StephenUK

Anyone know what prop I should be using for a Super Tigre 90 on a Genesis tuned pipe? The engine is fitted in a Dave Smith Models Excelsior 177?

I know a few people have used this set up in Uk pattern contests.

Dan.P

Try a apc 14:10 thats what im running on mine.

jonlowe

My Feedback: (12)

Dan,
What is your overall setup, carb, pipe, pipe length, header, etc.? Are you running any sort of pump? What nitro in your fuel, if any? What RPMs are you getting?

I am also trying a 14x10, but am having some engine issues, and I wondered what you had found successful.

Thanks.

Jon Lowe

Neo02

I used a 15x8 APC on my earlier pattern floatplane, quieter and smooother than a 14x10 but my motor was performing real well and I'm not sure every ST90 runs with this prop. Worth give it a try, though.

Regards,
-Fabrizio

EL TEMUCANO

On my epsilon , i used an S. T. G90 with an APC 14/8 , 9.500 RPM
ilimited vertical
A good medium setup and an exelent ralenty.

Sergio

Dan.P

I am running a completly stock setup and no pump. I don´t really know the rpms. My fuel is 15% oil and 10% nitro. The engine runs great and is very qiet on the 14:10. What issues are you having with yours?

Dan.

Schpankme

StephenUK,

Ok, so you’ve got youself a Dave Smith Models, “Excelsior 177”, with an ST G90 powerplant and an Genesis (510mm) tuned pipe. That’s a beautiful combo if built light.

Since were flying pattern, our goal is to provide for a constant speed (pace) throughout the up & dwn vertical lines and in level flight. Here’s my recommendation to match the right Prop with your airframe and power plant choice.

- Super Tiger G-90
- Genesis pipe @ 510mm
- 5% Nitro

- APC 16x6 Prop
- Max Torque 231 @ 7,800 RPM

- APC 16x8 Prop
- Torque 210 @ 7200 RPM

_________
Schpankme

jonlowe

My Feedback: (12)

I had it eat a ring. Wasn't sure if I was trying to turn it too slow, or if I had other issues. From what I see here, everyone is turning them pretty slow.

Would still like to know what length to the baffle you are running on your pipe. By that I mean, measure from the plug, around the header, to the first baffle in the pipe.

Thanks.

Jon Lowe

Thanks!

wildthing7037

Hi Everyone,

I too have a Super Tigre 90 in a pattern model, and just reading through these prop sizes, they all seems quite big. Mine has an APC 13x6 bolted on it at the moment, and I am begining to wonder if this prop is a little on the small size. The model is fairly big, and probably s little heavy, but seems to go alright. Should I switch to a 13x8 or mabye a 14x6? Will this help performance?
I have been running 10% nitro, and stock muffler and plug.

Thanks,

Stefan

HCRCflyer

My Feedback: (1)

I/m running a ST .90 (older model) muffler pressure ST quiet muffler in a blackhorse Bravo 303 Pattern version.
I am using a 13-8 APC turning about 11K flys the plane well. with a tuned pipe I imagine I could go to the props listed above.
I tried a 13-9(10K) the motor turned it fine but the plane was lacking in verticals. I imagine a 14-6 14-7 would be about right.
(gear is a little short for the 14 and a grass field. I am running 15% nitro with 18% oil and OS-F plug out of habit.
Just a few more data points. (Oh yea I am a little above sealevel)

StephenUK

thank you all!

seems that a wide slection of props are ok!

Schpankme, I'm gonna try the 16x8 first if I can get the ground clearence with this model

stephen

EL TEMUCANO

Stephen UK

If you put 16/8, I think you don´t read anything....
sorry for the sincerity.

[sm=confused.gif][sm=bananahead.gif][sm=confused.gif]

Sergio

Schpankme

Stephen,

Please use the 16x6 prop as shown in bold above, the other prop was there as reference only to establish that it's Torque that turns your prop, not HP.

Note - the Super Tiger G90 makes it's Maximum Torque @ 7800 RPMs.

If prop clearance is going to be a problem (you got retracts), you'll of course want to use a smaller diameter prop and increase pitch, 15x8. You can even get creative and try the 15.25x7.25 or 14.5x6x3-blade, these props will provide the same static thrust loads and RPM range to that of the 16x6. And of course let me point out to those that will remind us, your RPM will increase at flying speed as the prop unloads, so static thrust is only a starting point for optimum prop selection.

Remember, our goal is 7800 to 8000 RPMs, as you increase prop pitch (6 to 8 to 10) you also increase plane speed, and the same can be said for reducing prop diam. Here's your estimated speed chart: 16x6 = 44MPH, 15.25x7.25 = 54MPH, 15x8 = 59MPH

There are additional benifits to be gained by using the 16x6 prop, the noise level and your fuel consumption will be lower and the engine will run cooler compared to using a smaller prop.

- ST G-90
- Genesis pipe @ 510mm
- 5% Nitro

- APC 16x6 Prop
- Max Torque 231 @ 7,800 RPM

_________
Schpankme