Inside the FJ muffler

[rinconmark]

http://www.ty-parker.com/newbike/lewis5.jpg
Is that the picture the final result before putting lid back on ?

[rinconmark]

Hi Papac2000 ,
I would like to do your way that received 5 hp on the dyno . Can you give the exact specs ? keep  reading this post with so many opinions its getting a little confusing . lol
Thanks
Mark

[ULEWZ]

http://www.ty-parker.com/newbike/lewis5.jpg Is that the picture the final result before putting lid back on ?

Yes. No need to weld all the way around the new pipe in new hole. My pipe did not have the exhaust tip cut off and a new 2" tip welded on, just the S-tube cut, a new hole cut, and a section of the S-tune cut and welded into the new hole. Then the section of the S-pipe that remained in the exhaust tip was cut. Is this way as good as putting on a new 2" tip? Well, I was actually going to have Ty finish the job and cut my stock tip off and put in a 2" section, but sadly, that is no longer possible. Why, because it results in a subtle, but lower sound. I am actually fine the way it currently is, but.... 
Everything you need to do is in the pages and pages of posts, so read up and give it a shot.
 

[xlxr]

http://www.burnsstainless.com/sm-scrubble.aspx
 
This is the best packing material I have found, not cheap, but lasts a lot longer. It uses a type of stainless steel that is meant to withstand high temps in exhaust. The exhaust tone is not as deep as all fiberglass packing. It needs perforated pipe with smaller sized holes to keep individual strands from blowing through the holes.
 
 Fiberglass will eventually fall apart and get louder.  Some types of kitchen stainless steel scrubbies will burn up and break apart into small pieces that clump together and partially clog holes in the perforated tube.
 
http://steelwooldirect.com/muffler-packing/
Here is another link to good packing material.
 
My concern (meant to be constructive criticism for others to improve design) with the mod as done by Rodan on page 11, is that eventually the fiberglass packing closer to the pipe will burn out first and need repacking in (guessing) 25K miles.   This design should perform very close to a typical glass pack / straight through muffler, fairly loud with minimal back pressure that typically shifts the power band higher in the rpm range, and may loose low end torque.  It may also require ECU remap.    I will have to go back and see if he posted a ride report, I don't remember reading it.
 
I do not have any experience with packing so deep from the perforated pipe to the far side wall of the muffler.  I am only guessing again, but it may be cheaper and lighter to weld in a baffle closer to the perforated pipe so that you do not have to fill the entire muffler volume with packing.   I also am not sure how that would change the sound or performance.
 
My comments are based on experience with other bikes, other mufflers.  I have no intention of cutting open my FJ exhaust (for now any way).
 
 
 

[adjuster]

Have been busy this winter, and have not had time to mess with the bike, or even try and put the GPR exhaust on the FJ09 that was designed for the FZ09.
 
And I have not had time obviously to try the "Easy" minimal cut and weld mod to the stock pipe, but the more I run this around in my head, the less I'm worried about weight, and the more I want a skid plate that's rugged, cheap and easy to install. Even the new oil pan with the forward facing oil drain plug needs a skid plate if the FJ is to be used in any sort of way off road, and folks have hit high speed bumps in parking lots and curbs just using the bike around town. *Resulting in cracked oil pans.*
 
Low profile oil plug from Mazda, file down the "fin" and a simple stainless skid plate that bolts to the stock exhaust "scrotum" or can part would be nice looking, low profile, and for anyone with a stock bike, pretty easy to install too either with self tapping button head screws or if you can weld, drill a few holes, and weld in a few nuts and use button head bolts.
 
I used to fabricate all sorts of farm equipment, and belting transfer boom systems, so if I can get this right, it would be a great product or upgrade and the price would be pretty reasonable. The skid plate could be made from either stainless or aluminum. The aluminum might radiate heat away from the exhaust pretty well too, not that there is a heating or overheating problem with the stock exhaust, but on hot days, anything to reduce the amount of heat coming up from the bike at stoplights would be nice. There is no fix for the stock cat, it's just hot, and that's there if you keep the stock exhust, but it's in a can that radiates the heat away, and the more you can remove while moving, the less you have to deal with when stopped. (All the non-cat aftermarket systems don't have this issue, thus run cooler all the time, moving or stopped.)
 
One thing about aluminum is the mounting holes can be countersunk, so the bolts would be flush when tight, making the skid plate less likely to catch should you scrape over something.
 
Ok, back to the mod ideas:
 
Here is what I'm going to do with the stock exhaust.
 
Cut off at the larger weld of the "bulb" that the stock tail pipe exits out of. The S pipe is attached to the exhaust tip inside as pointed out, and when cut, releases the S pipe.
 
The entire bulb, and end tip will then come off, leaving the S pipe end sticking out of a larger hole into the rear chamber.
 
There should be room around the sides of the S pipe and case opening cut at the bulb to use a die grinder and pineapple to further remove the "case upper and lower" that makes the "hole" for the exhaust to get out.
 
When that's done, there should be room to see down to the "X" stamped into the wall that the Cat dumps against, and that the transfer pipes pass through from chamber to chamber.
 
using an extension and 1/2" drill bit, drill a series of holes along the "X" in a sideways "V" facing the drill bit, so they should be easy to drill. Figure about 10 holes total, in a line going up one side of the "X" and then up the other arm. In theory, this would flow about as much as a 2.5 inch ID hole, but in reality, not so much, since they don't have pipes, are just holes, and fluids tend to not like sharp edges like this, but hey, it's just a test.
 
Put it back on the bike like this, no tip yet, and check for sound, and power via butt dyno. LOL
 
If I like it, weld the new exhaust tip up to the existing lower bracket, add the one upper bolt for the stock trim piece. (If you do this first, and then cut the pipe to fit against the case seam, and leave the lowers loose at this point, it's going to make locating the upper bolt easy, and perfect with no need to measure, you use the trim part to get the tip fitted to the case, not the other way around.)
 
Tack check for fit, and sound again now with the tip in place.
 
The final result will have the "S" pipe intact, and the larger exhaust tip around it with gas flowing out, should scavenge the middle and front chambers for the lowest flow restriction possible, but still maintain the harmonic design of the stock setup.
 
It will be louder, and will flow more, but the "tune" of the wave damping might not be disturbed as much this way. Resonance, tone and flow were all things Yamaha clearly spent some time on with the exhaust, the open systems are only worth a few HP on top, and as noted, often lose the lower torque that this engine is so fun with. Even Akrapovic revised their design, with the longer looped carbon can system to try and get the most out of an aftermarket system, as their version is either too loud, or really does not give that much of an improvement in performance to justify the cost for those of us with limited funds. (Or are limited funds, and a cheap bastard like me.
 
So, to recap, this results in only one large weld, around the "bulge to upper and lower scrotum" point, a new larger tip, perhaps as much as 3" in ID.
I will have to trim the outer end cap, to fit the larger ID tip, but that's pretty easy with a die grinder on that thin material. Of course crush the tip to oval it out, and slash cut the tip for style.
 
One more thing:
The rider who made this possible, and helped us all out so very much, RIP.
You are missed.

[grrb]

Im not sure how Ty uploads his photos, but all of them are no longer visible, which renders this thread useless... This happens on many forums, its sad because this threads are not available to people who come after...I think its because some people upload their images to third part websites to then link them to their threads, and later they erase them from this sites and consequently destroy all their posts on the forum.. instead of simply uploading directly to the forum... I dont know what they are doing wrong, other people seem to do it right, its just sad, people should learn how to post images so threads can be saved for posterity

[DavidS]

Im not sure how Ty uploads his photos, but all of them are no longer visible, which renders this thread useless... This happens on many forums, its sad because this threads are not available to people who come after...I think its because some people upload their images to third part websites to then link them to their threads, and later they erase them from this sites and consequently destroy all their posts on the forum.. instead of simply uploading directly to the forum... I dont know what they are doing wrong, other people seem to do it right, its just sad, people should learn how to post images so threads can be saved for posterity

I thought that unless you were a premium member, you couldn't just upload images to the site. You have to use some other way to host the images like photobucket

[adjuster]

I think in this case, the owner of the images passed away folks.
 
 

[caferacer]

Modded the stock exhaust on my 2016 FJ-09 this weekend following the directions already provided so far in this excellent thread! Highlights:
• Removed and re-installed without removing the center stand—key to this is to un-screw the radiator hoses (two screws, takes 2 mins) as pictured below. This frees up the manifold for easier maneuvering.
• Opened chamber and removed the “s-curve” pipe with a 4” cut-off tool
• Added extra hole from the cat chamber into the rear chamber with a 1 ½” hole saw
• Outlet pipe kept stock, ECU stock
• Got a friend to weld it back up
Very happy with the mod, it’s a much deeper tone and overall a little louder, but not too much to make it obnoxious. Feels like it removes some of the jerkiness a little too in A and STD modes. No pop on decel, but does give a nice rumble that wasn’t there before.
Time: 3-4 hours
Cost: If you have the tools and can weld, $0

 

[bugsplatered]

The Blupurple wheels are cool.

[caferacer]

The Blupurple wheels are cool.

They work as long as you don't like rim tape, since there's no possible combination of rim tape options that looks good on blurple.

[papac2000]

Modded the stock exhaust on my 2016 FJ-09 this weekend following the directions already provided so far in this excellent thread! Highlights: • Removed and re-installed without removing the center stand—key to this is to un-screw the radiator hoses (two screws, takes 2 mins) as pictured below. This frees up the manifold for easier maneuvering.
• Opened chamber and removed the “s-curve” pipe with a 4” cut-off tool
• Added extra hole from the cat chamber into the rear chamber with a 1 ½” hole saw
• Outlet pipe kept stock, ECU stock
• Got a friend to weld it back up
Very happy with the mod, it’s a much deeper tone and overall a little louder, but not too much to make it obnoxious. Feels like it removes some of the jerkiness a little too in A and STD modes. No pop on decel, but does give a nice rumble that wasn’t there before.
Time: 3-4 hours
Cost: If you have the tools and can weld, $0
 
 
Great job @caferacer! After 9000km I still grin and am glad I did mine.

[hornetmike]

Well, today I swapped out the mufflers. And the first attempt is a bust. Those of you who have been following for a while will remember that I sourced an FZ-09 exhaust for this project, making some assumptions that it would be identical to the FJ-09 piece, with the exception of the outlet and outlet garnish. Well, that assumption was wrong. The brackets on top of the muffler, while identical on both mufflers, are around 1/2" further to the rear on the FJ version. So it wouldn't bolt up to the chassis. 
Here's the two for comparison:
 

 
I also goofed on the outlet, and it's not positioned correctly. Next step is to move the brackets rearward, fix the outlet, and try again...
 
Oh, FYI, the centerstand needs to come off to remove the stock muffler. I thought I could get away with not taking it off, but learned differently.

It must be the welding, as the 2 are identical except for the brackets for the cowl. I have a stock FZ system on my Tracer,  fits perfectly (I have now sourced a stock Tracer system (£50!!!!) so the FZ muffler will be sliced and diced; do you think that I could avoid alignment problems with welding by leaving the cut only on 3 out of 4 sides and bending the top clear, or is the steel too thick? 

[caferacer]

I tried the same thing, although only opened the rear of the can, not the whole system.
 
Steel is not too thick and it bends easily. However, it is lined with another layer of perforated steel though, so when you bend it back the two pieces have distorted so that it mis-aligns the surfaces.

[duhs10]

@papac2000 when you ran the FJ on the dyno after your version 2 mod, was the ECU tuned at all, or was that running the stock ECU?
 
Sorry if you already answered that, I've been reading through this thread and I'm sure I overlooked some details.