What RPM 582

[DieselFan]

I've got a 4:1 gearbox and a 582. At cruise one up @ 55mph rpm sits at 4000 (1000 prop rpm-very quiet), two up about 4300. The max she gets is 5900 rpm @ 90mph bar in, if I floor it (6000 MAX), she starts climbing at 90.

Now here's the predicament. Manual says max rpm on ground is 5500rpm. I pitched to that. The manual also says MAX Prop rpm is 1625 (x4 = 6500). But I can't seem to reach 6500? Should I reptich so that at 90mph I do 6400ish? This would push up my cruise etc. Remember it's a 4:1 gearbox so ample torque.

My take off runs seem on par with other trikes 1 and 2 up but Max rpm on takeoff is 5800ish.

Also I've got the fuel consumption graph from the Rotax manual but I think I'm misinterpreting it. What should best cruise rpm be?

Looking at the Dyno graph, I'm running the motor under it's power band?

Cruise control @ 4000 rpm is about 1/3.

Thanks

[Big-D]

Ask something easier

D

[Dreamer]

I would say it should go fast enough to take off and stay up but not so fast that it takes off without the rest of the plane my $2 Zim worth of technical expertise.

[Tumbleweed]

--------------------------------------------------------------------------------



Ask something easier
[/quote]


DF You gonna have to find clever mates, you seem to have hit 'clown hour'

[DieselFan]

Ask something easier

D

Must I
a) Rob a bank to support this hobby
b) Rob a cash in transit vehicle?
c) Stand on corner Grayston and Rivonia walking with a limp and my crutches

Cool 500 posts

[John Young]

Howdy DieselFan,

Static thrust through to max. take-off 6 200 rpm.

Solo cruise "hands-off" 52-54 mph 5 200 to 5 300 rpm.

Dual cruise 5 700 rpm.

“Lekker” decent (+500’) 4 000 rpm.

“Lekker” climb (+500’ solo) 5 900 rpm - Dual (+500') 6 100.

Bear in mind that we fly at < 3 000' AMSL and extreme DA condx excluded.

Regards
John ZU-CIB

[Big-D]

Must I
a) Rob a bank to support this hobby
b) Rob a cash in transit vehicle?
c) Stand on corner Grayston and Rivonia walking with a limp and my crutches

Cool 500 posts

Congrats on 500 posts dude, sorry to keep you waiting for the airlaw book :D Found it eventually didn't I
Bet you were scared being left all alone with P2? :D


D

[Pumba]

DF

I had a similar set up. Aerotrike Safari, 582, E-box with 4:1 ratio. Bought the aerie with 6 blade Ivo prop. I never really flew this prop, and replaced it with a 3 blade 72" NC prop. I can't remember the exact pitch, but it was around 25 to 27 degrees. Static run-up gave me 6,400 rpm, and would see 6,800 on climb out. Cruise, one up around 5,000 rpm, and 5,400 two up at Highveld altitude.

From what you are describing, you are not running your 582 anywhere near optimum, and most likely it is due to the prop pitched to course.

Reduce a degree at a time until you see around 6,400 on static run up. Don't make the mistake of thinking that you are saving fuel or running better at low revs. Two strokes are designed to perform at their peak at high rpm. Rotax specifies 6,800 for max 3 minutes and 6,500 max continuous on this engine if memory serves me right.

Best
Barry

[DieselFan]

Thanks for all the advice! Big D, I was a tad concerned about P2 esp when you can't see P2's eyes behind that hair

With the plane -

Will reduce pitch a tad, I just don't want to over rev as the wing has quite a large speed range 37mph stall and easy to do 90mph - 50 mph range.

Currently once I start taxying I just let it idle as there's already thrust to keep it taxying and thats at 1500rpm.

It's a 4 blade Arplast prop.

I read of some guys with Challengers and S12's with 582's who cruise two up at 4800

My experimenting now starts