Dyno talk
http://www.rc51.org/dynotuning.htmWorth a read to help interpret the results and alternate tunings.
"The majority of tuning all comes down to the Air Fuel ratio. Optimum power is generally around 12.6:1 while the stoichiometric value for a gasoline burning engine is about 14.6:1 for a good compromise of performance & mileage while Dynojet themselves generally target 13.2:1 when they build their own maps."
"Exhaust dynamics is a tricky business, but if the flow is improved & the reversion waves are tuned properly then more fuel can be added & the more fuel you have the more power you get. If you have to remove fuel due to a poor flow design or the reversion waves are kicking back to the cylinder & meeting the next exhaust pulse at any point in the rev range then you simply are not going to get good power gains at that point."
If we could find pipes that would ideally scavenge the exhaust flow by introducing a low pressure zone along the way, or at the least, would not offer pressure backlash against the exhaust cycles, it's all downhill from there to maximize HP or find your desired balance of HP vs. torque via jets & needles et al. I'm not clear which pipes those are, or if they even exist for our bikes. At $300 to $700 a pop for aftermarket pipes, I'm not going to the trial and error method to find them. Got mouths to feed.
To the dismay of many seeking HP above all, I'm going to de-tune mine a little further and bring the MPGs back up to 50 MPG. At my current 13.2:1 offering 40 MPG, I apparently have plenty of head room to cut the fuel back a bit and still not exceed the magic threshold of 14.6:1 (or 14.7:1, depending upon which method you desire.) What can I tell ya - I'm an old fart with a tight wallet.
Footnote: RJS runs a Dynojet brand unit, with the Dynojet software mapping.
