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10 HP gone in a Year....

D

decoen

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Hi guys,

Last year i did this: http://www.998cc.org/forum/fz1-general-discussion/11899-dyno-d-very-happy.html

last week i thought i noticed less top speed, and decided to dyno again to check it out.
Now its down to (see attached images)
Same dyno, same driver, same mods, only thing done do it are: Oil change, spark plugs, syncronising of the trottle body, new tyres, new fuel line (not kinked).
2nd strange thing is that it look like the rev. limiter is kicking in earlyer then before. but only in 6th gear.

What do you guys think?
 
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Weather, humidity and mileage has a lot to do with HP output. I can feel a huge difference here in Florida between summer and winter riding. Especially when you barely brake the 80WHP mark... :(

Beast was saying something about different maps between cold and warm weather also... But 10HP seams like a lot...
 
Marthy said:
Weather, humidity and mileage has a lot to do with HP output. I can feel a huge difference here in Florida between summer and winter riding. Especially when you barely brake the 80WHP mark... :(

Beast was saying something about different maps between cold and warm weather also... But 10HP seams like a lot...
Click to expand...

I thought so too, thats why i did the dyno, to confirm it.
Because last year i could easily get to 260 kph or more.
Last week when i shifted from 5 to 6 @ 245 Kph it did not pull anymore, thats when i noticed. Tried it again and was the same.
Dyno from last year was at around the same date, weather was not a factor in this case said the tuner.
Temp and humi. was last year 31 c and 18 % now was 23.4 and 35 %.
I put on around 2000 Miles between dynos.
 
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What are your mods?

Are there strange sounds, smoking, terrible fuel economy etc? Are your brakes dragging? Critters in your exhaust system or Airbox? Secondary flies stuck in the closed position? If you have a PC, did you check the current map? Clutch slipping?

Overall, the curves look almost the same. Is it likely that your bike would be making an essentially consistent lower amount of power throughout the entire rev band? I don't really know for sure but it seems unlikely that some malfunction on the bike would give such consistent results but maybe. . . Suspect the dyno. Weather conditions, calibration, correction factors, wear and tear, operator etc etc.
 
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Could be many explanations .

Dyno calibration
Tight dry chain
Brake drag
Did you do at least 3 runs on the dyno ?
Barometric pressure different ? that can affect the reading more than humidity and temp
Dirty air filter
TPS ( throttle position sensor not giving 100% throttle )
clutch slip
Thicker oil / high oil level
Valve clearance tightening up

I could go on forever :D

Personally I would not worry about it and just ride it .
Maybe throw it back on the dyno next year and see if its lost anymore.


If anyone wants to cheat on the dyno here are a few tricks

Run the oil on the lowside
Use as light of an oil as your comfortable with... 0w20
push the brake pads away from the disc
Run the chain a touch loose and lube the hell out of it
 
I'm with Erban on this.
Those curves are so similar it appears that it is a dyno machine calibration thing. Not your bike. All test equipment drifts out of calibration over time and useage - and must be recalibrated. The dyno that you used, even though it is the same, is a piece of test equipment which is subject to calibration error. It will drift out of calibration - and must be periodically recalibrated.

Those curves of yours look identical - except for a calibration shift by the dyno. If there was something wrong with the output of the bike it would most likely show up as a drop in a certain area of RPM - or begin having a problem at a certain RPM - due to engine trouble - something breaking down - plugs, wires, etc. But there is not that in those curves. They are very much identical all the way through the RPM range - no troubles. Except they show a bias that builds steadily over the test range. the way a calibration shift of the equipment would show up.

Dustin is right. Forget it and ride....
 
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