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More Turbo-Jett Questions


Old 06-19-2008, 08:38 AM
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Default More Turbo-Jett Questions

I Got my Turbo-Jett for 120AX in the mail today.

Firstly, the port on the muffler is roughly only about 50% the area of the exhaust port on the engine. I'm sure there's a reason for this. Can you tell me why?

My next question is about the size.
Looking at the size chart on the web i was expecting a muffler 3.25" diameter and 2" deep.
Instead my muffler is 3.5" diameter by 1.6" deep which appears to be a squat 30cc size.
Again, i'm sure Dubb has probably improved the design and changed the specs and it's not issue, but a curious mind wants to know.

On the size thing again. You said in another of my threads that the OS .91 uses the same size 20cc muffler. Is that still the case. I ordered a 42mm adapter plate so i could also use this muffler for .91 size engines but i feel the muffler may be to big for the engine.


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Old 06-19-2008, 10:00 AM
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Default RE: More Turbo-Jett Questions

Dub did make a few size changes - helped with with internal flow and internal volume.

I will double check on the current dimensions so I can get the web page up to date. My bad there.

Yes, the OS91 uses the 20cc muffler. It can use the 10cc, but we find that the 20cc works better for most installations. We use the 20cc on the Jett 90L and 100L engines.

The entry port into the muffler usually appears smaller than the engine exhaust. Crankcases on most sport engines usually have over-sized exhaust outlets (thin wall) to help save weight. If you look at racing engines, the crankcase ports are actually small compared to what you might see on a sport .46 engine.

I believe Dub has the OS120 mounting plate sized for the best performance balance.

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