740i B58 Stage Roadmap
Tuning roadmap · 2017 BMW 740i · G11 / G12

B58 build plan, stage by stage

326→750hp

What to fit at each stage, in order, and when it is safe to move on. Tick parts off as you go — your checklist is saved in this browser.

Engine
B58B30M1 · 3.0 inline-6 turbo
Stock output
326 hp · 450 Nm
ECU
Bosch MG1 · unlock needed
Gearbox
ZF 8HP automatic
Kerb weight
≈ 1,850 kg

Power at each stage

Typical crank figures on Kenya's best pump fuel — 95 RON Super. Genuine 98 RON and any ethanol/race-fuel blend aren't sold at Kenyan pumps, so Stage 2+ and beyond assume fuel brought in specially (drums of ethanol/race fuel, or a methanol kit).

Factory Power up to the low end Typical range for the stage

The steps

Do the parts first, then the tune, then datalogs. Don't skip a stage without logging.

Rules for every stage

Log everything

Check timing corrections, fuel pressure and intake temps after every change before adding more.

Fuel decides the ceiling

Kenyan pumps top out at 95 RON Super — no 98 RON, no E85, no flex-fuel. A strong Stage 2 is the sensible stop unless you're willing to bring in ethanol or race fuel by the drum.

Keep it road legal

A catless downpipe will fail an NTSA inspection and makes for a very loud, very visible target at a checkpoint. Use a catted one for road use.

Tell the insurer

Declare all modifications, and expect the powertrain warranty to be void once the car is tuned.