Modifying your Evolution 26 GT Tuned Muffler

HIGH Performance Modification

In order to take full advantage of your EVOLUTION 26 GT engine's available horsepower you have to get creative. The optional tuned pipe works much better than all the other mufflers, BUT there's even more horsepower available if you want it! All you have to do is work for it a little.

The Evolution tuned pipe is a silenced type, and its very much on the "over-kill" side. The muffler portion of the pipe really creats a lot of un-necessary back-pressure at mid rance and topend. I'll walk you through how to extract the muffler segment, and release your engine's full potential. You won't be disappointed...

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Measure off 4 3/8" from the edge of your pipe & mark it. Cut the pipe off here using a standard pipe cutter.

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This will remove the muffler portion of the pipe and retain the "tuned pipe" segment.

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Remove the 3 screws holding the exit cap, and tap out the center section, from the opposide end. Its a little tight so don't be afraid to whack it!

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  Cut the exit cap off flush with the flange, debur and clean up the exit cap.

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Thoroughly clean the pipe and cap. I used a Scotch Bright and Disc Brake Cleaner to really get the parts clean.

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Install the cap using JB Weld. Let it cure for 12 hours. You're DONE! Let it cure and install the pipe back on your engine. Keep about 1/4" to 3/8" gap between the header & pipe. If you are not using a 16x8 prop, get one. I like APC but most any brand will work fine.

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Prior to my modification, I was getting 8800 RPM on its best tune, and it never "really" got on the pipe like it should. After removing all the back-pressure from the muffler... its now running at a rock solid 9400 RPM! The engine starts getting on the pipe right at 8900 and stays on the pipe all the way up to peak RPM. My benchmark prop is an APC 16x8. With a little pipe & carb tuning, you can push the little 26cc engine all the way up to 9700 RPM if you like. I don't recommend this, as you are exceeding the recommended RPM envelope. There is no mistaking when it gets on the pipe, as it provides an instant surge of power.  

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Here is a photo of my SCREAMMING   Rearwin Speedster powered with an Evolution 26 GT and my modified tuned pipe. The performance is incredable, and it's not really all that much louder. It is about 97 decibels at 1 meter, but its still quieter than a Pitts style muffler and it really cranks out some horsepower.

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Modified pipe 26 GT pulling my Rearwin Speedster through a super tight KNIFE-EDGE LOOP with power to spare!