Power output versus throttle opening

Craig380 · Post by **Craig380** » Sun Mar 29, 2009 5:37 am

In the latest issue of Performance Bikes there's an interesting dyno test on a new R6 Yam.

They did two runs: one run at 100% throttle opening, and one at 50% throttle opening. The figures were:

Full throttle: 109bhp at 14,500rpm

Half throttle: 101.5bhp at 14,500rpm

Torque figures were comparable too -- at half throttle, the bike was putting out over 90% of the torque at full throttle.

I thought it was kinda interesting that half throttle was giving so much power.

Coyote · Post by **Coyote** » Sun Mar 29, 2009 7:24 am

I'm confused. This thing red lines at half throttle

H2RICK · Post by **H2RICK** » Sun Mar 29, 2009 3:48 pm

I believe they'd be doing the runs in different gears to get their figures, Coyote.

rngdng · Post by **rngdng** » Mon Mar 30, 2009 7:53 am

That makes sense to me. Power requirements aren't linear. To increase from 101-109 HP, it takes more throttle than it would take to increase from 98-101.

On the Frigate I rode in the Navy, we had two gas turbine engines for propulsion; one engine would get us about 30 kts, but TWO engines would get us about 33 kts, at twice the fuel consumption. It's the same sort of thing.

Lane

tz375 · Post by **tz375** » Mon Mar 30, 2009 8:36 am

An interesting twist is that we rarely open the throttle against the stop. Most of us open it to half or maybe 3/4. We increase main jet size for WOT and rarely change jetting for the place we ride most often - mid range.

That's one reason why most of us seize our hot rods at half throttle and can't work out what went wrong.

H2RICK · Post by **H2RICK** » Mon Mar 30, 2009 9:34 pm

As I posted previously, words from a guy much wiser than me advised to jet from the main jet backwards. Then it's very hard to do any accidental damage.