BMW 135i 235i 335i 435i N55 2011 – 2015

Tommy Munro • December 2, 2022

Stock 300 – 310bhp / 255 – 368whp /  500nm 

 

Stage 1 360 – 380bhp / 305 – 320whp/ 600nm

Stage 1 Options (Requires only Engine Mapping)
  •  Engine Mapping 
  • Gearbox XHP Software  (Not Required)


Stage 2 380 – 400bhp / 320 – 340whp 650nm 

Stage 2 Options (Exhaust Modification Required)
  •  Engine Mapping 
  • Gearbox XHP Software  (Recommended)
  • Decat Downpipes 

 

BMW’s Second generation of turbo charged 3.0 litre inline six engines… The N55, This engine can be found in a few variations from early E series cars with the vacuum controlled turbo, the F series *35i models which can come in either pwg (vacuum) or ewg (electronic wastegate) and also the OG M2 which is benefitted from forged crank, uprated oil pump, piston rings and additional cooling hence being capable of making more power than other N55 stage 1 or 2.

For track use a baffled sump is recommended for the *35i to prevent oil starvation, common modifications include better spark plugs (ngk 97506), stronger charge pipes & more efficient intercoolers. The different turbos used between EWG and PWG affects power when tuning usually by around 20hp with the PWG models making more. EWG is usually found from 2014 onwards and can easily be checked by looking down the left side of engine with bonnet open.

When tuning two limitations are usually found, firstly the spark plugs if they are worn and secondly the HPFP. When looking to get over 400 bhp its common to fit a dorsch hpfp or hpfp from the b58 (although the install is not as clean as the dorsch) with either of these pumps fitted ethanol blends are also capable and if an uprated turbo is installed, boost can be increased without fuel pressure crashes.

 When mapping we are able to recalibrate sports dials, disable cold start, modify burbles on sport mode and remove speed limiter





n55

 

Stage 1 remap requires no physical changes to be made to the car this is software only and sees a huge gain in performance from standard power.

 

Stage 2 remap requires exhaust modifications, whether sports cat or decat. At this power gearbox mapping is recommended also. 

m135i black
fuel pump

Stage 3 packages consist of upgraded HPFP (high pressure fuel pump) usually in the form of a Dorsch or a later B58tu pump and a hybrid turbo such as a pure turbo. With the addition of methanol or ethanol we are seeing north of 600 bhp comfortably on these cars.

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