Trans fluid hard lines make great dual exhaust!

[forest rex]

I did a 5 speed manual swap on my Subaru Forester and had some PCV tubing and the auto trans fluid (ATF) cooler hard lines laying around, so I figured I might put them to use:

They clear the pedals, the tube doesn't melt, and it looks cool. It doesn't really improve performance because you're still restricted by the stock muffler, but it doesn't hurt anything.

But the best part is it keeps oil from being sprayed on my shoes.

 

[bluegoatwoods]

Pretty ingenious.

Maybe you could open up the inside of the stock muffler a bit to get things breathing a bit easier.

Then maybe add some sort of lawnmower exhaust out at the ends in order to quiet things down a bit?

 

[forest rex]

I actually did cut off a bit of the pipe inside of the muffler and my top speed increased by 1 mph with a wider power band, but I also did some carb tuning at the same time which was probably the bigger reason for the performance increase.

Honestly, the clutch is just as loud as the motor. I might go get a sample of acoustic dampening foam and put it around the inside of the clutch cover and crank cover.

When I go to college next year I think I'll probably get another supplementary muffler to quiet it down even more.

 

[MEASURE TWICE]

I'd guess the muffler has enough surface area that there is like cooling fin effect.

I was looking at that material that is covering the hard line of some kind of metal, the covering I would guess is rubber or pvc or something that I would expect to melt.

So it does not melt but in hopes of getting less back pressure you have the T fitting for twin exhaust and also keeping the exhaust oily spray away works.

I have a Briggs 3hp 4stroke and now use the corrugated stainless steel water pipe and adapters to my exhaust out under the back of my banana seat. It is hot enough to burn at the muffler at the end, but not that the seat is affected. I plan on putting a screen over the muffler so you cant touch it directly, but exhaust comes out and heat is not trapped.

I removed the gaskets of rubber for home made copper ones in the corrugated stainless steel water pipe. I also removed galvanic corrosion prevention nylon plastic sleeves from the water pipe.

The volume is better with the extension at idle, but when reved up it is still fairly loud.

MT

 

[forest rex]

The hard lines are just painted black. Even after flogging the motor, the pipes are warm, but not too hot to touch by any means. If the PCV hose coming right off the stock muffler doesn't melt, nothing else should melt either.

It seems to direct the volume more out the back, which is good.

 

[MEASURE TWICE]

I have a lot of protective covers over moving parts so sheet metal vibration is some thing that adds besides exhaust and intake sound. I may see about putting something to dampen the vibration like a bolt end with a rubber bushing pressing against the covers on available space inside the covers.

A 10 inch diameter spoked pulley spinning between 700 rpm and 1200 rpm by by leg and carb linkages otherwise open to the elements trail riding, dictates I need covers that I made. I'm even thinking to fully cover over an area that has sprockets and a short section of chain. It should have access to lube but keeps out rocks and dust.

MT