Tuning the BMW 4 Series Tuning (F32,F33 & F36)
"Thank you for reading my BMW 4 Series tuning article."
We look into 4 Series tuning and provide tips on the optimum modifications. BMW 4 Series make awesome project cars and with the ultimate enhancements you can dramatically enhance your driving enjoyment.
The 4 Series is a good car modification project to carry out. If you do your planning then you can create an awesome 4 Series but don't be fooled there are lots of tuning modifications out there that will simply not suit it read our unbiased guides first.
Handling/Suspension upgrades
Many 4 Series owners uprate the handling of their cars with tuning suspension mods as a priority, this will certainly increase your enjoyment of the car.
Good suspension tweaks that substantially benefit handling for the 4 Series include a couple of degrees negative camber and 1-1.5 degrees of toe in or out on the front wheels. Toe in for stability, or Toe out to improve cornering. It would also pay to improve the brakes, by adding larger discs and or higher friction pads..
Drop the car by as much as 26mm - 43 mm. and fit motorsport grade stiffer dampers, bigger drops will need other modifications in most instances.
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.
Turning our attention to the engine we need to get a bit more torque out of the top end.
All turbo and especially diesel engines are crying out for a remap, you'll hit 30% more power with the right map/engine setup and should also get improve fuel economy.
BMW really have made an awesome car in the 4 Series, it looks stunning, performs well and ticks most boxes for even the most discerning driver.
Engine tuning mods.
These are the sports kits are usually installed by our members, decide how far you want to push your car before you get going.
- 418i 2016– B38A15M0
1.5 L turbocharged I3 100kw (134hp) @4,400–6,000rpm 220 N⋅m (162lbft) @1,250–4,300rpm - 420i 2014–2016 N20B20
2.0 L turbocharged i4 135kw (181hp) @5,000–6,250rpm 270 N⋅m (199lbft) @1,250–4,500rpm
2016– B48B20A
2.0 L turbocharged i4 135kw (181hp) @5,000–6,500rpm 270 N⋅m (199lbft) @1,350–4,600rpm - 428i 2013–2016 N20B20
2.0 L turbo i4 180kw (241hp) @5,000–6,000rpm 350 N⋅m (258lbft) @1,250–4,800rpm - 430i 2016– B48B20B
2.0 L turbocharged i4 185kw (248hp) @5,250–6,500rpm 350 N⋅m (258lbft) @1,450–4,800rpm - 435i 2013–2016 N55B30M0 (twin scroll turbo)
3.0 L turbocharged I6 225kw (302hp) @5,800–6,500rpm 400 N⋅m (295lbft) @1,200–5,000rpm - 440i 2016– B58B30M0
3.0 L turbocharged I6 240kw (322hp) @5,500–6,500rpm 450 N⋅m (332lbft) @1,380–5,000rpm - M4 2013– S55B30T0
3.0 L twin-turbocharged I6 317kw (425hp) @5,600–7,300rpm 550 N⋅m (406lbft) @1,800–5,500rpm - M4 Comp 2016– 331kw (444hp) @7,000rpm
- M4 CS 2017– 338kw (453hp) @6,250–7,000rpm 600 N⋅m (443lbft) @4,000–5,380rpm
- M4 GTS 2016– 368kw (493hp) @6,250rpm 600 N⋅m (443lbft) @4,000–5,000rpm
Diesel engines
- 418d 2014–2015 N47D20
2.0 L turbocharged i4 105kw (141hp) @4,000rpm 300 N⋅m (221lbft) @1,750–3,000rpm
2015– B47D20
2.0 L turbocharged i4 110kw (148hp) @4,000rpm 320 N⋅m (236lbft) @1,500–3,000rpm - 420d 2013–2015 N47D20
2.0 L turbocharged i4 135kw (181hp) @4,000rpm 380 N⋅m (280lbft) @1,750–2,750rpm
2015– B47D20
2.0 L turbocharged i4 140kw (188hp) @4,000rpm 400 N⋅m (295lbft) @1,750–2,500rpm - 425d 2014–2016 N47D20O1
2.0 L twin-turbocharged i4 160kw (215hp) @4,400rpm 450 N⋅m (332lbft) @1,500–2,500rpm
2016– B47D20O1
2.0 L twin-turbocharged i4 165kw (221hp) @4,400rpm 450 N⋅m (332lbft) @1,500–3,000rpm - 430d 2014– N57D30O1
3.0 L turbocharged I6 190kw (255hp) @4,000rpm 560 N⋅m (413lbft) @2,000–2,750rpm - 435d xDrive 2014– N57D30T1
3.0 L twin-turbocharged I6 230kw (308hp) @4,400rpm 630 N⋅m (465lbft) @1,500–2,500rpm
Getting the right sports modifications for your planned usage of the car is vital. Stage 3 (competition) mods just don't work well on the road and will make the car undrivable.
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How to tune your car
- Improve the handling
Focus on Suspension improvements, such as coilovers and make sure the bushings are in good order and that the alignment is correct. Then focus on improving the brakes, with a big disk brake conversion kit and fast road brake pads.
- Remove restrictions
Focus on the intake and exhaust with filters being the common point of restriction in a tuned car. Intercoolers may also become restrictive on turbo engines so this may also need to be uprated.
- Burn more fuel & air
Increase the fuelling so it matches the air coming into the engine. The ratio is important so you need to improve the fuel pump and injectors, so the head mods, big valve conversions, fast road camshafts and forced induction upgrades extra supply of air is adequately met.
- Test and replace any weak parts
Weak areas are commonly the clutch, the turbocharger and pistons and crankshaft in a highly tuned engine. Makes sure these components will cope with your power aspirations.
- The Tune or Remap
A cars ECU controls the fuel, timing, spark and even the turbo in some cases, so to fully extract your gains you should remap the car last and this will fully release the power. Some cars are easy to map, and others require piggyback ECU's or aftermarket ECU's but this is the most vital step of your tuning project.
Modifying to Stage 1:
Panel air filter, Sports exhaust, Remap, Suspension upgrade (drop 26mm - 43 mm.), Lighter flywheel, Alloy wheels, intercooler.
Modifying to Stage 2:
Ported and polished head, high flow fuel injector, Fast road cam, Power/Sport clutch, fuel pump upgrades.
Modifying to Stage 3:
Sports gearbox, Competition cam, Internal engine upgrades (pistons/head/valves), Engine balancing, Adding or upgrading forced induction (turbo/supercharger).
You need to keep as much low end power as possible and aim to get a wide power band rather than a narrow top end power hike.
The point of our tips is to give a limited introduction of modifying performance parts and point you in the right direction, our forum is the place to go for detailed advice and tips on your car tuning project, the best uprated kits and all aspects of modding cars.A fast road cam usually proves to be one of the best NASP power mods you can do with a single part fitted to your engine.
The intake and exhaust durations play a huge factor in your cars power band, but be careful here, getting this wrong can upset the idle and make the car challenging to drive in traffic. You'd need to follow a camshaft upgrade with other mods and finish with a reflashed ECU for the best performance gains.
You will need to ensure that the engine is not starved of fuel so will need to ramp up the fuelling.
If you find you suffer from flat spots and power surges after your motorsport mods you should check the fuelling and try a higher octane fuel as well. To get sufficient fuel you may need to upgrade the injectors on your engine.
Uprate the fuel pump to cope with the extra fuel requirements of your tuned 4 Series's uprated injectors.
Intake and Exhaust Tuning.
Breathing mods are usually next up. Contrary to popular belief there is generally very little if any power gain reached by fitting an induction kit, they only help and are recommended after you boost the engines power to the point where the standard air intake box cannot cope!
Maximum power gains come from a full induction kit with a cold air feed on heavily tuned engines, this can be sited within an air box but a panel filter should suffice for most applications. TorqueCars suggest you use a panel air filter as these are easy to clean and maintain and generally perform better than paper ones.
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.
Sports exhausts can usually air flow from the engine but do not go too big or you may end up will reduce the flow rate. Stick to 1.5 to 2.5 inches as a rule of thumb.
Polishing and porting 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 When you heavily modify your 4 Series you will see that the standard clutch starts to complain so get an uprated clutch. The best mods we would do for your 4 Series are fast road camshaft, remap, induction and exhaust, suspension.
Remaps offer phenomenal power gains on all turbo charged cars. On NASP engines the benefits are doubtful. However a remap on a NASP engine will help unleash the potential if you have done a lot of mods. The most phenomenal power gains for NASP engines usually involve the addition of forced induction. It is generally simpler to bolt on a supercharger than it is to fit a working turbo. It is difficult to map fuelling with a turbo as the boost comes on exponentially with revs.
Superchargers, however will give a boost which is correlating to engine speed so is easier to map. To cope with forced induction you will usually need to decrease the engines compression ratio .
Alloy wheel upgrades.
Because alloy wheels are lighter they improve performance and they help to cool the brake disks. If you are serious about performance then you will need to carefully choose your tires - ideally with a soft compound tire. Large 4 Series alloy wheels can decrease performance. If you get big alloy wheels you will be changing your final drive ratio.
With this in mind we would advise sticking to a maximum wheel size of 18 inches, although we know some of our members have fitted larger wheels with no problems.
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.
Tyre choices are important, the car needs all the grip it can muster, and tends towards being a little tail happy even in standard tune.
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
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