Mine is a 98 VFR800 Hi, I am looking for mods or tunes that flesh out the 3000-6000 rpm range. Do slip ons that give more power help down low as well? What effect does a freer flilter have? I'd even sacrifice some top end for a bit more usable grunt. Cheers
Howdy, Check this out: 98 VFR 800 with K&N, full TwoBros and PCII Other than getting a big bore kit, there is not a lot you can do to seriously increase the engine's torque. The max torque is pretty much set in stone by the breathing characteristics of the engine and the size of the pistons. Turbos, Nitro and superchargers give more torque by seriously increasing cyclinder pressure, basically forced breathing. Adding a PCII makes the combustion more efficient. So for a fixed piston area, you will get a little more Torque and HP across the rev range. The air filter and exhaust pipe mods let the air flow freer so that it can move faster before going into the cyclinder, which will slightly raise the cylinder pressure over that of the stock system. If you really have to have low end torque, the VFR is probably not going to satisfy you. It is a high rev engine. The Triumph Sprint ST however, makes very good low end torque, same for the Aprillia Futura, Duc ST-2 or ST-4. They all have larger pistons than the VFR. Adios,
If you are looking for torque, try a Bandit 1200. My former bike would almost pull my arms off. Spencer
My other bike is a VTR1000 - for sale due to the purchase of the 800. I DONT EXPECT the same torque, but just feel the engine doesnt quite fuel crisply in the 3-6k zone and the bike feels, and sounds, flat in the higher gears. I know I need to use more revs than the VTR, and more gears but just want to make the most of the motor re breathing/tuning etc. I dont want to do anything major, just optimise I guess. My 1990 GPX seemed to pull better from 4000rpm, which is surprising. Thanks anyway.
Some, including Rumblefish on this forum, have gone to a smaller front sprocket (1tooth). Based on his comments, I'm seriously considering doing this as well. Seems like a pretty inexpensive and harmless mod to gain more bottom end... Ride safe ;D -Rick
At the expense of your gas mileage If you are a weekend strafer, go for it. If you like to tour, it will cost you. Adios,
I've been trying to get the most out of my engine setup as well. I dropped 1 tooth in the front sproket, and I like the results. The engine spins faster to the 4 valve mode, where the power is, and I don't have to slip the clutch as much in town. Unless you're doing 140mph on the highway, the lower gear won't make much a difference when cruising. My speedo is a bit optimistic now, though.
