Yamma-Fox

Contributing Member
  • Content count

    616
  • Joined

  • Last visited


Community Reputation

315 Excellent

1 Follower



About Yamma-Fox

  • Rank
    Advanced Member
  • Birthday 08/23/1973

Profile Information

  • Gender Male
  • Location Nevis, MN

Recent Profile Visitors


2,715 profile views

Yamma-Fox's Activity

  1. Yamma-Fox added a post in a topic Ski Day   

    I've been itching to get mine out of the snowbank(ed in hangar) too.  These pics will help get me motivated!
    • 0
  2. Yamma-Fox added a post in a topic Yamaha Engine Mounts and FWF components for Avid!   

    William's phone number is 701-651-0122 for anyone interested in his mount or other FWF parts for the Yamaha.
    • 0
  3. Yamma-Fox added a post in a topic Length of prop blades verses diameter of prop (warp drive)   

    I thought their website spelled out the details on that?  But maybe I'm thinking of another prop mfg's website...
    • 0
  4. Yamma-Fox added a post in a topic Kitfox 2 $8500 on barnstormers   

    Jim you need to start snapping these up..  flip em and make a few bucks.
    Then start another reality TV show where you are the star and get rich!
    Call it:   "Flip This Plane"

     
    • 0
  5. Yamma-Fox added a post in a topic Horsepower/Torque   

    I'd say you are spot on.  
    Many people don't understand that dyno charts ARE at full throttle for all data points.  You open it up and let the dyno load it down to different rpms and take torque readings. Then HP is figured backwards through the formula (T x RPM) / 5232 and the curve between the points that the dyno recorded is interpolated.
    Common misunderstanding is for someone to think that if they throttle back to 5200rpm (in your example) that they are getting the  50 HP from the chart but the engine is actually putting out far less when throttled back.  
    • 0
  6. Yamma-Fox added a post in a topic Horsepower/Torque   

    I guess I look at HP as king in determining an engines "power" because it is the combined product of torque and rpm.  It gives a better sense of what work the motor can do.
    As mentioned above the awesome total (horse)power of a PT6 is all about rpm and very little about torque.  And a steam engine's awesome (horse)power is all about torque and very little about rpm.  IMO you really need to rate each by HP to be fair to one another.
    So anyway thats why I think HP is a better "guage" of total power but next to as important is the "power band" which in my mind is best defined by torque graphed against rpm.  A long flat torque curve = a broad powerband.
    Two charts below show this.  The Yamaha Apex is an example of a broad powerband, with torque (value read off vertical scale on right) remaining very constant from 6500 to 10,500 rpm.  A 4 thousand rpm power band where consant torque gives HP the opportunity to build from about 95 to 150 (read off vertical scale on left)
    The second graph is of a 2 stroke 2cyl liquid Rotax 440.  Two strokes generally build great torque but hold it for a shorter rpm range.  The "rpm length" of that flat area of torque occurs over a shorter range (2 thousand rpm or so).  "Peaky" or "Narrow Power Band" where it is even more important to get your snowmo clutching or prop size and pitch just right to harness the power. 
    So IMO HP is the best total power rating and torque curve is the best way to understand how the engine makes that power... and how fussy it might be if "optimal" canditions are not met.
     


    • 0
  7. Yamma-Fox added a post in a topic Horsepower/Torque   

    I'll give it a shot here:  First off you cant have one without the other since they are tied to each other but in my simple (and sometimes warped) way of thinking - It's either additional torque or additional rpm that "makes" additional HP.  One (or both) has to "be the multpilier" in the equation.
    I think of torque as a big guy slowly (low rpm) powering someone over when armwrestling.  Torque makes the power... more torque wins.
    Each engine is obviously different but typically when an engine begins to level off at peak torque then additional rpm can increase HP, even though torque is not changing much with more rpm.  You can see that in dyno charts and in the general equation:
    HP= (Torque x RPM) /5252
    I think of extra rpm making HP as beating a stronger guy (guy with more torque than you) in armwrestling by gaining speed and using that speed to beat him.  With the extra speed you may have less torque than him but you have more resultant HP (due to inertia/momentum).  Speed (rpm) makes more power and more speed wins.
    Side notes:
    The rpm side of the equation is where the little 1000cc 4cyl Yamaha gets its power (rpm makes HP).  It would be a pretty modest powerplant if it's rpm were more "normal".  
    Boost (turbo) gives an engine more torque at a given rpm, and therefore more HP (torque makes HP). 
    Also, most importantly our PSRUs primarily bring prop rpm in range, but also are torque converters...  trading RPM for a huge increase in torque.  So when measured at the prop, torque always is the bigger multiplier (over rpm) in the power equation for what we are doing, and I think that is why most people will say that "torque turns the prop".
     
    • 3
  8. Yamma-Fox added a post in a topic Strut Farings   

    To give you an idea of how they look unpainted and "slapped on" - here's a couple kinda crappy pics of my KF5 with the snap on plastic fairings kitfox sells.


    • 1
  9. Yamma-Fox added a post in a topic Strut Farings   

    Looks like you made up your mind but the kitfox kit is a 1 hour job.  If "looks" are paramount then build your own but with the kitfox ones you just trim, snap on and fly.  
    The kit comes with an aluminum cuff for the lower union of the two struts but I didn't see a reason to mess with it.  If I ordered again I'd just buy the 4 snap fit plastic fairings.
    • 0
  10. Yamma-Fox added a post in a topic Making engine mount for phaser   

    Sometime here you need to get some stick time behind one Jim!  Mine only rapps out about 9k so that will be a good 1st step initiation
    FWIW the Phazer ecu rev limiter is up around 12k and many sport bikes (of the same engine class) are up N of 15k.  They're made to do it! 
    • 1
  11. Yamma-Fox added a post in a topic Making engine mount for phaser   

     
    Teal is hoping to have a prototype gearbox out this spring for testing.  It will be a design similar to his Skytrax Apex gearbox-adapter  (all in one) that replaces the end housing on the engine.
    Otherwise "72chevy" here in this group has everyone beat with his prototype running a c box and pulling how much thrust at what weight again Duke?
    • 0
  12. Yamma-Fox added a post in a topic Rivets on flaperon horn   

    Yep my kitfox 5 has em just like that.  Shown in the builders manual.  They are sst pop rivets and with a little time they get a little slack.  I just replaced all mine at 500hrs TT.  Same used on my rudder pedal torque tubes.  Those had a bit more slop in them.
    • 0
  13. Yamma-Fox added a post in a topic Just purchased a Kitfox IV   

    And were you able to purchase the apex mount, header, and R1 airbox that those brothers built for that plane?
    • 0
  14. Yamma-Fox added a post in a topic Just purchased a Kitfox IV   

    Welcome back sir!  Congratulations on the new airplane,  and with regard to the Yamaha, welcome to the dark side!
     
     

    • 1
  15. Yamma-Fox added a post in a topic Converting to nosegear   

    There's always a dumbass or two out there who will make stupid comments.  You'll find less of em here because we'll all hop on and tally-whack them but Facebook is often like a a steamy shit pile that attracts those type of flys
    (Spoken from first hand experience LOL)
    As far as your mod to trike - I really like it and would probably do something very similar if I ever go back to wheels.  I would like to have a trike that has a super light nose (mains set up very slightly aft of CG) and keep the tailwheel... kind of a hybrid where you can power down the tail at will while taxiing,  or plant it on the nose depending on your elevator input.
    Keep us up to date on how the project is going!
    • 0