G26 Tuning
BMW's 430i Gran Coupe, M440i Gran Coupe, 2022–2026. Powered by the B48/B58 engine family.
Stage pricing for the G26
Cooling, downpipe, fueling — the ceiling worth chasing on factory turbos.
Build this stage Stage 2 methodologyBigger fueling, often a hybrid or Phantom turbo. Per-car.
Build this stage Stage 3 methodologyThe Gran Coupe is the quiet sweet spot of the 4 Series: it wears the coupe's lower, sleeker lines but adds four frameless doors and a practical hatchback, so you get the look without the two-door compromise. Underneath it's pure G22/G20 — the M440i's B58 (382 hp) or the 430i's B48 (255 hp) — tuning the same way (see the G20 page; current-gen locked-ECU notes on the G42 page).
For a lot of buyers it's the smartest pick in the family: nearly the coupe's style, nearly the sedan's practicality, and the exact same willing six to build. The honest notes are the usual B58/B48 items (the oil-filter-housing gasket; G20 page).
So the G26 is the 4 Series for people who want the shape *and* the doors — the gran coupe that quietly does both jobs, on the engine that does the rest.
Parts that fit the G26
DR Forged wheels for the G26
Custom, made-to-order forged wheels — built to your car's spec, so any of them fits the G26. Pick the look; we build the fitment.
Tech essays for the G26
Tuning and Your Warranty: What's Reversible, and What's Actually Detectable
The honest version of the warranty question — what Magnuson-Moss actually says, what we flash back before a dealer visit, and what...
ReadUpgraded Stock-Frame Turbos: Response vs. Max Power — Why We Build Two
Why we build two upgraded stock-frame turbos: Stage 1 for response and driveability, Stage 2 for maximum power from the stock frame...
ReadB48 Tuning Guide: Stages, Supporting Mods, and What Actually Holds Up
The definitive B48 platform reference for BMW and MINI owners: what each stage changes, which supporting mods Stage 2 needs, when the...
ReadFEMTO & the Bosch DME Lock Guide for BMW & MINI
When it comes to tuning modern BMW and MINI vehicles, enthusiasts have encountered significant challenges starting with the 2020+ models. Bosch's updated…
ReadUpcoming events
Cars & Coffee Delray Beach
Cars & Coffee Miami — Jungle Island Father's Day
Supercar Sundays Florida — Father's Day Car Show
Set the G26 as your garage vehicle and the rest of the store filters to what fits it.
Set vehicleBefore you tune.
Will my dealer flag the tune at service?
The bootmod3 flash is non-destructive and reversible. Revert to stock before a dealer appointment and the ECU is back to factory in a few minutes; re-flash after service. We document the revert step in writing so the next person opening your file knows what's there.
Is it safe for the engine?
Every tune we ship has been datalogged on the car it was written for. We look at knock counts, fuel trims, boost behavior, and intake temps before we sign off. If the numbers don't sit right, we revise. That review and the revision policy are built into what the tune costs.
How long until I have a working tune?
Most calibrations turn around in a few days. We log, review, and revise before anything ships — we would rather get it right than get it out fast.
Can I go back to stock?
Yes. bootmod3 supports a stock revert that returns the ECU to factory calibration in under five minutes. The flash is non-destructive — nothing in the BMW DME is permanently modified. Most owners revert before trade-in.