The JB4 tuner delivers real-world gains - up to +100whp and +100wtq - on stock M178 engines. Plug-and-play in under 60 minutes; no dealer visit, no coding, no VIN lock.
8 preloaded maps via JB4PRO app: performance, valet, economy, ethanol
Fully supports 95 RON, E85, race fuel and water-methanol injection
Real-time logging, fault code read/delete, boost-by-gear, exhaust flap control
UK-fit verified: right-hand drive compatible, built in USA, 5-year warranty
