Topic: homemade exhaust

[Dakotarider]

My 350f had a rotten exhaust so I removed them at the header pipes.  VERY loud and ran like crap midrange rpm.  I found some instructions here to create a baffle with wire screen and steel wool.  Wrapped the screen around 1/2" rebar for its form and then wrapped that in steel wool.  Pulled out the rebar and shoved the "baffle" into a 1"x6" piece of copper pipe from the plumbing section.  This then fits perfectly inside my header pipes, secured it all with a sheetmetal screw
Sounds great now and has a nice smooth power all through the revs!
One question, I guessed on the 1/2" opening and am wondering if that is too much back pressure creating problems down the road?
I'll post pics soon.
thanks

[Tracksnblades1]

Personally, I don't like smaller exhaust openings than stock and prefer larger based on engine requirements.

Some, I've read,  suggest never to go smaller than the exhaust valve size (1).

[Dakotarider]

I did have it wide open and that meant no back pressure causing the midrange cutting out.  How big of a diameter would be the stock valve size then?  Did you mean 1"?

[pjlogue]

Using steel wool, it will rot out very quickly.  If you use stainless steel wool it will last longer.  I have a straight through exhaust on my GL1000 (4 into 1) that didn't have any packing in the perforated tube so I used the SS wool.  It is still holding up a year later. 

-P.

[spotty]

also the steel wool will spray out the back as molten flecks of red hot sparks, not something the police or park rangers ( something to do with starting fires in national parks and the like) are happy to see

its only visible at night but boy is it visible

try using the fibreglass repack kits that are common use in enduro/mx bikes, this sort of thing, it can be wrapped round a perforated tube, wired on and slid inside the "muffler"

https://www.ebay.com.au/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=muffler+repack+&_sacat=0

[Gurp]

Look up a "lollipop" baffle easy to make and will give you a good lasting baffle

[Tracksnblades1]

I did have it wide open and that meant no back pressure causing the midrange cutting out.  How big of a diameter would be the stock valve size then?  Did you mean 1"?

No honestly I don't know what size your exhaust valves are. I should have wrote no less than the diameter of one exhaust valve should be the minimum. I do think on a bike the factory turned 10k she'll let you know when it's too restrictive. Above a member wrote of stainless steel last longer, agreed as well as those SS scrub pads for washing pots and pans.

It's good to read fabrication is still alive and at home.


😎

[Dakotarider]

I'll take a pic of what I did, good idea with the stainless or packing.  So far it is still running smoothly.  I love the fab stuff out of cheap everyday materials.  Got a spare parts motor to check the valve size on tomorrow.

[Don R]

 Guys used to put VW beetle exhaust tips on them.

[754]

Yup straight tips and the horny taper tips..
Whoo..Hoooo you can still get 4 chrome tapers for around 50 bux..!