i took delivery of my $3 pipe!
going to do it this afternoon.

 

Here's a little clip, crappy sound and videography. Actually contemplating opening the top of the exhaust and cutting the inner pipe back to the baffle, have to run it by my welder and see if he's up to helping out.

It sounds better in person and when you're riding.

 

Actually contemplating opening the top of the exhaust and cutting the inner pipe back to the baffle, have to run it by my welder and see if he's up to helping out.

What do you mean by that exactly?

 

Nice vid, sounds great. Maybe a little louder than mine?

 

Have you noticed anything wrong/improved about the throttle or overall riding experience?
It sounds great and looks easy!
Nice idea....

 

Honestly, the fueling and throttle response feels exactly the same to me either way, just like stock. If it got leaned out, I can't feel it. But it doesn't feel any faster either, just some more volume.

 

well i just wanted to tell you that i sort of did the same thing! So here's what happen. I bought and installed the M4 slip on exhaust . Piece of cake! I guess i should start by saying that I'm 58. I was thinking that it would be nice to get a little beefier sound out of my bike, well it worked . the M4 really does sound good but i wasn't crazy about hearing every little variable in in rpm's when going through town at elevated decibels. I think the stock exhaust sounds pretty good but more importantly it's how the bike was designed to run! Anyway, long story short i had to pay a welder to re install the the Cat/muffler that i cut off. So after seeing your thread i decided to try get a deeper tone by installing a larger tail pipe. Well....I'm not sure if it worked or not! After riding for a week with the M4 i forgot what the stock system sounded like. If it did change it wasn't worth the work. What the hell, it was chump change for the labor. I used a section of oval pipe from a stock Honda 600rr. I did have to take off the tail pipe end , kind of a pain drilling out 3 rivits . Also had to extend the the oval shape hole with a Dremel.

It was worth a try !

 

Well, I wanted to get a bit more volume from the FZ, but wasn't ready to take the plunge into an M4 or other system. So, I gave this mod a try. Since I was a bit skeptical and the feedback so far is that it is very subtle, I figured I'd try to get some before/after footage to see if any differences could be documented for my own confirmation and to try and avoid false impressions.

I did a simple hack job (literally, I used a hand hack saw), preserving the shroud mounts, and just re-mounting the shroud with no replacement pipe outboard of mounts. At least this way, the shroud isn't just cosmetic - it is now really a part of the exhaust and may be acting a bit like a megaphone.

After doing the mod, in person, I did seem to notice some effect - it is noticeable, but subtle. It seems slightly louder and with a slightly deeper tone. Unfortunately, the GoPro (in partial wind, with auto level controls, in a vibrating plastic box, etc) does not document any difference, at least not to my ear. I even edited the video so similar parts of my test loop are in sequence - stock and post-mod - but if you can hear a difference, you are doing better than me.

All in all, I'm glad I did it and it will probably do for a while - at least until I can hear some aftermarket systems in person.

Thanks again to Stellmon for the original idea/work/posting. :thumbsup:

 

Is there any new updates to this thread that we need hear about?
Do you think the 2015 will deliver a larger tip exhaust path?
At 6000 in 2nd , how does it sound?
Any new tip ideas megaphone styled, keeping the cheap and retaining the look of original stock.

 

I just did this to my bike the other night. I used a 2" OD tube that was expanded to a 2" ID at the end and then fish mouthed it around the bulge left after trimming off the stock tube. I did cut back the inner tube about 3/4" as well. welded it all up and then taped off the chrome section of the header and used 1300°F header paint (matte black) to paint the exhaust from the collector back. I kept the cover stock and mounted it all back up. Looks great with the matte black rather than the weird plating that is stock.

Sound is great, much throatier and quite a bit louder. still not like the Vance n Hines I had on my old Suzuki that was way louder. Sounds great at idle and off idle. Hard acceleration if quite a bit more than stock but cruising at 65 - 70 you hear it but the wind noise beats is louder still, so nice and reasonable there as well. Great mod I love it and it only cost me $15 for the paint and the pipe. 3 hours to do the whole thing as well. (I have the welder at home and power tools etc..)

Thanks for the idea! if anyone is contemplating this and wants the extra volume for free, trim the id and enjoy!

 

I just did this to my bike the other night. I used a 2" OD tube that was expanded to a 2" ID at the end and then fish mouthed it around the bulge left after trimming off the stock tube. /QUOTE]

I'm pretty sure legally you have to post pictures at this point.

 

Do you sound like a vanquish or a 70's bug with a hole in the muffler? Can you ride around downtown , first gear about 7,000 rpm and not get pulled over?
Is there residue or smoke or any flames happening? That pod or can must be knocking out flames and fire pops .You opened up a hole , so I'm asking about the exhaust function. I can't seem to get the exhaust system I want now and might do this tommorrow or Monday. The thread is seven pages and still seems like it needs more , video and measurement and pictures and opinions and going beyond the tip into color.

 

I'm going to be doing this to my MT, new tail pipe, will open up top and see what else can be done, I presume the cat is just behind the collector, wonder if you just cut the muffler off, you would be able to get in there with a long screwdriver and a hammer and chip the thing out, someone who has put an new exhaust on and doesn't care needs to section the muffler in half (horizontally) and see whats in there, that would be a huge help for owners contemplating mods, the bike is not short of power, some more bark would be nice, and get some heat out of the engine would be another bonus.

 

For all out there who want to know what lurks beneath here are pics of the inside of the rear section, this is as far as i want to go with it, i have left the cat intact and i presume there is still more internal baffles inside.As you can see i cut a trap door in the top and found one pipe going to exhaust exit and two more stubby pipes,so i thought what the heck i will cut the exhaust exit pipe and leave it like the others.I don't know what it will sound like yet as will have to wait until tomorrow to get it welded back together.

 

For all out there who want to know what lurks beneath here are pics of the inside of the rear section, this is as far as i want to go with it, i have left the cat intact and i presume there is still more internal baffles inside.As you can see i cut a trap door in the top and found one pipe going to exhaust exit and two more stubby pipes,so i thought what the heck i will cut the exhaust exit pipe and leave it like the others.I don't know what it will sound like yet as will have to wait until tomorrow to get it welded back together. View attachment 9242 View attachment 9243 View attachment 9244 View attachment 9245 View attachment 9246

Awesome, theoretically this will allow better gas flow as well a noise as all three pipes are allowed to flow rather than just dumping noise , could someone post a photo of the inlet to the muffler when they get in hacked off for the M4 conversion, shine a light down at as well so we can at least figure out where the CAT is, cheers

 

Or you could just get one of these -

If you're wanting more technology then this is available for the iPhone and Android users.

 

I predict awesomeness. Post a video of the sound when your done.

 

Let's hear this thing already.

 

The new accessories page has a carbon fiber exhaust cover. The original looked good to me but the other section discoloration is bad. On its sidestand leaning it isn't so bad but upright it is noticeable. I am surprised that a larger exhaust tip kit has not shown up and also a discoloration plan.

 

The new accessories page has a carbon fiber exhaust cover.

That damn thing is $200 !!!

 

The way one pipe is designed, it has the gas flow going back FORWARD. Interesting. The long pipe clearly is the exit. The shorter straight cut one must be a cross pipe between the front and rear chambers, going from the front back, while the flaired one allows the gas to go back forward to then exit with the final pipe that goes out? (Is the longer bent one that goes directly to the exit pipe.)

My guess, having not seen the front chamber yet, is that the collector dumps it into a cat, that then dumps it into a second chamber with one pipe with a flaired end going to the tail pipe, another shorter flaired pipe that dumps to the rear chamber, and the return pipe from the rear chamber that has a straight cut end, and might even "Y" together with the exit pipe in the front chamber. This Y would have a scavenging effect on the rear chamber as the gas flows out the main exit pipe.

In any case, there is some serious sound deadening/wave cancelling effects of the stock muffler/pipe system.
Might even help with lower rpm tourqe, while it limits top end power some, but not much, since the big dollar straight pipe systems only pick up a few hp on top, and only really then when they are tuned. (Tune the stock pipe, and it's going to result in some power gains too.)

The open pipe mod might work better if you leave the exit pipe as long as you can, but open up the hole around it, and then extend the new hole with the new pipe. This creates a scavenging effect on the main pipe, in effect, sucking gas out the rear chamber as the faster moving exhaust gas from the main pipe is release up the new larger pipe around it.

Indeed, if you took the stock OD tail pipe, cut it right, and WELDED it to the inner pipe, while leaving say a 1/2" to 3/4" gap around it, and then used a larger 3 to 4" OD pipe crushed to get the right "oval" shape at the tip to fit, might just be the ticket to the best possible exhaust flow out of the stock pipe design, and might even make gains over some of the straight pipe systems with a Db killer fitted. (While being as quiet, or more quiet.)

Going to have to try some mods on this for sure. A slight taper/bell design would accelerate the exhaust gas from the main pipe, and really get the rear chamber clearing effect going at lower RPM at the expense of some top end power, but it would be worth it for more tourqe in my book, since this bike is all about the off the peak power anyway. (Think of a jet engine in the pipe, it's going to pull more gas around it as the center jet accelerates the gas, and draws more since it's faster now than it was without the funnel/taper/bell effect.)

 

If you don't like the color, just paint it with high temp black. (Or really go all out, and coat it with ceramic paint that has some thermal barrier properties, and will not only look nice, but result in cooler outside temps around the muffler and any coated pipes.)

A well designed skid plate that bolts to the muffler, and some hard points on the engine, would result in a very strong design that protects the engine oil drain and looks better than the stock welded up "can" we have stock.

The stock exhaust is nice and quiet, and seems like it has plenty of power compared to the dyno charts showing that only a few gains are reality. It would be interesting to see if a slightly modded stock exhaust might make the same gains, especially with a custom tuned ECU program for that specific bike/engine.

A few decibels of sound would be fine, but I really don't need any more power from this bike/engine. It's nice and light, and for a "Supermoto" that I consider it to be, plenty of fun.

I have a welder. I used to coat parts for fun, and I've done a few exhaust manifolds with various ceramic coatings from Techline coatings. They work great, and hold up to real world use better than expected. Cutting off the stock pipe, and going to a larger one, with the stock bent pipe going up the middle of the new larger ID one would result in the most flow based on fluid dynamics laws. (The center pipe would in reality, scavange gas out of the larger case with the two pipes going forward and back.)

What would that do to the sound? I'm sure it would be slightly louder. I'm also sure that I'd make the pipe nearly the size of the "cover" and just cut/modify the end cap so it fits the new taper/slash cut exit. Just eyeballing it, you might be able to run a 3" ID pipe with a slight crush to ovalize it before you grind the slash cut to fit, and open up the cap to clear the new larger tail pipe.

ON the idea of the skid plate, a stainless one would be strongest, but aluminum would be lighter, and might be all you need to protect the concentrated impact force that would crack the oil pan. (Spread out the load, and create a smooth surface to slide over curbs or whatever you run over, and it's going to do it's job just fine.)

 

Stellmon - Holio or anyone else that may have any thoughts on stock muffler mods. Just wondering how your bikes are preforming and how do you rate the increase in DB levels. I like the Akra Ti system but don't want to spring for the bucks. I don't think the stock system looks too bad and I'm happy with the stock performance. Just looking for a little deeper throat to the sound. Not too loud but a bit more burble. I'm thinking of going with the pipe above the bracket fix and if that's not enough going with the Holio muffler cut approach. Any info would be helpful and has anyone else done something different than these two approaches?

 

Adjuster...Let me see if I understand you. You say to cut into the muffler around the exit pipe and leave that pipe long as possible while welding another pipe on to the muffler hole that was just cut which would give you two pipes extruding from the muffler. One is the original exit pipe and the other would let the flow out from the chamber that surrounds the exit pipe. If it was shaped properly there could be two pipes at the end of the cover. Or would it be best to have the outer pipe longer than the inner original exit pipe? Sounds like a little more work but if you think it would create a better note without not needing any other adjustments I may give it a try.

 

Just did the Versyrider version of the Stellmon mod, as mentioned in earlier pages. I didn't weld a new pipe on but just slapped the cover back on. Will do when the snow is coming down again next winter. I must say it's AWESOME. My bike is noticeably louder. I would estimate a couple of DB's and about a half or a full octave on the bottom end burble. Sounds like a motorcycle. Sweet Music! You can hear the downshifts at the higher speeds and it's certainly not too much. I think it's just right. In fact I estimate it saved me $700 to $1100 on a better sounding system. Performance wise I noticed no difference from low speed acceleration thru 65-70. To windy around here today for anything more. The extra noise seems to flatten out at the higher cruising speeds. Possibly has something to do with the back pressure?
BTW: Another Idea for comment...I was thinking of drilling a few holes in the section that extrudes from the muffler to the first weld. My thinking was that I could tailor the sound depending on how many and how big the holes were. Went for the other version instead but all in all it sounds perfect for my needs.

 

Just did this. Cut at the first weld to keep mount then used dremel and cut the inside pipe back deeper to where the main chamber is more open. MUCH louder than stock! Love it. No urge to buy an exhaust now. I love the tone. Video, at least on my phone, doesn't do it justice. But very happy with it.

Hit it with a little black paint to cover the cuts.

.

 

Inside the box.

 

A follow up on my exhaust mod. Rather than to put the stock pipe cover back on I decided to do something a bit different. I got a muffler pipe reducer from autozone, cut some slots so that it fits between the welded pipe cover mount and made an exhaust tip. I used a 2.5 ID to 2.5 OD reducer and cut the slots with a hacksaw and used a dremel to grind and fit. Because I kept all the 3 pipe cover fasteners in place I can piece the original cut section back together with a 1.5 inch connector and put the original cover on if needed. I also plan to paint the tip and muffler with heat resistant paint to match the motor. Got the shorter metric screw and lock washer at Lowe's to hold the system in place. I think it looks great and it sounds much better than stock.

 

painted stock exhaust

Barbeque paint , well done ugly part.

I liked the look of black endcap with shiny rivets .

 

Inside the FJ muffler | FJ-09 Forums

It would appear that the FJ owners are ahead of us FZ owners with knowledge of modding the stock exhaust. Cut a hole or two into the third chamber and cut the inside portion of the exit pipe and you are all set. No reflash required. Maybe just block off plate.