Quote:
Originally Posted by punishum808
That is NOT what I asked. It was about CR carbs and the jetting that comes from the factory. I was seeking baselines for jetting the CRs.
As for dirty carbs I have turned the clicky thingy a few times so I do have very little experience with vehicles. But here are a few of the present projects to which I have built myself.
Wow, you sound really knowledgeable, what is VE?
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Sorry I got mixed up about factory vs. your CR carbs. Best to use wideband and datalog actual AFR. Then go from there. You can do it by feel, but it takes a lot longer and you end up leaving lots of power on table. With wideband, dyno and programmable EFI, I can extract max-power out of engine in about 5-10 dyno pulls, 30-45 minutes. Last 3-4 runs typically eeks out just +1-2% more.
VE = volumetric-efficiency. It's where intake & exhaust tract size, length and shape along with valve-size, lift and timing all coincides for maximum-flow. Due to helmholz-resonance of engine and timing of pressure-waves bouncing back and forth, engine has maximum efficiency in getting most air into cylinders only in certain range of RPMs. Above and below this, it takes in less air per intake-stroke.
When max-VE occurs, cylinders suck in most air per intake-stroke and generates maximum BMEP - Brake Mean Effective Pressure in cylinder. This generates most PSI pushing down on piston and gives most torque. On Ninjette, this occurs around 8-9k RPM (see dyno chart below).
Factory bike slows down acceleration after torque-peak. On race engines, you want to tune to move this torque-peak into higher-RPMs. Calculated max-HP is then also increased which really helps trap-speeds. Main benefit is allowing bike to stay in lower-gears all way to redline for maximum thrust at contact patch.
Nice ride! and awesome photo!!!
