Silencer Repair for Dummies

[Ji Gantor]

Hi Slawesy,
It is raining today so I can not finish.
Will get to it over the weekend.
I hope what I show will help.
If you are in Queensland and need some help let me know.

Ji

[Lozza]

Hi Lozza,
Have you found what horsepower or torque gain there is if the silencer works as designed.

Ji

A general rule is short = more bottom end longer more top end. Short is 250mm long is 290mm  Making sure you don't loose HP and pass noise test is the trick

[Ji Gantor]

Thanks Lozza,
When dynoing is there any marked diff on power with or without a silencer?

Ji

[GMC]

There are no restrictions on materials or shape for a muffler, some just look better suited than others.
If your going to “skin” the muffler with aluminium then their wouldn’t be any reason to cut up the original as you would end up replacing everything anyway.
Good originals can be sought after by the guys doing the original resto’s.
I have repaired a few by grinding down the 2 seams of the muffler to take it apart. You can then remove dents, fit a new core, repack and put back together again. You can make them look like new again but I wouldn’t like to do this more than once as the seam gets too small to be able to reweld too many times.
Ji’s way of fitting an end cap will make them easily repackable.

[Lozza]

Thanks Lozza,
When dynoing is there any marked diff on power with or without a silencer?

Ji

Not something I have spent time doing. A contact who spends lots of time on this stuff found a combination of hole size and spacing that kills dB and actually made more power. I have no reason to doubt his findings.
Again in general a well designed silencer will only enhance output

I see no issues with CF mufflers. I'd have them on all my bikes if I could

So I'll have to make some more then? Is that the third bike it's been on Doc?

[DR]

Loz noooo, the mufflers I'm using (as pictured) are Rod Tingate RGV250 items I scored from an ex race bike. They cut noise quite considerably and weigh nothing. Yours was much smaller in diameter

[firko]

Commercial welsh plugs make ideal end caps

I've used welsh plugs but they're usually a bit thick. I found industrial trolley wheel hubcaps lighter and equally suitable.

[odd1]

Can someone tell me how you make a dome cap using a Tig welder?

[Ji Gantor]

Hi Odd1,
The end cap will not be domed.
It will take on the apperance like a walsh plug if you like.
Using standard pipes and plate all welded together.

Ji

[odd1]

Basicly you are making it in segments?

[Ji Gantor]

Yes
One large outer pipe
One smaller inner pipe and
A flat plate disc all welded together.

Ji

[odd1]

Ok Thank you

[Ji Gantor]

I will finish this topic this weekend if it stops raining.
Photos and how I did it will accompany.
Certainly not as good as Oldfarts front number plate holder, but I am getting better.
Oldfart I will strive to raise the bar to your level, it may take a few years.

Ji

[E74]

Mmmmmm Iced Vo-Vo's 

[Ji Gantor]

Hi E74 is this a good time to ask about those Z spokes

Ji