Back to the dyno again!

[MPFab]

I recently installed a power comander on the "X" to see if I could eek out any more whp. Bike had made a best pull of 32.8whp with the airbox lid off a few weeks ago and I figured I see what I could do with a proper tune.
Loaded the base map from Dynojet for a stock bike with the airbox open and noted power was lower than previous by 1 whp. The dynojet base map was way rich and had a "humpy" fuel curve. We spent a couple hours sorting out the fueling and ended up with a very consistent and flat curve.
Along with fueling, I also tested an airbox mod found here:http://www.thumpertalk.com/forum/sho...d.php?t=663110
This showed significant gains throughout the power curve even before we had the fueling sorted.
After a couple hours of tuning we had appeared to have reached the limits of power with the current set up. We had been tuning with the baffle out and airbox lid still closed, although with (12) .75" holes drilled in it, hoping to reach 34whp. All we could get in that configuration was 33.78whp. We then opened the lid on the airbox to find that peak power was virtually identical, however, the open airbox did show pretty nice gains after 10K - Making 1-1.5whp more to the limiter.
As a last desperate attemp at eclipsing 34 whp we removed the K&N. This did the trick, although I would never ride, nor condone anyone riding around without it. It was simply a test.
Anyway here a few graphs.
1) Base run with PC and no tuning vs. Baffle removal only
2) Base run with PC and no tuning vs. Baffle out and final tune
3) Baffle out and final tune vs. Baffle out, lid open, and final tune
4)Baffle out, lid open, and final tune vs. No filter
5) Base run with PC and no tuning vs No fliter

[stom_m3]

Hey MPFab,

You should try lengthening the intake tract as this guy did,

http://www.thumpertalk.com/forum/sho...d.php?t=669265

Maybe you will be able to get over 34hp.

[MPFab]

Hey MPFab,

You should try lengthening the intake tract as this guy did,

http://www.thumpertalk.com/forum/sho...d.php?t=669265

Maybe you will be able to get over 34hp.

Thanks for the link! I'm working on something that should get well over 34

[maru]

A LONGER INTAKE TRACT WILL BRING THE POWER CURVE DOWN. It will make its power slightly sooner with slightly less peak.

[Rick_a]

A LONGER INTAKE TRACT WILL BRING THE POWER CURVE DOWN. It will make its power slightly sooner with slightly less peak.

Not necessarily. The optimum length varies by bike. It can be measured and calculated. The best lengths are often too long to be practical on most motorcycles. The idea is to tune to the reflective wave pulse that occurs when the intake valve closes so that it helps add momentum to the charge when the valve opens. Often the 2nd or 3rd is used where tuning for the strongest usually requires a super long intake tract.

[roadsterd]

Thanks for the link! I'm working on something that should get well over 34

Tell us more.

[Jaynen]

Ya no kidding tease

[pne]

hey man, sorry to bump such an old thread but did you find with the header/exhaust/ airbox lid open and the resistor on the intake sensor, were the AFR's good or too lean?