbon fiber intakes that were produced later and placed inside of the car. The difference between the two performance wise, was noticeable (or maybe I tell myself that to feel better about spending money on CF).

Air intake price depends on a few things:

• Front mounted or engine bay mounted
• Material out of which the intake was built
• Brand name (Eventuri Intake systems tend to cost much more than others, but are of great quality)
• Customizations

Price range: $280 - $3500

BMW M3/M4 Downpipes Mod

In the automotive world, enhancing a BMW M4 with a downpipe upgrade is a significant step towards unlocking its full potential. The factory-installed downpipes, while efficient, impose certain restrictions on the engine's ability to expel exhaust gases. Replacing these with high-performance aftermarket downpipes opens up the exhaust flow, allowing the engine to breathe more freely. This modification not only releases additional horsepower and torque but also improves the turbocharger's responsiveness. The result is a more immediate and powerful acceleration, particularly noticeable at lower RPMs.

Aesthetically, this upgrade transforms the M4's character. The sound of the engine becomes deeper and more resonant, echoing the car’s enhanced performance. This acoustic improvement enriches the driving experience, making it more engaging and thrilling, especially for those who relish the symphony of high-performance engines.

However, this transformation isn't without its considerations. Upgrading the downpipes can impact emissions compliance and may have implications for the vehicle's warranty. Therefore, it's essential for owners to weigh these factors against the benefits of improved performance and the joy of a more responsive and sonorous driving experience. This upgrade, while seemingly simple, marks a significant step in evolving the BMW M4 into a more exhilarating machine.

It is worth noting that downpipes either come catless or with catalytic converters. Catless downpipes might not be for those folks who daily drive their BMWs due to smell and/or being more loud than the ones equipped with catalytic converters. While under warranty, I avoided adding dowpipes as well as a tune, but I know many people who didn't choose my route.

Price range: $178 - $1,900

F8X BMW M3 and M4 Tuning

BMW M4 tuning is a must have for people that are looking for extra power within their vehicle. Coming from the factory, these BMW aren't tuned to their full power potential. However, this is one of the riskiest things to partake in. A bad tuner can blow your motor up and then your wallet will take a huge hit since these S55 motors aren't cheap. I would highly advise you to do very proper research on the reputation of the tuner that you choose to go with. Join Facebook groups and ask about that tuner just to make sure that your car is in good hands. The group that I recommend the most is the BMW M3 | M4 Owners Group.

If you want to be on a safer side and are ok with having a little less power, you can go with a company like Dinan or Burger Motorsports and buy their pre-set tunes of different stages. When I say a little less power, I still mean that you can get up to 122 HP increase with Dinan Stage 1 tune, and it will not cost you thousands. Current price of Dinan Stage 1 is only $599.95. Burger Tuning Stage 1 cost around $400 but will only make you gain under 60 HP.

Things to note: it is best for you to get air intakes and downpipes when you are getting your car tuned. There is a reason why all three go together in the tuner world, especially downpipes and tunes.

Price Range: $500 - $4000

BMW M3 and M4 Tires Upgrade

If you are planning on getting the combination of performance upgrades mentioned above, you MUST upgrade your tires. The tires that BMW F8X vehicles came with do not keep the car from fishtailing. If you add an additional 100+ horsepower, you best believe that your car will lose grip at any given opportunity and a sudden press on gas. Since I used to love balling on the budget and couldn't afford the Toyo R888 tires, I went with Federal 595RS-RR tires for my previous BMW M4.

Believe it or not, these tires were a true game changer in terms of the grip that I finally got. The tires were so sticky that I couldn't even do a proper donut on dry pavement with my limited donut making skills. Currently these tires run under $200 each, which is less than half of Toyo R888 tires.

Price range: $200 - $600 per tire

BMW S55 Crank Hub

One of the things that gets mentioned a whole lot with these F8X M3 and M4 BMWs is the spun crank hub. If you want to have a peace of mind, you might want to get it replaced by a reputable shop. S55 crank hubs are not very cheap and they do break. However, unless you are planning on tuning your car or are constantly pushing its limits, you might not even need one. I haven't replaced S55 crank hub on any of my M4s and yet to have an issue.

Price range (part): $710 - $1495

Labor cost range: $1000 - $3000 (depending where you go, dealerships will charge you the most usually)

BMW M3/M4 Charge Pipes

In a BMW M4, charge pipes are vital components that transport compressed air from the turbocharger to the intercooler, and then to the engine. They play a key role in cooling the air, making it denser and more oxygen-rich for efficient combustion. Upgraded charge pipes, typically made of more durable materials like aluminum, offer improved durability and efficiency. They can withstand higher pressures and temperatures, reducing the risk of damage under high performance. These enhancements can lead to better engine performance, including increased horsepower, torque, and improved throttle response, making them a favored upgrade among performance car enthusiasts.

The original charge pipes are made out of plastic that's not very durable, therefore many of them fail.  If your BMW M4 or M3 is tuned, then the likelihood of charge pipes failing increases significantly. It is not a bad idea to replace them with either aluminum or carbon fiber charge pipes. If you are building a show car, then it might not hurt to spend some extra money for a "cooler design" looking set of charge pipes.

Price Range: $129 - $1050

BMW M3 and M4 Mods Conclusion

As you can see, many options exist when shopping for BMW M4 mods or BMW M3 mods. The F8X platform has great aftermarket support, and there is no shortage of mods available, brand new or used. There are numerous Facebook groups and online forums where you can find what you need, and drivers who own these cars are super active. I wish you the best of luck building your dream spec, M3 or M4. As always, drop me a line if you have any questions or suggestions; I'd love to hear from you.