|
My CBR will maintain a constant speed down to 3k. If you try to accelerate slightly you need to be at 3.5k and higher rates of acceleration need to begin no lower than 4k RPM.
Lugging is a combination of two things, but with fuel injection it is primarily due to RPM being so low that you can feel each power pulse and the oscillations in pressure that occurred when the harmonics of air flow are insufficient to keep a fairly consistent pressure into the cylinder.
In the old days lugging was aggravated by the issue of the volume of fuel that was added to the normal flow by the accelerator pump. When you pushed the gas pedal at to low a speed the fuel delivery was far too much for proper atomization and combustion. The inconsistent mixture was a recipe for pre ignition with high percentages of the fuel delivered not being atomized and burned properly.
Most of the bikes I have been on in recent years will basically "tell" you when they are happy with the RPM and load conditions they are experiencing. The Vulcan really starts to smooth out at 50 MPH in 6th gear. I think the CBR is close to that same RPM when it really starts to produce a smooth flow of power. My guess would be in the CBR your best P&G range would be from 4-6k RPM with manifold vacuum at 80% of atmospheric or higher if it does not have full load enrichment.
regards
Mech
|