Aprilia Tuono Factory Big Bore Dyno

This is a Tuono built 2 years ago in the AF1 Racing performance shop. The engine was heavily modified. Base mapping in stock ECU is "map 2" variant of stock OEM mapping. Additional fuel mapping was done via Power Commander PCIIIusb. Pistons are 100mm displacing 1060cc and sliding in Nicasil bores re-plated by Millennium Technologies at a clearance of .0025 inches. Camshafts are stock but timed to precisely 106/109 lobe centers. Heads were mildly ported by me to clean up areas around valve seats. Compression ratio is stock, and squish clearance is .9mm since this is primarily a street use engine with regular track days thrown in too. Throttle bodies are stock 57mm units but intake stacks from the Aprilia RSVR are used since they are 60mm shorter and provide a smoother top end power band in this application. On the cold side air is filtered through a stock paper element filter and the airbox is modified with the Evo open top kit. Fuel injectors are stock but duty cycle is over 90% above 8,500 rpm, larger 622cc injectors up from the 403cc stockers will be used on the next 1060 build I do. fuel pressure is stock at 48psig. Flywheel weight has been removed. Spent charge is exiting through an Akrapovic EVO6 full system, a work of art in itself. Enjoy. I shot the video of this bike while just playing around on the dyno looking for a microscopic oil leak, turns out the generator cover gasket has a tiny tear in it, easy enough to fix. Big bore kits really work way better than they should on these engines, the Rotax built V990RR. The main reason is a large increase in port velocity on both the intake and exhaust side. For only a 6% change in displacement there are plenty of places in the rev range where 20% gains in horsepower and torque are accomplished!