Super Tigre GS-45 & Jett Muffler
05-28-2009, 08:12 AM
#1
Thread Starter
Super Tigre GS-45 & Jett Muffler
I've got a new (32oz of fuel through it) GS-45 with the stock quiet muffler and Ritch's Brew 10% (11/11 blend) that I'm looking for a bit more performance from. It is currently turing an APC 11x6 (the prop I really want to use) right at 11,100 which seems a bit weak to me. I was expecting another 800-1000 out of it. Will I get that with one of the Jett-Stream Tuned Mufflers?
05-29-2009, 01:30 PM
#2
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RE: Super Tigre GS-45 & Jett Muffler
Thanks for writing......
Can you tell me a bit more about the aircraft you are flying with this engine? That can help a little with my answer.
Honestly, the 11x6 is too big for the ST 46 engine.Over-propped. Especially with a stock muffler. A 9x7, 10x6, 11x5 at most would be my recommendation.
In stock set up, you want to prop the engine to turn up closer to 14,000 rpm at peak.
Your fuel and run time so far are good. No issues there. But as you noted, the engine has been struggling. Even loaded down, it should get up over 12,000 with the 11x6.
You may want to put the engine on the test stand, put a 9x6 on it, and let it run for a few tanks. Find peak rpm, back off about 500 from there.... and just let it run. Should turn well above 14,000 with a 9x6 while still slightly rich. After that, you can try a 10x6 or your 11x6, and see if there was some improvement. Then perhaps some flight time with the lighter prop.
The Jett muffler works very well on theGS-45 engine. Expect to gain about 1000-1500 rpm over the stock muffler. But you have to set up and prop the engine to run in the correct rpm band. Prop for the jett-stream/ST combinationhas to be such that the engine turns "over"14,000 ground peak rpm. Typically the combination has no problem turning a 10x6 well above this number.
Usually the ST 40 and 46 engines with the jett-stream are set up for about 16,000 rpm at peak, and back off to around 15,200-15,400 for launch.
Can you tell me a bit more about the aircraft you are flying with this engine? That can help a little with my answer.
Honestly, the 11x6 is too big for the ST 46 engine.Over-propped. Especially with a stock muffler. A 9x7, 10x6, 11x5 at most would be my recommendation.
In stock set up, you want to prop the engine to turn up closer to 14,000 rpm at peak.
Your fuel and run time so far are good. No issues there. But as you noted, the engine has been struggling. Even loaded down, it should get up over 12,000 with the 11x6.
You may want to put the engine on the test stand, put a 9x6 on it, and let it run for a few tanks. Find peak rpm, back off about 500 from there.... and just let it run. Should turn well above 14,000 with a 9x6 while still slightly rich. After that, you can try a 10x6 or your 11x6, and see if there was some improvement. Then perhaps some flight time with the lighter prop.
The Jett muffler works very well on theGS-45 engine. Expect to gain about 1000-1500 rpm over the stock muffler. But you have to set up and prop the engine to run in the correct rpm band. Prop for the jett-stream/ST combinationhas to be such that the engine turns "over"14,000 ground peak rpm. Typically the combination has no problem turning a 10x6 well above this number.
Usually the ST 40 and 46 engines with the jett-stream are set up for about 16,000 rpm at peak, and back off to around 15,200-15,400 for launch.
05-29-2009, 03:09 PM
#3
Thread Starter
RE: Super Tigre GS-45 & Jett Muffler
The GS-45 is going into a Goldberg Tiger 2. If I can get close to 14,000 out of an APC 10x6 that will be more than enough for what I want to do. I just went to your site and ordered one. Thanks for the reply.
05-30-2009, 06:46 PM
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RE: Super Tigre GS-45 & Jett Muffler
Good deal....
The 10x6 is a good size prop in most cases anyway for the T2.
Once you have some time running the ST/Jett combination, you may want to try an 11x4 or 11x5. The plane is not ungodly fast, so the larger/flat prop will give you a bit better takeoff and landing performance.
Let me know how the project progresses.
Bob
The 10x6 is a good size prop in most cases anyway for the T2.
Once you have some time running the ST/Jett combination, you may want to try an 11x4 or 11x5. The plane is not ungodly fast, so the larger/flat prop will give you a bit better takeoff and landing performance.
Let me know how the project progresses.
Bob
