OzVMX Forum

Clubroom => Tech Talk => Topic started by: sudman on October 26, 2009, 07:13:32 pm

Title: 4 Stroke mufflers
Post by: sudman on October 26, 2009, 07:13:32 pm: Ok I want to build a muffller to suit my XL350, I have made the header pipe 1 3/4" now what's the best way to go with the muffler, any ideas?

Thanks
Title: Re: 4 Stroke mufflers
Post by: oldfart on October 26, 2009, 07:39:36 pm: Sudman , Think I posted what you are looking for last year ::)
Explained what I had used and how I went about it, I'm not the worlds fastest key board banger. If you get stuck I'll repost it ;)
Title: Re: 4 Stroke mufflers
Post by: sudman on October 26, 2009, 07:46:54 pm: Thanks any idea what the thread was called
Title: Re: 4 Stroke mufflers
Post by: oldfart on October 26, 2009, 07:56:10 pm: Just finished a cuppa so I should be good for 1/2 hour ;D
OD of large pipe is 76 mm - taper piece is 76mm X 50mm - blank 76mm - small pipes 14mm Id

(http://i72.photobucket.com/albums/i180/mutchoo/DR400mufflerparts001.jpg)
Title: Re: 4 Stroke mufflers
Post by: oldfart on October 26, 2009, 08:08:32 pm: Piece with holes drilled in , was re-drilled 6mm and more of .
I trimmed end blank so as to have 5 mm when butted to 76 mm round tube which gave me a nice area to weld .( not yet )
Then drill a 50mm hole and inserted the 50mm small section with folded edges and welded it to cap ( 50mm piece inside ).....cleaned up weld ...... then welded it to 76mm tube
(http://i72.photobucket.com/albums/i180/mutchoo/DR400mufflerparts003.jpg)
Title: Re: 4 Stroke mufflers
Post by: oldfart on October 26, 2009, 08:19:54 pm: Bunning has this ( 14 mm ID tube ) cut 6 pieces 50mm long and zip tie them together which will hold shape while you tack weld one end = 50mm OD
This is then welded to 76mm x 50mm concentric reducer - baffle is then welded to 14mm sections
which is then trimmed so it fits inside 50mm end blank ( supported )
I have done it this way so as it can be repacked at any time , and internal baffle is supported at opposite end
( Pause refill )
(http://i72.photobucket.com/albums/i180/mutchoo/DR400mufflerparts002.jpg)
Title: Re: 4 Stroke mufflers
Post by: oldfart on October 26, 2009, 08:23:20 pm: I have my muffler welded directly to tail section ( for looks ) with baffle being removable with a join mid section for ease of removal
(http://i72.photobucket.com/albums/i180/mutchoo/DRm370-1.jpg)
Title: Re: 4 Stroke mufflers
Post by: Nathan S on October 26, 2009, 08:59:16 pm: Best 4-stroke muffler has a straight-through baffle with an ID of 8~9mm.

Anything else allows them to sound like a f$%king 4-stroke, and should be avoided at all costs.
Title: Re: 4 Stroke mufflers
Post by: 211kawasaki on October 27, 2009, 09:12:42 am: where are you Shane???? 8)
Title: Re: 4 Stroke mufflers
Post by: mick25 on October 27, 2009, 06:18:01 pm: What about a gmc look a like that he makes for the HL500 it has a internal baffle, so there is no big muffler hanging of the back,or i have seen a two stroke muffler used on a xl350 it looked fine but it wasnt the org sweeper pipe,I have seen a few TT500s with big late models mufflers and they look out of place :o
Title: Re: 4 Stroke mufflers
Post by: MX? on October 27, 2009, 07:37:57 pm: What about the good old Supertrapp?
Ebay Item #120485164923 Needs a coat of black though 8)
(http://i.ebayimg.com/19/!Bdhu8Pw!2k~$(KGrHqUOKiUEq5eCr)Q)BK5RH7fw6!~~_35.JPG)
Title: Re: 4 Stroke mufflers
Post by: sudman on October 27, 2009, 08:15:02 pm: Thanks Oldfart I have made a start now, 1 3/4 header pipe stepping up to a mid section 2" power bomb then 1 7/8 into a 300mm long alloy can, as pre your design.
I will post the pictures when all done 8)
Title: Re: 4 Stroke mufflers
Post by: bazza on October 28, 2009, 11:22:44 am: supertrapp works with XL but use a lot of discs, Hey old fart are you going PC over there in Auz?? What is packing/ baffeling?? Let it roar
Title: Re: 4 Stroke mufflers
Post by: oldfart on October 28, 2009, 04:25:34 pm: Had same system tested at Cd5 with out packing and failed big time ;D
Title: Re: 4 Stroke mufflers
Post by: sudman on October 30, 2009, 06:23:10 pm: :DTwo nights in the shed & it's all done

http://s865.photobucket.com/albums/ab217/sudmanvmx/?action=view&current=camerapics013.jpg
Title: Re: 4 Stroke mufflers
Post by: oldfart on October 30, 2009, 06:40:45 pm: looks good , fired it up yet.
Title: Re: 4 Stroke mufflers
Post by: sudman on October 30, 2009, 06:59:10 pm: Yep sounds real good with a nice deep note, off to the VMX play track for a shake down to see how the whole thing goes