Original Exhaust Modification anyone ????

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cheekykev
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Original Exhaust Modification anyone ????

Post by cheekykev »

Has anyone on here ever had a go at cutting the outer sleeve off the original exhaust on the welds around the ends of the main sleeve, strip the inner out and remake the inner to make it like one of the aftermarket ones i.e. put a 50mm perforated tube in it, repack it,. and then re-assemble the outer sleeve so it basically looks like an original one, but reacts like an aftermarket one.
Yes I know it sound like a load of messing, and no I've not been drinking :beer: I just fancy having a go :D and wondered if anyone else had tried it and could shed some light on the subject, or anyone with a view on whether they think it would work or not without causing any problems regarding the performance, fuelling etc
I must admit I do like the look of the original exhaust, the way they hang, plus the way they swoop up and inwards when viewed from the rear, problem is they're so bl**dy heavy :(
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Cadbury64
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Re: Original Exhaust Modification anyone ????

Post by Cadbury64 »

I tried the "drilling out the end cap" "performance" upgrade method, with 4 x 12mm holes in each. Did not like the sound that made much. A set of unmolested stock mufflers came up for sale and I grabbed these, only to find that someone had done some really neat surgery on them much as described in your post. From the outside they look stock, maybe just a touch shorter, quite a bit lighter, but they do have a nice deep but not offensive boom to them. I'd have to say the bike runs just as sweetly with these as with stock pipes, but sounds like a v-twin should. Image
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lloydie
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Re: Original Exhaust Modification anyone ????

Post by lloydie »

Plus the standard exhaust make it a little easier to loft the front wheel .
If your good with a cutter ,welder do it
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Varastorm
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Re: Original Exhaust Modification anyone ????

Post by Varastorm »

I used to do it quite a lot back in the day.

The method I used was to cut along the large diameter exhaust outlet end, at the weld.

I found That I had to use a 9" grinder, there's a lot of steel work in there to cut through, pipes & baffle plates etc.

I tried using a drill & chisel to "gut" the exhaust, but the amount of tubes & plates is crazy. The deeper you go the more things you find to remove, that's why they weigh so much.

I found the easiest way to "gut" the exhaust was to use a arc welder as a lance. Wind it up to around 140 amps with thin rods & in you go.

I used to cut around the baffle tubes first, then cut around the baffle & pull it out. Then the same again 2-3 times.

They are complicated inside, I was surprised when I did my first one. Just take care not to burn through the outer.

I seem to remember that the baffle assembly looked as if it had been manufactured as a stand alone item & slid into the chrome outer sleeve later & welded in. I think there are two skins, a baffle & outer chrome skin.

I found that the outlet hole dictated the perforated tube diameter, there wasn't a lot of choice back then.

Er, I mean there wasn't a lot of choice at the back of the local old exhaust center. We used to ask if we could look through the scrap exhausts & take what we thought would do & fill my dads car. Once home, chop them up for the perf tubes, two different diameters were used sometimes :lol:

I pushed the perforated tube as far as it'll go into the link pipe grinding it if need be so the transition from link to perf is as slick as possible.

Tidy up the inside of the end cap so it accepts the perf tube tidily. Pack the tube with Rock wool roof insulation making sure the perf tube is in the middle.

Place the end on (the right way round) & tack it on.

Take it for a spin & if you like it weld it up :thumbup:

It's a proper faf tbh.

But when your a kid with no money but plenty of time on your hands it's brilliant :thumbup:
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cheekykev
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Re: Original Exhaust Modification anyone ????

Post by cheekykev »

Update, well I got an exhaust for £22 off Ebay so I took it apart the other day and striped all the inner parts out of it.
Ended up cutting through all the welds :( even had to cut all the way down the seam on the outer sleeve, which now leaves me with a front inlet, a rear cap end and a empty sleeve hopefully I'll be able to do what I intended to do now.
So going to have a go at Tig Welding some of it back together next week, and if that goes well then I'll be on the look out for some 50mm perforated stainless steel tube, and some exhaust wadding, will probably make my own DB killer if required, I made one for the BMW and it worked a treat.
To be honest, after taking all the gubbings out, which there was a lot of, and bl**dy heavy, I think it should work out OK, plus a massive weight saving to boot :thumbup:
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Re: Original Exhaust Modification anyone ????

Post by exTRX850 »

Cadbury64 wrote: Wed Jan 31, 2018 12:19 am I tried the "drilling out the end cap" "performance" upgrade method, with 4 x 12mm holes in each. Did not like the sound that made much. A set of unmolested stock mufflers came up for sale and I grabbed these, only to find that someone had done some really neat surgery on them much as described in your post. From the outside they look stock, maybe just a touch shorter, quite a bit lighter, but they do have a nice deep but not offensive boom to them. I'd have to say the bike runs just as sweetly with these as with stock pipes, but sounds like a v-twin should. Image
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If the cans in the photo are the re-cut ones you've done well, they look great.

I may angle for the same...
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sirch345
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Re: Original Exhaust Modification anyone ????

Post by sirch345 »

cheekykev wrote: Fri Feb 16, 2018 3:35 pm Update, well I got an exhaust for £22 off Ebay so I took it apart the other day and striped all the inner parts out of it.
Ended up cutting through all the welds :( even had to cut all the way down the seam on the outer sleeve, which now leaves me with a front inlet, a rear cap end and a empty sleeve hopefully I'll be able to do what I intended to do now.
So going to have a go at Tig Welding some of it back together next week, and if that goes well then I'll be on the look out for some 50mm perforated stainless steel tube, and some exhaust wadding, will probably make my own DB killer if required, I made one for the BMW and it worked a treat.
To be honest, after taking all the gubbings out, which there was a lot of, and bl**dy heavy, I think it should work out OK, plus a massive weight saving to boot :thumbup:
I know someone who did have the standard can's gutted and a perforated tube fitted down the centre of each silencer. One thing I will say is they were rather LOUD, although not 100% sure if any packing was used, although I would have thought it would have been.

Good luck Kev with your mission :wink: :)

Chris.
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cheekykev
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Re: Original Exhaust Modification anyone ????

Post by cheekykev »

sirch345 wrote: Sat Feb 24, 2018 10:53 pm I know someone who did have the standard can's gutted and a perforated tube fitted down the centre of each silencer. One thing I will say is they were rather LOUD, although not 100% sure if any packing was used, although I would have thought it would have been.

Good luck Kev with your mission :wink: :)

Chris.
Yeah I get where you're coming from, I've taken that into consideration and have a contingency plan.
When I built my BMW Cafe Racer the exhausts were too loud, so I designed and made a DB killer/baffle whatever you want to call it with series of tubes and a perforated cone, and when I fitted them the difference was amazing, the sound from it was just perfect.
I am putting a slight restriction at the outlet end so I'm pretty confident that this will have the desired effect, if not and they're to loud I'll just copy what I did with the BMW.
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sirch345
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Re: Original Exhaust Modification anyone ????

Post by sirch345 »

cheekykev wrote: Sun Feb 25, 2018 10:15 am
sirch345 wrote: Sat Feb 24, 2018 10:53 pm I know someone who did have the standard can's gutted and a perforated tube fitted down the centre of each silencer. One thing I will say is they were rather LOUD, although not 100% sure if any packing was used, although I would have thought it would have been.

Good luck Kev with your mission :wink: :)

Chris.
Yeah I get where you're coming from, I've taken that into consideration and have a contingency plan.
When I built my BMW Cafe Racer the exhausts were too loud, so I designed and made a DB killer/baffle whatever you want to call it with series of tubes and a perforated cone, and when I fitted them the difference was amazing, the sound from it was just perfect.
I am putting a slight restriction at the outlet end so I'm pretty confident that this will have the desired effect, if not and they're to loud I'll just copy what I did with the BMW.
Seeing as you have made DB killers before I'm sure you'll have not trouble doing it again if your plan (A) doesn't give you what you're expecting :thumbup:

Good luck with it Kev,

Chris.
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cheekykev
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Re: Original Exhaust Modification anyone ????

Post by cheekykev »

Further update, well got them finished, I'm well impressed with the way they look :D just need to get them back on now.
I'd put some pictures up, but since photobucket did us over i haven't found another way of successfully posting picture up yet :confused
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Re: Original Exhaust Modification anyone ????

Post by Wicky »

Upload them directly to the forum's server.

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Best to resize them to something like 800-1000 pixels (width / height max) beforehand.

Online here http://resizeimage.net or install this to resize images on Windows PCs http://www.bricelam.net/ImageResizer/
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MacV2
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Re: Original Exhaust Modification anyone ????

Post by MacV2 »

cheekykev wrote: Sat Mar 10, 2018 10:35 am Further update, well got them finished, I'm well impressed with the way they look :D just need to get them back on now.
I'd put some pictures up, but since photobucket did us over i haven't found another way of successfully posting picture up yet :confused
I've been using imgur.com since the photobuket fec up... Easy to use...

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