Super Tigre 90 propeller advice
#1
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Super Tigre 90 propeller advice
I have a ST G90 on a SIG 4 Star 60. I've been using a 13X7, however, I would like to get a little more pull.
The recommended prop chart only goes up to a 13X7, however, I've been told a 14X6 will work well. I'm hesitant to use it since it is not on the chart and I don't want to damage the engine.
1. Will a 14X6 provide more pull?
2. Will it damage the engine?
The recommended prop chart only goes up to a 13X7, however, I've been told a 14X6 will work well. I'm hesitant to use it since it is not on the chart and I don't want to damage the engine.
1. Will a 14X6 provide more pull?
2. Will it damage the engine?
#3
My Feedback: (11)
RE: Super Tigre 90 propeller advice
A 14 x 6 is one prop that you can use, and it won't hurt the engine. It depends upon what you mean by "more pull". If you mean more static thrust, then the 14 x 6 will be OK. We usually, though, go for more RPM, and would investigate a 12 x 8 prop or so...turn the engine near 12,000 RPM and use whatever prop will turn that RPM and fly your model the way you like it. Too many people put too-large props on the G-90 and turn it too slowly. It runs very well in the high 11,000's and the carb works nicely when the engine's propped for that RPM.
#4
RE: Super Tigre 90 propeller advice
Bill
I have a .90 running on a Keekat. Its for speed in a pusher config. About all we can find is an APC 11x7 and a graupner 3 blade 12x8. Kind of in between. do you think the 11x7 will be ok??
My assumption is the3 blade 12x8 will be maybe a bit too much resulting in too low for rpm.
I wonder which one will be faster top end. We will also probably try the wood zinger 11x8. But cannot find a 2 blade 12x8 pusher or an APC 12x8 or 11x8. I am trying to get about 110mph. What is the true max rpm I can safely run?
any ideas on pusher props?
Also, looking for a tuned pipe recommendation, remembering its in a pusher config. I think if I had a touch more power, the 3 blade 12x8 graupner would spin up there.
First engine runs with the 3 blade is this weekend or early next week. apc 11x7 is on backorder.
I have heard there are guys turning the 11x7 at 15,000 rpm with the .75s thus my concern.
I have a .90 running on a Keekat. Its for speed in a pusher config. About all we can find is an APC 11x7 and a graupner 3 blade 12x8. Kind of in between. do you think the 11x7 will be ok??
My assumption is the3 blade 12x8 will be maybe a bit too much resulting in too low for rpm.
I wonder which one will be faster top end. We will also probably try the wood zinger 11x8. But cannot find a 2 blade 12x8 pusher or an APC 12x8 or 11x8. I am trying to get about 110mph. What is the true max rpm I can safely run?
any ideas on pusher props?
Also, looking for a tuned pipe recommendation, remembering its in a pusher config. I think if I had a touch more power, the 3 blade 12x8 graupner would spin up there.
First engine runs with the 3 blade is this weekend or early next week. apc 11x7 is on backorder.
I have heard there are guys turning the 11x7 at 15,000 rpm with the .75s thus my concern.
#5
My Feedback: (11)
RE: Super Tigre 90 propeller advice
We'd consider an 11 x 8 propeller or smaller too small. You'll get the engine to wind up, have a lousy idle and acceleration, and likely not last long at all.
For a pusher, your best bet is to get a prop that's slightly too large and start to cut it down until you get the performance you want..or close to it. Because pusher props are not made in very many sizes, that's the only way to get one that will work out.
With a pusher, you'd have to get a tuned pipe that had the exhaust outlet turn 180 degrees because you'd have to have the pipe pointing forward...remember, the prop would be in the way of mounting it so it went aft. That turn in the outlet tube would affect the pipe tuning, so you'd have to make one and 'try and see' for how it would work. There's no "off the shelf" answer here.
For a pusher, your best bet is to get a prop that's slightly too large and start to cut it down until you get the performance you want..or close to it. Because pusher props are not made in very many sizes, that's the only way to get one that will work out.
With a pusher, you'd have to get a tuned pipe that had the exhaust outlet turn 180 degrees because you'd have to have the pipe pointing forward...remember, the prop would be in the way of mounting it so it went aft. That turn in the outlet tube would affect the pipe tuning, so you'd have to make one and 'try and see' for how it would work. There's no "off the shelf" answer here.
#8
RE: Super Tigre 90 propeller advice
Im running a 15x4W on my .90 Fusion and it rocks but for the keecat, we cannot find a good pusher that has good thrust and speed both. so far the Graupner 11x8 is the best, but we are overreving the motor and prop to about 15,000 rpm, so we are being very careful. It has a Jett muffler and is pretty bad***** on the power range, but I want an 11x9 or 10 pusher which doesn't exist.
Even an 11x8 apc pusher would be good and more efficient.
Even an 11x8 apc pusher would be good and more efficient.
#9
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RE: Super Tigre 90 propeller advice
How about an 11 x 7? APC # LP1107P
Or a 10 x 8 pusher prop? APC # LP1008P
I think APC props are hard to beat. http://www.apcprop.com/
Or a 10 x 8 pusher prop? APC # LP1008P
I think APC props are hard to beat. http://www.apcprop.com/
#10
RE: Super Tigre 90 propeller advice
the 10x8 cannot make the required thrust, the 11x7 is just too flat for this motor. It does well on a tower 75, but its just too flat for this motor. It turned the graupner 14000 when it was on the stock muffler, which is really too fast for it. the 11x7 turned over 16k stock, which will destroy it in short order. what I need is an 11x9 apc.
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RE: Super Tigre 90 propeller advice
ORIGINAL: Bax
A 14 x 6 is one prop that you can use, and it won't hurt the engine. It depends upon what you mean by "more pull". If you mean more static thrust, then the 14 x 6 will be OK. We usually, though, go for more RPM, and would investigate a 12 x 8 prop or so...turn the engine near 12,000 RPM and use whatever prop will turn that RPM and fly your model the way you like it. Too many people put too-large props on the G-90 and turn it too slowly. It runs very well in the high 11,000's and the carb works nicely when the engine's propped for that RPM.
A 14 x 6 is one prop that you can use, and it won't hurt the engine. It depends upon what you mean by "more pull". If you mean more static thrust, then the 14 x 6 will be OK. We usually, though, go for more RPM, and would investigate a 12 x 8 prop or so...turn the engine near 12,000 RPM and use whatever prop will turn that RPM and fly your model the way you like it. Too many people put too-large props on the G-90 and turn it too slowly. It runs very well in the high 11,000's and the carb works nicely when the engine's propped for that RPM.
In the above post you say "Too many people put too-large props on the G-90 and turn it too slowly. It runs very well in the high 11,000's"
but in [link=http://www.rcuniverse.com/forum/fb.asp?m=4721011]this post[/link] you say "If you are turning the engine (G90) at 10,000 RPM, then you are turning it about as fast as is reasonable. We normally turn the engine just below 8,000 RPM.".
Can you advise which of these seemingly contradictory recommendations is correct?
#14
My Feedback: (11)
We'd consider that propeller size to be much too large for the G-90. You want to prop it so that it will turn in the high 11,000's. Anything much larger than a 14 x 6 will not allow that to happen. We really like a 12 x 8 or 13 x 6. They'll allow the engine to turn up and run very well with excellent handling.