BMW 135i Mods: The Top Performance Enhancements For Your Ride

If you own a BMW 135i, you’re already familiar with the thrilling performance these compact BMWs deliver right off the showroom floor. With their turbocharged inline 6-cylinder engines producing over 300 horsepower from the factory, the BMW 135i offers unbelievable acceleration and handling capabilities for the size.

But what if you want even more power, sharper handling, and a unique style to make your 135i truly one-of-a-kind?

There are countless modifications you can make to extract more horsepower, improve handling dynamics, and customize the aesthetics of your BMW 135i. From basic bolt-ons to extensive turbo upgrades and tuning, the possibilities are endless.

In this comprehensive guide, we’ll cover the most impactful BMW 135i performance mods and customizations to take your 1-series to the next level, both visually and in terms of sheer power and driving dynamics.

We’ll specifically look at:

Power adders: Tuning, turbocharger, and supporting mods to substantially boost horsepower and torque
Suspension upgrades: Lowering springs, coilovers, sway bars and more for razor sharp handling
Braking mods: Big brake kits and performance pads for repeated, fade-free stopping power
Wheels, tires, and exterior styling enhancements: Give your 135i an aggressive new look
Interior styling: Custom shift knobs, gauges, pedal covers and more

By the end, you’ll have a complete roadmap of modifications to unlock your BMW 135i’s true performance potential and stand out from the crowd. Let’s get started!

A Closer Look at the BMW 135i and Its Performance Capabilities

First, it’s helpful to understand the factory specs of the BMW 135i to appreciate where key opportunities exist for aftermarket upgrades.

The top-level 1 Series performance model, the BMW 135i debuted in 2007 powered by a twin-turbo 3.0L N54 inline 6-cylinder engine. In 2012, BMW replaced the N54 with the updated N55 turbocharged 6-cylinder.

Both engines deliver exceptional performance:

300 to 320 horsepower at stock
300+ lb-ft of torque from just 1200 RPM
0-60 MPH in 4.7 seconds with the optional dual clutch transmission
Electronically limited top speed of 155 MPH

The BMW 135i features sophisticated, advanced engineering for the chassis, suspension, steering, and brakes considering its compact size.

As you can see, the BMW 135i delivers sports car levels of performance straight from the factory. However, there are always opportunities to improve power output, handling dynamics, braking, and aesthetics through careful modifications.

Now let’s look at the top ways to unlock even more performance from your 135i.

Power Adders: ECU Tuning, Turbo Upgrades, and Supporting Mods

When looking to substantially boost horsepower and torque output from your 135i, you need to start with the engine. There are several key mods that work together to increase power:

ECU Tuning

An engine control unit (ECU) tune is the very first modification you should get for your 135i. A proper ECU tune will optimize the factory engine mapping for your specific vehicle and mods. The results are immediate horsepower and torque gains:

30 to 80 HP increase from just a tune depending on other mods
Improved turbo response and power delivery
Smoother idle and optimized fuel efficiency

A tune prepares the ECU and adapts it to take full advantage of further mods like intakes, intercoolers, downpipes and turbo upgrades. A proper professional tune is especially important if swapping the turbochargers.

So ECU tuning is essential to extract all the performance from your 135i while optimizing drivability and engine longevity.

Turbocharger Upgrades

The heart of the BMW 135i performance is in its twin turbochargers. Since the stock turbochargers leave a lot of power on the table, one of the most impactful upgrades is installing larger aftermarket units.

Larger turbos increase power in two ways:

They flow more air by being capable of higher boost levels
The compressors have higher efficiency at high RPM to continue making power

With the right supporting modifications, upgraded 135i turbos can reliably increase horsepower by over 100 HP:

Pure Turbo, Garrett GT and other ball bearing turbo kits add 100 to 150 HP
Must upgrade intercooler, downpipes, intake, fueling to get full gains
Proper ECU tune is critical for both performance and engine safety

While turbo upgrades require careful supporting mods, they offer massive power gains. With up to 150 additional horsepower going to the rear wheels, a turbo upgraded 135i delivers supercar-rivaling acceleration.

Supporting Power Mods

To get the most out of your new BMW 135i turbos and tuning, supporting engine upgrades are a must. Here are the most important supporting power adders:

Front Mount Intercooler: The stock 135i top mount intercooler can quickly become a bottleneck for big turbo kits. An upgraded front mount intercooler keeps intake temperatures lower to avoid power-robbing heatsoak.
Cold Air Intake: An aftermarket CAI feeds the turbos cooler outside air compared to the stock airbox system. Look for intakes with a large filter away from hot engine bay air.
Lightweight Pulley Kits: Underdrive crank, water pump and alternator pulleys reduce parasitic engine power losses for more usable power.
Downpipes: High flow catless downpipes enable the upgraded turbos to spool up faster for immediate power delivery in the low to mid RPM range.

With these well matched supporting modifications in place, you’ll realize the full performance potential of your new turbochargers, especially when combined with an ECU tune.

Exhaust System Upgrades

To finish off your 135i’s power upgrades, a high-flow exhaust system is a must. The right cat-back exhaust delivers benefits including:

Increased power – especially when paired with downpipes
Significantly improved sound – burbles, pops and exotic tone
Looks fantastic with polished quad or dual tips

For the 135i, go with a name brand cat-back exhaust like Ark, Remus, or Megan Racing. Avoid cheap no-name systems that could leak or fit poorly.

Combined together – an ECU tune, upgraded turbochargers, supporting engine mods and a new cat-back exhaust – will boost your BMW 135i’s power into supercar territory, all in a package light enough to corner like it’s on rails.

Take Performance to the Next Level with Suspension Upgrades

With the power and acceleration taken care of, focusing on suspension, handling and braking is next to maximize your 135i’s performance. The factory suspension and brakes are already capable, but can be noticeably improved with the right upgrades.

Let’s look at the best ways to get razor sharp handling and confidence inspiring braking out of your BMW 1 series.

Lowering Springs and Coilovers

One quick way to transform the handling prowess of your 135i is by installing lowering springs or coilovers to drop the ride height.

Lowering your BMW achieves a few key benefits:

Lower center of gravity for sharper handling response
Reduced body roll in aggressive cornering
Eliminates wheel gap for a more aggressive stance

For basic lowering of about 1.5 inches, sport springs are a budget-friendly option. For adjustable damping and customizable ride height, high-end coilovers systems are ideal.

KW and H&R coilovers for the BMW 135i let you dial in ride comfort and handling balance, while dropping the car 2+ inches for head turning looks.

Sway Bars and Chassis Braces

The next handing upgrades to complement lowered suspension are sway bar kits and chassis bracing.

Aftermarket sway bars (also called anti-roll bars) are stiffer than stock and reduce body lean during hard cornering for a flatter, more neutral handling. Chassis braces reinforce the chassis’ rigidity for optimal suspension performance.

For the BMW 135i, a bigger rear sway bar makes the biggest difference in reducing oversteer and improving grip during aggressive driving. A front strut tower brace also effectively stiffens the chassis against flex.

Working in unison with your lowered suspension and sticky tires, sway bars and chassis bracing take cornering performance to the next level so you can fully utilize all that turbocharged power your 135i is now making.

Sticky Tires and Lightweight Wheels

Once the suspension upgrades are handled, the next focus is grip – which comes down to tires and wheels.

The BMW 135i needs wider performance tires on all four corners to take advantage of the improved handling. Some great summer / high performance options include:

Michelin Pilot Super Sport
Continental ExtremeContact Sport
Pirelli P Zero

For even more grip at the limit, ultra-high-performance tires like the Michelin Pilot Sport Cup 2 bring race car levels of grip, but compromise comfort and treadwear.

Lightweight aftermarket wheels complement sticky new tires by reducing unsprung weight for quicker acceleration, braking and steering response.

Aim for 18 or 19 inch lightweight wheels to lower rotational mass while allowing for wide performance rubber. Flow formed and multi-piece forged wheels from HRE, BBS and Forgeline are ideal upgrades.

Brembo and StopTech Big Brake Kits

To finish off your quest for handling supremacy, upgrade the 135i’s brakes with bigger rotors and calipers from the professionals at Brembo and StopTech.

The factory bmw brakes are capable, but fall short during repeated hard cornering and track use. Improved heat capacity and cooling of aftermarket brake kits prevents fade for reliable stopping power.

For street driving, the Brembo GT brake kit with drilled rotors and multi-piston calipers offers the best balance of performance, low dust and noise – with minimal change to brake pedal feel.

With matched suspension, wheel, tire and brake upgrades, your boosted 135i will rocket out of corners and repeatedly haul down speeds with precision and control.

Exterior and Interior Styling: Take Your BMW’s Looks to the Next Level

With major power, handling and braking upgrades achieved, let’s look at exterior and interior styling modifications to complete your 135i’s transformation.

Here are the most popular visual upgrades for the BMW 135i:

Exterior Styling

To give your BMW 135i an eye catching new look, consider these exterior styling mods:

Blackout Trim – Blackout grilles, side mirrors, trim accents and badges are easy to do and look great on BMWs. Consider gloss black or a subtle matte.
New Wheels – As mentioned for performance, new lightweight wheels in an aggressive design transform the 135i’s stance.
Lowered Suspension – Dropping your 135i with coilovers or springs tightens up wheel well gaps for a lowered sports car look.
Tinted Taillights – Dark tinted lenses modernize the look of the 135i’s tail lights for a refreshed rear view profile.
Vorsteiner Aero – For a much more aggressive look, Vorsteiner makes aerodynamic bumpers, diffusers, spoilers and carbon fiber elements.

Interior Styling

Inside, popular ways to customize your BMW’s cockpit include:

Color matched gauges or A-pillar gauge pods for engine vitals
Weighted shift knobs and short throw adapters for quicker shifting
Color accents on seats, door cards, dash trim, pedals and floor mats
Alcantara or leather steering wheel and shifter upgrades

With thoughtful interior and exterior styling enhancements, you can put a unique stamp on your 135i inside and out.

By starting with the engine and working through the drivetrain, suspension, brakes, chassis, and aesthetics, you now have a comprehensive blueprint for transforming your stock BMW 135i into a Turbo straight six street racer matched to your style.

Let’s Recap: The Best BMW 135i Mods for Power, Handling and Style

To summarize this guide’s top recommendations:

Engine and Power:

ECU Tune – the essential first mod to optimize performance
Big Turbo Upgrade – over 100 HP gains with supporting mods
Intercooler – avoid heat soak and keep intake temps low
Intake – improved airflow and intake sound
Downpipes – reduced restrictions for quicker spool
Cat Back Exhaust – freer breathing, looks and exotic sound

Handling and Braking:

Coilovers – lower vehicle height, customize damping
Sway Bars – reduce body roll for flatter cornering
Wheels and Tires – lighter wheels, stickier rubber
Big Brake Kit – better heat capacity and reduced fade

Style:

Blackout Trim – dark tint on chrome elements for a custom look
New Wheels – lightweight, aggressive designs transforms stance
Lowering Springs – tighten up wheel well gaps
Shift Knobs – add color accents and improve feel
Color Accents – customize cockpit and interior accents

These modifications work together to take the BMW 135i’s performance to new heights at the street or track, all while adding your own unique style and flair.

Consult a knowledgeable performance shop during planning and installation of your upgrades to ensure reliable and well integrated mods. With the classic inline 6 turbocharged performance enhanced by technology and craftsmanship, your modified BMW 135i will deliver uncompromising speed and driving dynamics for years to come.

Conclusion

For BMW 1 series owners seeking more power and sharper handling from their 135i, this guide provided a comprehensive overview of the most impactful engine, suspension, brake, wheel, tire and styling modifications to take the BMW to the next level.

With carefully selected upgrades like bigger turbochargers, ECU tuning, sticky rubber, sway bars and chassis bracing, you can tap into the 135i’s immense performance potential and configure it to match your driving style.

While the 135i is fantastic out of the box, the aftermarket for performance parts is endless, allowing you to build a customized street racer with your own signature style. With this expert guide, you have an upgraded 135i game plan to unlock the 1-series’ full capabilities and stand out from the crowd.

Now it’s time to unleash your car’s potential.