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Discussion Starter · #1 · (Edited)
most people know that the stock muffler on bikes is about as restrictive as you can get. this will turn it into a race baffle, ala HPE, MIVV, etc. except this will look stock, and not like crap (who the heck came up with the MIVV design seriously) this is fairly easy on most bikes, not as easy on benelli. heres where im at so far.

start with this



drill the back studs out



tap the black end cap off with a rubber mallet

cut the welds



then the guts come out with a good yank, or drop it on its end



it is all attatched so you will want to cut here




you guys are a step ahead since you can order the parts before hand, unlike me. i had to take it apart to measure the inside piece to get a core kit the right size. that measurement youve all been waiting for. 2 inches. you will want a piece of stainless perforated tube in that size.

i will show assembly when that piece comes in.

not shown is the fiberglass inbetween the layers. SAVE IT, but try to not handle it too much. also if you want a quiter exhaust buy an extra packing kit or some steel wull. (use it OUTSIDE of the fiberglass packing)

ALSO, this is the HARDEST stainless ive ever worked with. so take you time and find a friend with a band saw to make the cut through the back.

this mod should be equall in flow or better then a slip on and costs less then 50$, as apposed to 400$ for the ugly MIVV and 500$ for an HPE that would require me to build yet another new tag bracket.
 

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Great post Zed, Ive been looking for a second hand can lately to do just this, so its great to see what you have done

When you look down the inside what do you see?

I take it your not a fan of the Mivv cans then:D

I also thought about polishing the can and end cap, then painting with a clear high temp laquer if there is such a thing
 

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Discussion Starter · #3 ·
inside the muffler chamber is a triple pass system. 2 seperate chambers and 2 total direction changes of the exhaust gasses. its also totally sqaured chambers with the tubing passing deeply into the chamber. best for muffling sound and dirty air. worst possible design for performance.

yeah i would rather leave the stock can totally stock then mount the MIVVs

i think i will polish the can and leave the cap black so that exhaust doesnt show up on it as bad. you can clear it but no matter what clear you use it will eventually yellow from the heat. best practice on this would be to just keep it good and waxed. once every 3 months should be fine in most climates.
 

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Zedicus

inside the muffler chamber is a triple pass system. 2 seperate chambers and 2 total direction changes of the exhaust gasses. its also totally sqaured chambers with the tubing passing deeply into the chamber. best for muffling sound and dirty air. worst possible design for performance.
can you post some pics of the internals plus measurements of internal pipe lengths/diameter plus position of chambers in relation to the overall can
Question in relation to the pipe size, supply pipe to the muffler on the Tre-K is 2.36" (60mm), why reduce the internal pipe to 2" (50mm) as per your previous posts
Regards

Tuono
 

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Discussion Starter · #5 ·
2" is the easiest way to go with out major work. the stock insides go down to 2" (just inside the muffler) then about 1 inch and then exit as 1.5inch. i can try and get some detailed pics tonight.

trust me though, you could go down to a 1/2 inch straight through internal baffle and be less restrictive then the chamber design that is in there.
 

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trust me though, you could go down to a 1/2 inch straight through internal baffle and be less restrictive then the chamber design that is in there.
Quality:D love it
 

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zedicus, if I understand your description correctly and more questions

2" pipe from front of muffler thru to the back chamber
-is this reduced at the chamber divider?
1" exit pipe back to the front chamber
-what length is the pipe either side of the chamber divider?
1.5" pipe from the front chamber to exhaust exit
-what length is the pipe from the chamber divider to the front of the muffler?
there is no material - fibre glass, steel wull inside the chambers?

Regards

Tuono
 

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Discussion Starter · #8 ·
2" from back to first chamber, this pipe is roughly 9" long and angles to one side. goes all the way through to the rear chamber. this gives about 2 inches of overhang into the chamber.

then there are 2 1" pipes that cross the divider, these are about 4" long, giving about 2" of overhang on each side of divide. again the angle matching the angle of the inlet piping.

then the outgoing pipe is probably 12" long counting the tip, this is the worst one yet. maybe 1.5" barely. matches angle of other pipes also. plus the over hang, plus it has a bend on the inside of the very back edge to get the tip to look straight, plus the tip has the slight angle down.

the chambers are totally empty, they use the overhang of the pipping to create the baffling effect.

there is some fiberglass wrap, it is around the entire stainless chamber, in between it and the aluminum shell.
 

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The overall design sounds close to the Buell firebolt can, from memory the mod for those was a perforated pipe finishing at the back chamber, removal of the pipe returning to the front chamber and cutting the exit pipe flush at the chamber divider.

Tuono
 

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Discussion Starter · #10 ·
The overall design sounds close to the Buell firebolt can, from memory the mod for those was a perforated pipe finishing at the back chamber, removal of the pipe returning to the front chamber and cutting the exit pipe flush at the chamber divider.

Tuono


thats more work for less gain, race baffles are straight through. and i fired this thing up with no muffler on it at all just to see and its really not that loud. my last bike was a superhawk with D&D cans and it was louder then my TNT with nothing after the head pipe. so im thinking a real race baffled can is not going to be bad at all.
 

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Discussion Starter · #12 ·
a 2' baffle down the middle, all im using for packing is the stock fiberglass, if you wanted quieter you could add more fiberglass mat. i will do detailed pics when my perf tube comes in. had to order it, no one in town carried the stuff.

another benefit is this exhaust will be 10-15 pounds lighter then stock.
 

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6kg lighter thats a bonus

that makes the bike 193kg dry and it comes off high up so you should be able to feel the saving
 

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zedicus

2" tail pipe section also?, or will you leave the tail section standard?
why only fibreglass mat? and not a combination of steel wool mesh and fibreglass mat?

Regards

Tuono
 

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Discussion Starter · #15 ·


theres why, in order to go iether size all the way i would have to cut the center out of a piece that is the thickest hardest stainless ive ever messed with, then weld in a new straight through adapter. plus the 0.04% you are going to gain by going from 2" to 2.5" all the way through is absolutly not worth the effort. your only going to have about 14" of 2" anyways. and its about 100000x better flow then stock chambered design.

as for the packing, IM not going to add more packing becuz around here this bike with a truly open header is not even close to loud. so theres no reason to use more packing.

heres some background info, this is a farm community. ******* and hicksville through and through. theres literally x10 more cows then people out here. what i am competing with on sound levels are open pipe harleys, other crotch rockets that have no baffles, or pure race exhausts that the kids ride around balls to the wall in first gear. also there are mud trucks driven around the streets daily, these are mostly 350 chevy or fords with fairly high compression and no cat or muffler, just straight shot out the back. it gets better too, you guys ever hear an irrigation engine held WOT running on methane with long tube headers and nothing after the 4" collector???

so what im saying is, comparably, nothing i could do to the benelli would make it loud, as such, theres no reason for me to add packing. depending on your environment, adding extra packing may be the right thing to do.
 

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theres why, in order to go iether size all the way i would have to cut the center out of a piece that is the thickest hardest stainless ive ever messed with, then weld in a new straight through adapter. plus the 0.04% you are going to gain by going from 2" to 2.5" all the way through is absolutly not worth the effort. your only going to have about 14" of 2" anyways. and its about 100000x better flow then stock chambered design.

as for the packing, IM not going to add more packing becuz around here this bike with a truly open header is not even close to loud. so theres no reason to use more packing.

heres some background info, this is a farm community. ******* and hicksville through and through. theres literally x10 more cows then people out here. what i am competing with on sound levels are open pipe harleys, other crotch rockets that have no baffles, or pure race exhausts that the kids ride around balls to the wall in first gear. also there are mud trucks driven around the streets daily, these are mostly 350 chevy or fords with fairly high compression and no cat or muffler, just straight shot out the back. it gets better too, you guys ever hear an irrigation engine held WOT running on methane with long tube headers and nothing after the 4" collector???

so what im saying is, comparably, nothing i could do to the benelli would make it loud, as such, theres no reason for me to add packing. depending on your environment, adding extra packing may be the right thing to do.
A Benelli in Kansas! I understand your situation completely, you might as well be an alien out there with a Benelli.:rolling: Your description sounds like "Anycorntown" USA, which is where I'm originally from (midstate Illinois:bluesbros: )Corn, soybeans, 4x4's, Harley's' and dive bars! Hurry up and get that exhaust done...I will probably do the same with my soon to arrive Cafe Racer!:ele:
 

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post a sound clip when done it would be interesting to hear your mod is like we did to buells standard pipe ,keep us posted
 

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zedicus

how's the muffler build going, as you had to order what thickness, hole size and pitch did you settle on for the 2" pipe

Regards

Tuono
 

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Discussion Starter · #20 ·
pipe showed up, the only stuff i could find is 40% open area, 1/8th inch holes i think is what it was. i ordered from here. http://www.lachoppers.com in exhaust on page 2 there is perf tube.

i made a cut i shouldnt have so im waiting to catch up with my welder buddy to get it all sorted. hopefully this week sometime as i would like to ride it a couple more time before its frigid out.
 
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