dhutch
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| posted on 25/11/09 at 08:27 PM |
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Making an Exhaust Silencer
I need a new exhaust silencer.
- Tested at 110dBa at snetterton on saturday which confirms my thoughts that the current silencer (non repackable 4inch tin can of a thing) is well
past servicable. That and the fact i need to wear ear plugs on the road not to shout after a long trip.
Moneys tight (student, pah...) so ive been looking at making my own. I have access to tig equip but have only used oxy ace and odd bits of miging
bigish stuff.
I like the look of the paul gooderham can's with the brushed stainless and have also consider making the can from alummium with stainless
ends.
Bending the tube is the easy bit, ditto buying a lenght of perf tube.
But what actaully happens at the interface of all the parts.
- How does perf tube attach to the incoming tube?
- If it comes apart to repack, where does the split occur?
- Is one end left free to allow expention and separation?
- In which case how do you go about making sure it doesnt rattle?
Also, size. How big its too big?
- The engine currently a 1900(?) CVH although i would imagine a 2l zetec/duratec would be simular? And i thought i would aim to be able to about
98dBa. Most days are 105 but there are enough 102/101 days it might end up on one.
How would 6inch by 600mm sound? 2inch striaght through.
http://www.locostbuilders.co.uk/viewthread.php?tid=117456
Daniel
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mark chandler
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| posted on 25/11/09 at 09:15 PM |
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Mine is a gutted r1 can, behind the turbo its 98.5 db.
Ripped out the baffles, welded a bit of 2" tube to extend 1/2" into the body, this locates the perf tube.
One end on packed then rivited the top back on.
Job done.
Didi not buy perf tube, just got some mesh and rolled around 2" pipe and welded it into a tube shape.
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A1
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| posted on 25/11/09 at 10:28 PM |
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my mk one is really easy to repack, theres a cone shape welded on at one end of the can and the rearward end is rivited into place. the perforated
tube fits into a bit of pipe from the end of the cone bits...
[Edited on 25/11/09 by A1]
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rick q
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| posted on 25/11/09 at 11:16 PM |
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I've done the same thing with an R1 can. The only things I'd add to the above are
- a louvred pipe is a lot quieter than a perforated pipe. I faced the open end of the louvre towards the engine.
- pack the silencer with Stainless steel wool. Fibreglass and Mild steel wool disappear quickly in my experience.
- wrap the louvred core with fine SS mesh wired in place before you pack the silencer - it makes the fill last even longer.
- try to think of every way it can fail, and work around that. The finished result will then surprise you by finding another way to rattle itself to
pieces - they're very cunning like that [don't ask me how I know]
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Chippy
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| posted on 25/11/09 at 11:43 PM |
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In line with what I was told is best practice I made mine to the drawing attached, mine is 2.5", but easy to change to 2". The first section
is an expansion chamber, them a small area packed, then a larger area packed, the end cap is riveted in so the two packed sections can be slid out and
repacked. After all that work it's still bloody LOUD. Cheers Ray
 
Silencer Dwg.
To make a car go faster, just add lightness. Colin Chapman - OR - fit a bigger engine. Chippy
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dhutch
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| posted on 26/11/09 at 01:48 PM |
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Ok, interested in the expention section and how that works for you?
- Not a stupid idea at all, but i didnt think i was common to have anything other than a stright through with the perf tube. Maybe im wrong?
Are the additation intermedate ends then secured to the perf tube and just slid in to the can from the end?
Daniel
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A1
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| posted on 26/11/09 at 03:37 PM |
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to be honest, i found the standard silencer i have far too muted, and it was making the throttle response a bit slower, so i made a solid sleeve to
slide up about 75% of the perforated tube, made it much better.
that was cause the neighbors about 3 houses away moaned about the lack of silencer the people right next door said it sounded lovely
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Chippy
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| posted on 27/11/09 at 12:39 AM |
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I was trying to make a silencer that would do the impossable, I think. My engine as standard in the Ford car has five boxes to silence it, so two were
never going to do the job, just hoped they would be quieter than they are. I would say that on your engine a silencer of the type that I have drawn
would be very quite, and not restrictive regarding power production, a straight through silencer,with just perforated tube may be quite enough, and
again not restrictive on power. It just depends on how quiet you want it to be!! Regards Ray
To make a car go faster, just add lightness. Colin Chapman - OR - fit a bigger engine. Chippy
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