klrtovfr Posted May 9, 2016 Share Posted May 9, 2016 We had a bike night at the local cycle gear and they brought in a dyno. I didn't need to see the results because 1. they arnt completely accurate and 2. I already knew the ballpark it would be in but I just wanted to hear it while not riding it down the racetrack. It is fairly loud but it may be a little exaggerated and was quieter than the crossplane r1 with an a shorty. 2002 VFR800 Gutted Stock Exhaust with slightly enlarged exit holes 1999 OEM VFR Catless Header pair valve and snorkel removed BMC Air Filter Power Commander 5 untuned(unsure of the map) -1/+2 gearing https://youtu.be/V48r8V6t2KM Link to comment Share on other sites More sharing options...
Skimball Posted May 11, 2016 Share Posted May 11, 2016 Looks very similar to mine from 2009. Power Commander, Staintunes, pair valve and snorkel removal, K&N filter. Link to comment Share on other sites More sharing options...
Member Contributer Dutchy Posted May 11, 2016 Member Contributer Share Posted May 11, 2016 4th Gen with Akrapovic+db-killer, no re-jetting simple run during an open day and from a German magazine years ago: Link to comment Share on other sites More sharing options...
Morph3us Posted May 11, 2016 Share Posted May 11, 2016 The 4th gen 750 is damn impressive. Looks like the pick of the bunch Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Member Contributer Dutchy Posted May 11, 2016 Member Contributer Share Posted May 11, 2016 The 750 in the graph is -what the Murricans call- a 3rd Gen, we know it as the RC36-1 :-) Fwiw, the German text stated that, judging by the numbers alone, the1990 appears the most powerfull, attributed to the fact that in those years, noise and pollution laws were less stringent (in the EU/Germany) Link to comment Share on other sites More sharing options...
Storx Posted May 11, 2016 Share Posted May 11, 2016 how do you like the gearing change OP, I just got my viffer and feel like the gearing in the bike is way way to long... the bike does not like being under 3k rpms and trying to use 6th around my town riding is damn near impossible without it shuddering at me when I got to accelerate some... Also is the stock oem 99 header worth it over like the $300 aftermarket catless headers? been contemplating getting a set since my exhaust system is pretty rusty leading up to the two brothers mufflers... Link to comment Share on other sites More sharing options...
klrtovfr Posted May 14, 2016 Author Share Posted May 14, 2016 On 5/11/2016 at 2:51 PM, Storx said: how do you like the gearing change OP, I just got my viffer and feel like the gearing in the bike is way way to long... the bike does not like being under 3k rpms and trying to use 6th around my town riding is damn near impossible without it shuddering at me when I got to accelerate some... Also is the stock oem 99 header worth it over like the $300 aftermarket catless headers? been contemplating getting a set since my exhaust system is pretty rusty leading up to the two brothers mufflers... I did it for the track since the engine doesn't have enough power to reach top speed at redline in 6th on a nearly 1 mile straight and Its more beneficial to get the quicker drive out of the corners. On the street with that combination basically it feels more responsive in the twisties and its still ok for interstates however its basically like only having 5 gears of oem gearing. The 99 headers are mild steel vs the stainless steel aftermarkets. the 99 headers rust. Mine had surface rust to begin with and I sanded as much as I could off it and painted it with some 2000 degree paint. about 2 years in and the rust is starting to come back through. You can try having it ceramic coated but Ive heard of that failing after awhile too. Ive read that wiping the pipes periodically with engine oil keeps it from rusting as well. Its a cost vs hassle choice. Link to comment Share on other sites More sharing options...
dfh Posted May 17, 2016 Share Posted May 17, 2016 On 11 May 2016 at 5:21 AM, Storx said: how do you like the gearing change OP, I just got my viffer and feel like the gearing in the bike is way way to long... the bike does not like being under 3k rpms and trying to use 6th around my town riding is damn near impossible without it shuddering at me when I got to accelerate some... Also is the stock oem 99 header worth it over like the $300 aftermarket catless headers? been contemplating getting a set since my exhaust system is pretty rusty leading up to the two brothers mufflers... So don't ride around town in 6th, there are five other gears to choose from after all. Why on earth would you ride a VFR by choice under 3000 rpm? VFR750's & VFR800's produce maximum Brake Mean Effective Pressure or bemp at or around 8000rpm. That is why peak torque appears around this point. On partial throttle openings fuel efficiency is also maximised at this point. Don't want to cruise around at 8000rpm? Look at the graphs above from Klrtovfr. At 3000rpm his 6g makes 45ft-lbs of torque but less than 30hp with the throttle wide open. At 5500rpm his 6g makes the same torque figure but produces 55hp with the throttle wide open. What does this mean in the real world? If 20 to 30 hp is all you need to maintain town speeds then cruising around at 5500 rpm means you can throttle back to half throttle, pick up smoothness, increase fuel efficiency & have headroom to spare to accelerate just by opening the throttle. Is 5500rpm a too high a rpm for cruising. On the VFR its 50% of peak power revs & less than 45% of maximum revs. So no need to change the gearing, just change the gear you cruise in. If 5500rpm at your towns urban speed limit necessitates 3rd gear, then use that. Cheaper than a sprocket change and when you actually leave town you will have more useful ratios to use on the open road. Link to comment Share on other sites More sharing options...
Knight Posted May 17, 2016 Share Posted May 17, 2016 On 5/11/2016 at 3:51 PM, Storx said: how do you like the gearing change OP, I just got my viffer and feel like the gearing in the bike is way way to long... the bike does not like being under 3k rpms and trying to use 6th around my town riding is damn near impossible without it shuddering at me when I got to accelerate some... Realize that -1/+2 is extremely aggressive gearing. That must be a wheelie machine, yes? I have -1 up front and do a lot of city riding at 25-45 mph, and connecting the neighborhoods via the freeway. I do not do any high speed riding. This works just about perfectly for me. Occasionally I think the gearing is a touch too short and miss the ability to stay in first gear a bit longer in between stoplights. Here I have read that the +2 in back would be slightly less aggressive than a -1 up front. If so I would recommend that setup as well if your habits are similar to mine. Regarding sixth gear: Even at -1 up front I do not use sixth much unless the traffic is moving in a straight line at a constant at 70 mph+. For any curvy freeway or traffic that requires periodic maneuvering, sixth gear is too weak. Fight the natural tendency to upshift just because the gear is available. Also, never allow the engine to shudder. Use the gears to keep the RPM "slightly high" any time you are accelerating. Only by practice and feeling the feedback do we learn what "slightly high" is for each bike. Lugging the engine cumulatively breaks down the crank and bearings. With stock gearing sixth gear is a compromise that allows you to go 130 mph+ but at freeway speeds is good only for the lightest throttle cruising under ideal conditions. Link to comment Share on other sites More sharing options...
Member Contributer Mohawk Posted May 17, 2016 Member Contributer Share Posted May 17, 2016 Sorry had to, now has 300rpm more so 120hp :) Link to comment Share on other sites More sharing options...
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