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Designing a Akrapovic ti replacement baffle


D

dragonclaw

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Joined
Sep 16, 2015
Messages
45
Location
Durham, UK
So I have a Akrapovic exhaust and i'm looking to design a baffle insert to replace the one already in. Just don't like the idea of modifying the stock one in case i want to use it again. I was going to take mine out and measure it but i went to take the baffle out and no luck. The baffle screw was offset from the out exhaust casing whole so it catches on the metal so i can't get it out.

I will get around to removing my baffle. In the mean time to get things moving could someone be nice enough to measure the baffle they have and pass the measurements to me. Main one being the outer diameter flange which has the captive nut on. Just then i can start CADing something up (My day job is a design engineer).

Once i have my prototype done (aka one for my bike) if anyone would like one i will get a batch of them machined if i get enough interest and see who much it would be. I'll stick some renderings up once i have it modeled.

Thanks
 
Sound good, but the only way to get the DB out us to remove the can....

If you use any tools on the 3 outlets they damage so easily...

I'd like to see what you could come up with.....

I took mine out, cut off The 3 internal pipes and welded a 48mm pipe on it.. Fits snug over internal 3 pipes that DB fitted to.. You cant see it when in.. Looks standard and not as noisy..
 
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I did manage to get the baffle out, half a broom handle and a lot of swearing but it came out. Had to drill the screw out being that it was off center, i will have to use a socket head instead of a button head screw which hopefully should fit.

After riding it 180 miles yesterday i can tell you it is way to loud. I love the look of the single outlet, reminds me of the side exit exhausts on race cars. I have come up with a design which I'm going to go out and get prices for at the local machine shops. MT09-Smurf is the 48mm ID or OD of the pipe ? Just my design basically is a pipe which has ID of 52mm to fit over all three of the pipes at the base and stays the ID all the way through. I have also ended the baffle where the stock collar finishes which houses the mounting bolt. Now with this design the back box still works the way it was designed. I'm hoping that having the baffle collect the gases from were the 3 tubes exit it will give a bit more of a deeper note. However because it is still getting pushed through the inner mesh it shouldn't be offensively loud.

Hoping to get it done in the next few weeks because i don't want to fit the stock baffle (right pain getting in and out) and I'm sure to get pulled with them out haha.
 
So i should be getting my new and hopefully improved baffle today from the machine shop. Just to give an idea of what it looks like i have attached a picture of the CAD model which i made.

baffle.webp

The 6 holes around the collar of for the mounting bolt, put six in just so it was easier to just to stick in without worry the hole is lined up. Also it is a 8mm straight through hole and the bolt will be held by a nyloc nut. Main reason being if you knack a nut you just replace it instead of having to re-tap the baffle. Hopefully having the three internal outlet tubes exiting in a tube will make a nice deep note without being too loud. I'm also hoping of some flame but i don't think it will do so haha.
 
It will definately sound deeper, mine does, but i have the 3 external outlets... I get the odd small flame, plenty of popping, would be interested in listening to this when in...

It will have no restrictions like the narrowing when forcing through the 3, should see some descent flames i reckon...

Looks good too.... So whats your verdict after fitting...
 
Got the baffle yesterday and looks the dogs. I am a sucker for a good bit of machined metal :)
WP_20151001_001.webp
The fit in the outlet is just perfect, slides straight in without any slop at all. I will post picture up tonight when i get a chance of the baffle installed. I have just started the bike in the shed and i can say it does sound nice, need to take it for a spin then i can make my final judgement.
 
Verdict is perfect. It's loud but it takes out the sharpness of the tone if it's straight through. It spits flame, not as much as straight through but enough to put a smile on my face. I have attached a picture of the baffle installed.
WP_20151002_003.webp
i also think It looks good as well. :)
 
impressive. I have my baffle inner pipes cut back and my sound is awesome. Without the baffle its too loud. So can i try your mark 2 prototype?
 
dragonclaw said:
So I have a Akrapovic exhaust and i'm looking to design a baffle insert to replace the one already in. Just don't like the idea of modifying the stock one in case i want to use it again. I was going to take mine out and measure it but i went to take the baffle out and no luck. The baffle screw was offset from the out exhaust casing whole so it catches on the metal so i can't get it out.

I will get around to removing my baffle. In the mean time to get things moving could someone be nice enough to measure the baffle they have and pass the measurements to me. Main one being the outer diameter flange which has the captive nut on. Just then i can start CADing something up (My day job is a design engineer).

Once i have my prototype done (aka one for my bike) if anyone would like one i will get a batch of them machined if i get enough interest and see who much it would be. I'll stick some renderings up once i have it modeled.

Thanks
Click to expand...

I felt the same about modifying the stock Akrapovic baffle (couldn’t return to standard), so I designed a simple replacement which I had machined in ally and then tapped a 6mm thread to use the original securing hole. Attached is my caveman drawing and pic of baffle in place. If you want the bike louder you can make central hole larger.
To remove existing baffle, I took off the end box, removed the 6mm securing bolt and used a length of 12mm dowel to knock out the baffle - it was a bit tight but moved eventually.
 

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Engineer1 once i have a finalized design i will give you a message. Just sorting out a few job related things first before i move onto the cheaper design. I can say after having it is for over a month now i am over the moon with the new baffle design. One of the designs i was looking at before this one Hoxton was like yours, however i wanted the exhaust to have it's wide open look. It's also nice to have a baffle that just slides in and out with out any hassle. Like i say version 2 is on the cards and i'm hoping once i have finalized it i will see about selling some if people want them that is.
 
Hi... How is V2 progressing.. Any update on design and cost..?



dragonclaw said:
Engineer1 once i have a finalized design i will give you a message. Just sorting out a few job related things first before i move onto the cheaper design. I can say after having it is for over a month now i am over the moon with the new baffle design. One of the designs i was looking at before this one Hoxton was like yours, however i wanted the exhaust to have it's wide open look. It's also nice to have a baffle that just slides in and out with out any hassle. Like i say version 2 is on the cards and i'm hoping once i have finalized it i will see about selling some if people want them that is.
Click to expand...
 
progressing, just started a new job so been busy getting back into the swing things so sorry for the late update.

At present I have the new design, the major change being I'm going away from it being machined and moving towards forming the baffle from a single stainless pipe. One worry I have is the tolerances, the machined baffle fits in perfect and I mean perfect. Expanding and swaging pipe to get the shape needed could result in bigger then wanted tolerances. However I won't know until I get my prototype v2 which is being made and I'm hoping will get here before the Holidays.

As for price doing it the way I am looks to cut the price down from £150 to £20-30 which I think is a lot better of a price.

I'm hoping once I'm 100% happy with it to start producing them January/February.

If people are interested and might want one stick a reply within this thread then I can get an idea of what number I could be looking at producing. Also if I can do batches it could bring the cost down per unit.
 
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