Introduction
Under the hood the 440i boasts the B58 engine, a turbocharged flat 6 engine that is one of BMW’s greatest modern engines. Other BMW cars such as the 340i and M240i among others also feature this powerhouse underneath the bonnet. Due to the engine’s reliability and tunability, you can extract extra power from your 440i with ease!
While primarily covering engine tuning in this article, we will also look at upgrades you can make to your suspension to make the handling sportier and give your Beamer a better stance.
Performance Exhaust
Adding a performance exhaust to the 440i can unlock a whole new level of fun from the car.
First, the performance boost. A performance exhaust system offers reduced exhaust back pressure, leading to increased horsepower and torque throughout the rev range.
In a car like the 440i, that already performs so well, this bring about a perceptible difference on the throttle response making accelerating effortless.
Now, let’s talk about the auditory benefits. The sound of the car is arguably one of the most important features for enthusiast owners. A sports exhaust system on a BMW 440i presents a more aggressive, deeper growl in comparison to the stock exhaust.
This allows you to hear that lovely sounding inline 6 engine a lot better when you’ve got the foot down.
You have some different options for the exhaust depending on your budget and goals. For example, if you are mainly after additional sound then you may only want to upgrade the backbox/cat-back. Where as if you are solely after maximum performance gains then you may want to start by replacing sections of the exhaust closest to the turbo like the downpipe.
The downpipe should be the first port of call if you are wanting to unlock some performance. This will help the engine breathe better. Installing a downpipe may produce a CEL but this can be mapped out by your tuner when you are getting it mapped (you should for maximum gains).
With the downpipes, you generally have the option of a decat or high flow sport cats.
The decat option will give you the best performance however won’t be road legal.
High flow sports cat’s are less restrictive than the standard catalytic converters while remaining road legal. Sports cats are the preferred option by most owners.
Cobra Sport offer an upgraded downpipe with the option of either a decat setup or a sports cat setup.
If you have upgraded the downpipe and to sport cats, then the majority of the gains from the exhaust have already been unlocked. To really maximise performance (and increase sound) then you can look at removing the resonator and opting for an aftermarket backbox/cat-back. Just be aware that opening the exhaust up too much can increase the sound quite substantially.
Induction Kit
Let’s talk intake mods!
The factory intake setup on theses cars is well optimised from the factory and as such you won’t see significant performance gains from aftermarket intakes.
That doesn’t mean you can’t get significant intake sounds from them though! There are high quality kits out there that can really help you hear the turbo and induction sounds on the 440i.
The MST enclosed intake is a good example of this. This intake replaces the OEM intake with an aftermarket one and produces some really nice turbo sounds.
If you are after purely performance gains and aren’t fussed too much about intake sounds, then you can put a performance panel filter into the OEM airbox. This is cheaper than an entire aftermarket induction kit and can actually produce marginally better gains.
MST Intake
For the BMW 440i
Remap
The remap is the holy grail of performance mods on these cars.
The B58 engine responds very well to tuning, allowing you to unlock a vast amount of horsepower and torque.
Alongside the power hike, you will find the driveability of the 440i to be much better. Reduced turbo lag and an improved throttle response makes daily driving so much easier with power available on tap throughout the revs. Depending on the tuner and the other mods you have, you can also have the power delivery altered to make it smoother or more aggressive.
In terms of value for money, a remap alone is one of the best performance mods for the 440i’s.
In fact, a remap alone can unlock around 75hp! This takes the power output to around 400hp. Just from a remap! This is assuming that the engine and turbo are all in good condition.
Even more power is available after remapping if you have fitted other induction and exhaust modifications.
If you have fitted other mods such as a downpipe, then it would be silly to not have the car remapped after. Remapping after the other mods have been installed allows your tuner to recalibrate your ECU to make the most of these mods and the increased air flow.
Turbo Upgrade
A turbo upgrade can significantly propel the performance of a BMW 440i to new levels. This is one of the more expensive performance mods and will require supporting modifications so ensure you budget for this.
The Pure Turbos upgraded turbo tends to be on of the most popular options on the 440i for owners looking for serious power.
With this turbo, you can expect an easy 560whp (yes wheel horsepower) on standard 93 octane fuel with the potential for more on E50/Meth. With premium 98 octane fuel you can expect over 600whp with supporting mods.
To have your turbo upgraded, you need to send them your standard turbo to be modified and upgraded. They also offer a deposit option if you can’t send them your turbo right away.
As with the majority of turbo upgrades on cars, supporting mods are required to maximise the turbo’s potential and maintain reliability.
Some of the supporting mods can include:
- Downpipe + sports cat/decat
- Custom tune/remap
- Upgraded fuel pump
- Fuel-It charge pipe injection (CPI) kit
You should speak to the turbo manufacturer or your tuner to see what exact supporting mods they recommend.
Coilovers
We’ve spoke about increasing the power output, not let’s touch on improving the handling and enhancing the suspension.
The installation of coilovers on the 440i presents a multitude of striking performance and aesthetic benefits. At the heart of these enhancements is the superior handling and adaptability that coilovers provide.
With coilovers, you can manually adjust the suspension settings and height enabling you to refine your ride quality and handling. This allows you to set your suspension up for sportier driving and can enhance your car’s abilities to tackle corners and remain stable during high speed manoeuvres.
Whether you’re cruising city streets or tackling winding backroads, this modifiable flexibility caters to each scenario, delivering a ride that is smooth and responsive.
You have different options, with KW and Bilstein offering popular sets.
One of the main concerns by owners looking to fit coilovers on a comfortable car like 440i is losing that ride quality.
KW Street Comfort coilovers are a good option that gives you the benefits of a sporty adjustable suspension while retaining the comfort and ride quality the car boasts in standard form.
These coilovers have been designed with prolonged road use in mind and as such have been engineered to maintain comfort around town, on the motorway and in a variety of daily driving environments.
If you are just looking to drop your ride height and aren’t concerned about the adjustability of your suspension, then you could look into lowering springs which are more budget friendly.
Direnza Lowering Springs
For the BMW 440i
Stance Coilovers
For the BMW 440i
Finishing Thoughts
So there you have it! The best proven performance mods for the 440i.
It isn’t an exhaustive list, and that’s because the B58 engine is already set up efficiently from the factory.
The best bang for your buck mod is without a doubt a remap. This alone can unlock more power than fitting all the other physical intake and exhaust mods (except an upgraded turbo!).
If you are considering a remap, have a think about whether you want to add a free flowing exhaust in the near future. If so, maybe hold out and add the exhaust first and then have it mapped. This will lead to much better gains having your 440i remapped after the other mods have been installed.
Happy modding!
