BMW 4 Series Tuning (F32,F33 & F36)

"Thanks for reading our BMW 4 Series tuning article."

The 4 Series is a good car tuning project to play with. With the right mods your 4 Series can be transformed into an awesome motor.

Don't waste money, do your homework and follow our unbiased guides to each performance upgrade to avoid disappointment.

We look at 4 Series tuning and highlight the optimum modifications. BMW 4 Series provide a fun base for your project and with carefully chosen motorsport parts you can maximise your driving pleasure.

Tuning tips and articles

Engine tuning Transmission tuning Care care Intake & exhaust mods Improve handling Forums

Our aim in 4 Series engine tuning should be to increase peak power and Torque at the top end.

Following our guidance for modding your 4 Series you will end up with a practical sporty car that will potentially embarrass bigger cars.

Sadly with smaller engine sizes you are wasting your time spending money on modifications, so if this applies to you get yourself an engine swap then apply the following mods.

Tuning modifications.

Typically these modified upgrades are usually carried out by our members, decide how far you wish to go in your tuning project before you start.

Getting the right performance parts for your planned usage of the car is a time and money saver. Stage 3 (competition) mods just don't work well on the road and will make the car undrivable.

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Guide to the Best Tuning Mods & Upgrades

  1. Mods that Remove a Restriction

    If the intake or exhaust are restricted in any way this will have an impact on your cars performance, so use an induction kit/filter upgrade and better flowing exhaust whenever your tuning creates a flow restriction.

  2. Mods that Improve Handling

    Braking, Suspension and general alignment of the suspension components is vital for any tuning project even before you start increasing power.

  3. Fit Stronger Parts

    Tuned cars will show up weaknesses, typically in the turbochargers, clutch and internal engine components. Whilst most engines can cope with mild tuning mods, TorqueCars recommend that you upgrade the internal components before these weak spots manifest themselves.

  4. ECU Tunes & Remapping

    While some cars can be easily remapped, others may require piggyback ECU's or aftermarket ECU's but this is the most vital step of your tuning project as it fully releases the power from all of your mods and upgrades. Expect 10-20% on NASP engines and 30-40% on turbocharged units.

  5. More Power Needs More Fuel & Air

    Every tuning project will aim to increase the air supply, but fuel supply is just as vital and will need to match the air the engine can utilise. Fuel to Air ratio is vital so upgrade the fuel pump & injectors. Also you can look to perform head mods (flowing and porting), bigger valves, fast road cams and forced induction upgrades to improve fuel.

Stages of Tune

Stage 1 mods: Remap, Alloy wheels, Sports exhaust, Lighter flywheel, Panel air filter, Suspension upgrade (drop 30-40mm).

Stage 2 mods: fuel pump upgrades, Ported and polished head, high flow fuel injector, Power/Sport clutch, Fast road cam.

Stage 3 mods: Adding or upgrading forced induction (turbo/supercharger), Sports gearbox, Engine balancing, Internal engine upgrades (pistons/head/valves), Competition cam.

Petrol engines fitted to the 4 Series.

  • 418i 2016– B38A15M0
    1.5 L turbocharged I3 100kw (134hp) @4,400–6,000rpm 220 Nm (162lbft) @1,250–4,300rpm
  • 420i 2014–2016 N20B20
    2.0 L turbocharged I4 135kw (181hp) @5,000–6,250rpm 270 Nm (199lbft) @1,250–4,500rpm
    2016– B48B20A
    2.0 L turbocharged I4 135kw (181hp) @5,000–6,500rpm 270 Nm (199lbft) @1,350–4,600rpm
  • 428i 2013–2016 N20B20
    2.0 L turbo I4 180kw (241hp) @5,000–6,000rpm 350 Nm (258lbft) @1,250–4,800rpm
  • 430i 2016– B48B20B
    2.0 L turbocharged I4 185kw (248hp) @5,250–6,500rpm 350 Nm (258lbft) @1,450–4,800rpm
  • 435i 2013–2016 N55B30M0 (twin scroll turbo)
    3.0 L turbocharged I6 225kw (302hp) @5,800–6,500rpm 400 Nm (295lbft) @1,200–5,000rpm
  • 440i 2016– B58B30M0
    3.0 L turbocharged I6 240kw (322hp) @5,500–6,500rpm 450 Nm (332lbft) @1,380–5,000rpm
  • M4 2013– S55B30T0
    3.0 L twin-turbocharged I6 317kw (425hp) @5,600–7,300rpm 550 Nm (406lbft) @1,800–5,500rpm
  • M4 Comp 2016– 331kw (444hp) @7,000rpm
  • M4 CS 2017– 338kw (453hp) @6,250–7,000rpm 600 Nm (443lbft) @4,000–5,380rpm
  • M4 GTS 2016– 368kw (493hp) @6,250rpm 600Nm(443lbft) @4,000–5,000rpm

Diesel engines

  • 418d 2014–2015 N47D20
    2.0 L turbocharged I4 105kw (141hp) @4,000rpm 300 Nm (221lbft) @1,750–3,000rpm
    2015– B47D20
    2.0 L turbocharged I4 110kw (148hp) @4,000rpm 320 Nm (236lbft) @1,500–3,000rpm
  • 420d 2013–2015 N47D20
    2.0 L turbocharged I4 135kw (181hp) @4,000rpm 380 Nm (280lbft) @1,750–2,750rpm
    2015– B47D20
    2.0 L turbocharged I4 140kw (188hp) @4,000rpm 400 Nm (295lbft) @1,750–2,500rpm
  • 425d 2014–2016 N47D20O1
    2.0 L twin-turbocharged I4 160kw (215hp) @4,400rpm 450 Nm (332lbft) @1,500–2,500rpm
    2016– B47D20O1
    2.0 L twin-turbocharged I4 165kw (221hp) @4,400rpm 450 Nm (332lbft) @1,500–3,000rpm
  • 430d 2014– N57D30O1
    3.0 L turbocharged I6 190kw (255hp) @4,000rpm 560 Nm (413lbft) @2,000–2,750rpm
  • 435d xDrive 2014– N57D30T1
    3.0 L twin-turbocharged I6 230kw (308hp) @4,400rpm 630 Nm (465lbft) @1,500–2,500rpm

Your targets when tuning the engine should be a nice flat torque band. You want to avoid sending all the power to be at the top end of the rev range unless you are creating a motor sport car.

The point of our guides is to give a limited introduction of tuning upgrades and point you in the right direction, our forum is best place to go if you need more detailed advice and tips on your car tuning project, the best motorsport upgrades and all aspects of modding cars.One of the most cost effective mechanical parts you can do on your NASP engine is to fit a fast road camshaft .

The exhaust & intake flow play a large part in your cars power band, but be careful here, getting this wrong can upset the idle and make the car hard to drive in traffic. You'd need to follow a camshaft upgrade with other mods and finish with a performance chip to fully release the power gain.

When pushing up the power you will need to ramp up to the fuelling. More power needs more fuel.

If you find you suffer from flat spots and surges after your uprated kits you should check the fuelling and try a higher octane fuel as well. Upgrading the injectors is another beneficial modification and will deliver sufficient fuel.

A fuel pump will only deliver a finite amount of fuel, so you may need to uprate this if your injectors are demanding more fuel.

Intake and Exhaust Tuning.

The next area for modification is the intake and exhaust. Air induction kits will only help to add performance if the air intake is struggling!

Remus make a good range of exhausts for BMW and they have now released an option for most 4 series engines.

We highly rate Akrapovic, Dinan and Corsa exhausts. The OEM particulate filter is not that well designed, and can be improved with a carefully designed larger bore aftermarket system.

Adding an induction kit to most stock engines will see LITTLE LOW END POWER GAIN AT ALL. If you have heavily modified your engine and it's need for air INCREASES DRAMATICALLY then an induction kit is the answer and will help remove this restriction.

Derestricting the airflow into the engine is the primary part of car tuners so get a better flowing air filter if you find that the car is running lean only if you find the car is running lean. Induction kits can sound sporty but due to the warm air in the engine bay they will not add noticeable power and more often than not rob you of power on most cars.

Do not go with the widest exhaust you can find this will reduce the exhaust flow rate - the best exhausts for power gains are usually between 1.5 to 2.5 inches. It is the shape and material more than the bore size.

Head porting and polishing the head will allow you to maximise your air/fuel charge. Leave this to a professional though with a proper flow bench and machine tools Your clutch can fail as you increase the power if it starts to slip and the standard clutches are only ever good for power gains of up to 45%. Fit a competition clutch to avoid power losses through the transmission. The best mods in our opinion for your 4 Series are a remap especially on a turbo, a fast road camshaft and sports exhaust, with a good air intake.

NASP engines do not achieve big power gains if you remap them, unless you have done extensive modifications. With turbocharged engines this is another story. A remapped turbo will give impressive power gains and take full advantage of the strength of the block. The most significant power gains for NASP engines usually involve the addition of forced induction. Turbos are generally harder to add than a supercharger. With a turbo the boost curve is related exponentially to the engine speed making it more challenging to map.

Superchargers, however will give a boost which is directly proportional to engine speed so is easier to map. Adding forced induction will generally require a lower compression ratio or water injection.

Handling/Suspension upgrades

Many 4 Series owners uprate the handling of their cars with tuning suspension upgrades as a priority, this will certainly increase your enjoyment of the car.

Good suspension tweaks that often improve handling for the 4 Series include a couple of degrees negative camber and 1-1.5 degrees of toe out on the front wheels.

Coilovers make good sense, especially if you have a wide range of adjustment on them, and can set the ride height to suit your preferences. The H&R spring lowering kit for the 4 series is very well designed and put together.

The coilovers from BC racing offer around 30 settings, and are probably the best value 4 series upgrade out there. Look also to the KW Varient 3's and we've even seen some air suspension kits already appearing, notably the one from airrex but we've not been a fan of air suspension from a performance point of view, but offers a range of aesthetically pleasing settings, so it will suit those more into the look of the car.

Brake upgrades make sense, with many upgrading non M series models to the M series brakes. The 370mm front discs make a big difference over the smaller OEM originals. It's worth noting that many models have the same 4 pot calipers as the M sport, but come with 340mm discs but you'll still need to swap the calipers to carry the length difference.

We suggest that you fit modified suspension and lower the car by 26mm - 35 mm. Larger drops require arch work - especially on models already equipped with motorsport suspension.

Alloy wheel upgrades.

Alloy wheels will help the brake cooling and are usually lighter than steel ones. If you are serious about performance then you will need to carefully choose your tyres - ideally with a directional tread pattern tyre.

The following are not exhaustive, but are tyres that 4 series owners have fitted and rate highly.

  • Michelin Pilot Super Sport Tires
  • Toyo Proxes T1 Sport Tires
  • Hankook Ventus V12 Evo2 Tires

Please note although they can look cool on the 4 Series big alloys will actually decrease your performance. The larger you go the lower your acceleration will be - this to the change in your effective final drive ratio.

For this reason we would advise sticking to a maximum wheel size of 18 inches, although we know some of our members have installed larger rims with no problems.

There is a more updated version of this BMW 4 Series Tuning article on

For more information on Tuning your car please join us in our friendly forum where you can discuss 4 Series options in more detail with our 4 Series owners. It would also be worth reading our unbiased BMW tuning articles to get a full grasp of the benefits and drawbacks of each modification.

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