Had a good friend Sam West down at MotoHub in Stoke offer me a dyno slot to do some power runs on the 2025 V4S. The plan was to back to back the stock exhaust and stock map with the Arrow slip on and associated arrow road map from the Termignoni Upmap. (As most will know mapping the new V4 isn’t really an option yet due to restrictions on the ECU) So, my bike does have a dry clutch conversion but apart from that no engine mods. Sprint filter was left in for both runs and the bike was still on its Supercorsa road tyres. Both exhausts had about 5/6 runs once warmed up. Stock exhaust and stock map : Max 208.15bhp (at the wheel) Arrow Exhaust with Upmap: Max 215.3bhp (at the wheel) For comparison on the same dyno my 2023 V4S track build with Storm exhaust fully mapped by Sam with Woolich pulled 206bhp at the wheel. The Upmap disables the exhaust servo and requires the lambdas to be disconnected. And at parts of the rev range the difference in bhp was just over 10bhp more that stock The arrow isn’t deafeningly loud but I’ve already been black flagged with the stock exhaust at donington there’s not much hope of me using the arrow anywhere but abroad. Roll on Aragon next month
