Where the modern BMW scene began
The E9x 335i introduced turbocharging to the mainstream 3 Series, and the N54 turned out to be one of the most tunable engines BMW ever built - forged from the factory, twin turbos, and happy at double its stock output with supporting hardware. Nearly twenty years on, the platform is a modern classic: cheap to buy, endlessly documented, with a parts catalogue that covers everything from big-power builds to the service items that keep high-mileage cars honest.
The proven upgrade path
E9x - frequently asked
N54 or N55 - which 335i do I have?
Pre-LCI cars (2006-2010) run the twin-turbo N54; from 2010 the single twin-scroll N55 took over. They tune differently and share little engine hardware - every listing here states which it fits.
How much power will a stock-turbo N54 make?
With downpipes, intercooler and a good map, 380-420hp is routine on pump fuel - the factory forged internals are the reason the engine's reputation exists. Beyond that you're into turbo upgrades.
Do you cover the E9x M3?
Yes - intake, exhaust, suspension and braking for the S65 V8, plus the service and reliability parts (rod bearings among them) every owner should have on the list.
Do you offer ECU tuning in-house?
Yes - Stage 1-3 and custom ECU mapping are done fully in-house. We don't currently offer parts fitting, but we're happy to advise on your install.