Vetterman Exhaust with mufflers

I have the Vetterman crossover exhaust with mufflers and one heat muff on the right muffler. My Rv9A has an 0-320 E3D 150 HP engine.I flew for the first time in below freezing weather recently and just wanted to give a Pirep. I only had to barely crack open the cabin heat vent to warm things up quickly. Full open puts out tons of heat. I was concerned about my wife getting cold traveling but not any more. This setup is awesome. Thanks Larry.

Left side ?

Hi Jim,
What did you do on the left? i.e. I assume you used the second muffler, was the heat muff removable? Did you need to shield the cowl somehow?

Thanx
Darin

Yes I used both mufflers and one heat muff on the right side. I wrapped stainless sheet around the left muffler leaving about a third of the muffler open to the outside away from the engine to direct the heat from the muffler away from the engine and fuel line. This was per Larry's instructions. You won't believe the amount of heat I get from just one heat muff. If you open the heater vent all the way you'll think you are on fire. You could take a heat muff and cut all the material out between the inlet and outlet leaving an oblong hole and use that for a heat shield too. I didn't because I wanted to save the other heat muff in case I ever needed a replacement.
Here is the muffler side picture.

This picture is the left muffler without the heat guard.

Ignore the exhaust clamping arrangement. It was only temporary. Larry has very specific instructions for hanging the exhaust and it works perfectly.

I have two winters flying on my Vetterman mufflers. They are plumbed in parallel and supply ample heat for any cold. Warm feet and hands make for happy wives and she is always ready to go fly. The mufflers are one of the best investments I have made.

And the plane is quieter too. People can really hear the RV9 turbine whistle.

I was wondering, is there a hp penalty for having mufflers? I would think that it is not much but still wondering?

bird