Malibu 247 8.1 muffler delete.

April 13, 2020

I've had FAE exhaust for years and always wanted to get around to a muffler delete. 1, because the muffler kind of becomes redundant with FAE, and some people noticed a bit of a power bump, and/or an actual sound decrease from the engine bay. Both of those sound good to me.

Finally found time to get it done. This was just a quick fix, and most certainly not the cheapest, or most extravagant way to get it done. But the ease and time of putting it together was the main driver of my product selection.

I didn't like the FAE muffler delete with the mitered 45* angles... The high performance engine guy I am would let that happen.

The cheapest acceptable way to me would be to get about 4' of stainless and make a bunch of 7.5* pie cuts, form the proper s bends, and then weld away... Probably less than $100, but would take me at least 8 hours a side, cutting, welding, and running back and forth to boat for test fits.

I decided on a combo of metal and rubber 45* bends to get the job done. The 8.1 has a 4" tube coming out of the exhaust riser to muffler input, and a 3.5" outlet from muffler to transom exit. So I went with a 4" stainless mandrel bent 45, a marine rated 45* rubber elbow, and a stainless 4" to 3.5" reducer. I cut off 2.25" from the rubber 90* 3.5" hose that went from the muffler to transom exit, and put in new 7.5" long (factory length was 9") 4" hose from the riser to the stainless 90.

The stainless 45* bends were $56 each (vibrant 13104) Amazon

The rubber 45* elbows with clamps were $62 each. (Trident Marine. Amazon.)

The 4"-3.5" t304 stainless reducers were from ebay $20 each.

So $276 before tax.

I ended up cutting 3.5 or so inches off each end of the stainless bends. Turned out nice, and probably 4 hours max putting it together.

I started it up on a fake a lake, but didn't put it in the water yet, so I have no idea what difference it makes. I'll have to update in a few weeks.

In this pic from top to bottom:

1. 3.5" Rubber 90 transom exhaust exit to muffler

2. 4" - 3.5" reducer

3. 4" 45* rubber

4. 4" 45 stainless

5. 4" straight rubber to riser.