Funny you should mention this ... As I live about an hour away from Concord, NH, I took advantage of this past weekends AMA races at NHIS, as well as the presence of Marc S. at said races to make a revised fuel map EPROM for my 00.5 Mille. My plan was to ride up to NHIS on Wednesday night and spend Thursday with Marc, tinkering with the EPROM and dyno as time and Marc's workload permitted. I should note that I bought the bike in late February and that it has some 1300 miles on it. The first service was recently done and the bike came derestricted from the dealer (South Shore in Quincy MA -- good guys!) We started by doing a baseline measurement of the bike, with stock exhaust on the dyno. My friend Patrick, who works for Marc at some of the races, operated the dyno. He was fairly impressed with how well the stock map performed. The torque curve was quite flat, rising to 54 Ft/Lbs at 5000 rpm and staying there until 10,000rpm, where it dropped back to 47.6. Peak HP was 90.5 at 10k rpm. The CO and HClines were also quite flat, but indicated that the map was running the engine slightly lean across the range, with a bit of a dip at 5k [Isn't that were the EPA tests emissions ...?] (I'd scan in the printout, but it got shoved into various pockets, crumpled, extracted with oily hands and otherwise mistreated ...) Marc had, on hand, a replacement EPROM with a map he'd built. With some trepidation, I extracted the CPU from the bike and slit the "Warning -- Removing this label will make your warranty NULL AND VOID" tape across the halves of the CPU box. Swapping the chip was a simple matter of pulling up the silicone sealer drizzled across the PROM and prying it up. Aprilia cleverly mounted the fuel map EPROM on a socket to make this easy (unlike Audi, which solders the PROM to the circuit board :{). Good Aprilia! We dyno'ed the new EPROM. I have managed to misplace the printout from this run, but horsepower and torque were both up about 2 across the board, with peak horsepower coming in the same RPM. (N.B. The Aprilia speedo was in complete agreement with the EC997 dyno until about 115 MPH, where it started reading 5 mph low.) At this point I was pretty happy and planned to go back to the garage which Team Daemon Racing rents (We're a LRRS team, fielding a number of bikes in club races. Two of our riders were running in the AMA races -- one in 600/750 Supersport and the other in Pro Thunder) and install the spiffy Akrapovic exhaust I had waiting. Mr. Salvisberg had other plans for me ... Marc reviewed the data from the second dyno run and pulled out a PROMP berner and a stick of fresh PROMs ... For the rest of the afternoon he was handing me chips. I would unplug the CPU, unscrew the four screws holding the two halves of the box together and swap the EPROM. Then he sent me out onto Rt 106 to try the bike at various speeds and throttle openings. Each time I returned searching questions were asked: How did it feel? What do you mean by "it's surging" ...? Did you like it? Was there anything you didn't like? Because there were two fuel maps in each EPROM, we eventually soldered in a simple SPST on/off switch so that I could toggle back and forth between the maps. I even got smart enough to duct tape the switch somewhere accessible ... (Unscrewing the seat every 20 minutes to swap things got really old, really fast ...) By the end of the afternoon we ended up with a //brilliant// map. It was completely driveable from 2500 RPM right thru to redline at any throttle opening. Seat of the pants analysis feels like the torque curve is completely smooth, buth no "bumbs" (what I was calling "surge" and Marc was translating as "No, not surge, surge is a lean condition, you mean ``on the pipe'' or ``pulling harder''). In addition to that #1 map, there is a second, more aggressive map which Marc says he richened significantly above 6k rpm. My bum agrees that the bike pulls harder with this map, but it doesn't quite have the smoothness of map #1 Interestingly, at one stage we had two maps with identical fueling parameters in the range 2k - 4k, yet the second, more extreme, map with more richening up top didn't run as well in the low RPM range. Marc and I were theorizing about interpolation activity in the CPU, but I digress. I never did have a chance to redyno the bike with the latest chip and the Akra slip on. I think I gained perhaps another HP or two for a peak of about 95. WHo cares; I'm delighted with how much better the bike behaves across the board. I was less interested in making max HP/TOrque as I'm not racing the bike. I have a few shots of the Akrapovic sitting at: http://www.tifosi.com/rali/Gallery/RSVMille/akra I neglected to bring the camera to the Factory setup at NHIS, so I don't have pictures of the inside of the CPU box. I'll add some, as well as pictures of the chip (Woohoo, it's a rectanglular centipede with metal legs ...) I want to thank Marc for his patience -- particularly with my novice effort at being a test rider and halting efforts at describing what I was feeling -- and willingness to spend time he could have been (should have been?) devoting to the folks racing that weekend playing with my Mille instead. Both Salome and I are grateful! EPROM. My vote is definitely EPROM Reto L. -- rali@tifosi.com