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FMF Apex quiet inserts

65 posts · Started by warh0rn · 11 Dec 2009

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Post 1 by warh0rn,

#1
I've just fitted the FMF Apex slipons, and decided to try them first without the quiet inserts to see how loud it was. Pretty loud it turns out. So I'm going to try the quiet inserts but was curious is there are any other Apex owners out there that have tried the inserts in both directions. Is there much difference in the noise level with the inserts in one direction or the other? Any noticeable power difference in either direction? Thanks.

Dave

Post 2 by darko,

#2
That loud eh? Too loud for you or trying to be considerate to your neighbors? I am about to buy some of these myself..

Post 3 by 250lbsofsin,

#3
I still haven't checked wether my FMF Apex cans have the quiet inserts installed as I bought my SDR with them mounted...

But I can tell you they're pretty loud. I always coast into my street in neutral at night because they'll wake up the neighbours.

Post 4 by high_side,

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Post 5 by Fendt,

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Post 6 by Stratkat,

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Post 7 by crotchslider,

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Post 8 by high_side,

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Post 9 by crotchslider,

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Post 10 by darko,

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Post 11 by crotchslider,

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I just peeled my stickers right off, no damage that I'm aware of. Unless they changed the stickers?

Not sure about noise reduction as I find mine drone annoyingly when riding around for more than 200k, might get rid of them.

Post 12 by high_side,

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Post 13 by Katoom,

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[quote="high_side"]Reviving an old thread....

I put a set of these pipes on my SuperDuke tonight and holy hell are they loud. I threw in the quiet cores in and at idle there seems to not be a lot of difference. After having aftermarket pipes on my last several bikes, these are by far the loudest. If anyone has any idea how to quiet them down I would love to hear it (if I can over my bike!).]

Same deal. Ordered them with my SD I picked up last month, and thought I made huge mistake. HOWEVER, on advice of Brett at Eric's in Pasadena, got some 17 ga. stainless sheet with 5/32" holes all over it, cut to size and shape and brazed it onto the outside of the large end of the silencer cones, and inserted in the usual place just ahead of the mufflers with small end of cone into muffler. It's perfect. Wife says as I drove away, sound was much less, and lower in pitch. When riding use ear plugs, and can just hear exhaust burble over wind noise at about 60 mph; faster you go, more that wind noise starts to takes over. Still has great torque and throttle response, and seems no/insignificant power loss. The 2:1 conversions on KTM ADV bikes are known to increase torque and about break even on top end horsepower with added backpressure.

Found a piece of this ideal perforated stainless sheet at Paykel, retailers of BBQ and fireplace stuff. It's about 8"x10" and pricey at $15, but you only need about half of it. Also, all edges of cone where you braze on this screen must be cleaned up with grinder/file, so that will fit cleanly into its place in the head pipe attached to the mufflers. Also observed that this connection of 'screen' to cone is virtually unstressed. If you prefer, doing silver solder will probably hold well enough, and can be done with propane torch if you don't have gas welding setup. Problem solved.

Post 14 by crotchslider,

#14
Sorry it took so long for a response (I thought I got an email when someone responded)....

Do you mean wrap the stainless around the insert and insert it in to the tailpipe facing the muffler? I drew it all out but unfortunately the whole picture wouldn't scan. The arrow refers to placing it in to the tail pipe leading to the muffler. How long does the stainless need to be? Is there an end cap on the newly formed stainless insert that forces the flow outward through the packing?

Sorry about all of the questions but it sounds like you have solved the problem and I don't want to reinvent the wheel!
Image
Cheers,

High_Side

Post 15 by Katoom,

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Post 16 by Katoom,

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Post 17 by crotchslider,

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Post 18 by Katoom,

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Post 19 by crotchslider,

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Post 20 by high_side,

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did my first ride with the FMFs in without earplugs and my shitty AGV helmet....definite ringing afterwards

but, they get a lot of attention for looks and the sound....wouldn't change them out for anything.

I quickly browsed this thread, where do those silencers go? right after the Y pipe before the muffler? if so that is brute, my buddy's silencer goes at the end so we can pull em out pretty easily or put them back in pretty easily.

Post 21 by Katoom,

#21
O.K., here's some fuzzy pictures of mine. I used 5/32" industrial screen and welded them in as shown:
Image
Image

I inserted them as instructed and they are an improvement. The bike is still borderline obnoxious but I am considering keeping the pipes now at least. How do these look compared with the barbeque plate that you used? More restrictive or less? The bike runs better but still back fires indicating that it needs some fuel mapping. Thanks for the tip!

Post 22 by Reb,

#22
Wow! I can't believe that the pipes are still "borderline obnoxious" with your new quiet cores. Those screens seem very restrictive. I don't have them so I don't know but it seems like that would definitely do the trick.

Would there be any advantage (or disadvantage) to...

1. doing the same thing but not to the large end, to the smaller end?
2. doing both ends?

Post 23 by crotchslider,

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Post 24 by crotchslider,

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Post 25 by high_side,

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I inserted them as instructed and they are an improvement. The bike is still borderline obnoxious but I am considering keeping the pipes now at least. How do these look compared with the barbeque plate that you used? More restrictive or less? The bike runs better but still back fires indicating that it needs some fuel mapping. Thanks for the tip![/quote]

Sorry, overlooked a direct reply in my last post. First, your very welcome, and I'm glad you noticed an improvement. Bottom line, I was trying to answer the same question--keep the pipes, or take a loss an do something else. The screen put me on the side of "keep."

The BBQ screen from Paykel resembles your bottom picture, i.e., mostly holes with just narrow connections--but strangely your top picture looks like 1/8" holes. Did you photograph 2 different kids of screen, or just some weird optical distortion? Also, when my FMFs were installed initially, Scuderia West changed the bike to the Akrapovic map. I get 40 mpg on the rare occasion when I'm not riding like a hooligan, no backfiring and very smooth throttle.

Post 26 by Reb,

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Post 27 by high_side,

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Post 28 by jcarlson9,

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Post 29 by Reb,

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Post 30 by crotchslider,

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After making my drilled and welded inserts, today was my first chance for a good run.

The bike was definately quieter at idle. The modded inserts have taken the sharpness out of the exhaust note. It is still loud and still makes your chest vibrate when standing near it but does'nt hurt the ears as much.

I beleive the bike is more responsive (an increase in torque??) above 5k.
Pickup and acceleration from 120 to 160 clicks and above is impressive. A definate improvement. Wishfull thinking? Maybe, but these inserts must increase the exhaust backpressure which in turn must effect performance somehow. My seat of the pants dyno senses a noticable improvment.

All in all, a cheap and very worthwhile mod.

Post 31 by Katoom,

#31
I beleive the bike is more responsive (an increase in torque??) above 5k.
Pickup and acceleration from 120 to 160 clicks and above is impressive. A definate improvement. Wishfull thinking? Maybe, but these inserts must increase the exhaust backpressure which in turn must effect performance somehow. My seat of the pants dyno senses a noticable improvment.

All in all, a cheap and very worthwhile mod. [/quote]

You're not imagining that increase. Brett at Eric's mentioned that the straight through design of the FMFs isn't the best, since the motor actually requires a bit of back pressure in order to function efficiently. He predicted that it would produce more torque throughout the rpm range. He's the man.

Post 32 by superduke08,

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Post 33 by Katoom,

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Post 34 by superduke08,

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Post 35 by Katoom,

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Post 36 by MrZ32,

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Post 37 by superduke08,

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Post 38 by Katoom,

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Post 39 by Katoom,

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Post 40 by Fendt,

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These things are straight through so packing would help but I thnik they need more restriction. Thanksgiving got in the way so my SD wonn't go into FMF for testing until next week. Stay tuned.

Post 41 by Katoom,

#41
Finally got my bike down to FMF and they worked up some db killers as shown. Won't have time to test these until after Xmas but I'm hopeful that at least one of these sets will quiet this beast down to reasonable levels!

Image

Post 42 by crotchslider,

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Post 43 by Erwin8r,

#43
Any progress or update posts on this? I am very curious as I might pull the trigger on some FMF's...

Thanks!!

BTW--who has the best deal on the FMF's right now?

Post 44 by DGShannon,

#44
How did such an interesting, and useful, topic just die off, with no specific outcome?

Would love some of these, for my pipes. The inserts I have, are just plain open ones, from the factory. Anybody know if ones with mesh ever became available from FMF, or anyone?

Post 45 by rac,

#45
hi
i have used to 30mm washers turned upright welded onto a bolt , can turn as and when to deaden the sound , i seen this on a race car from the 1930s
simple idea..

Post 46 by Xfanman,

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Post 47 by DGShannon,

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Post 48 by speedmotorrad,

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So, still confused about whether FMF offers inserts for the Apex pipes? I emailed them directly but never received a response. Love my pipes, but they are LOUD as HELL! Anyone?

Post 49 by DGShannon,

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Post 50 by speedmotorrad,

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Mine did not come with inserts, or the dealer didn't give them to me. Hmmm.

Post 51 by Xfanman,

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Post 52 by crotchslider,

#52
The subject reawakens! What we need is input from Katoom; Katoom are you listening? The idea is that the mesh actually bounces sound waves back toward the motor, softening the sound noticeably. The mesh also adds restriction, but that's only compared to the wide-open, straight through FMF pipes--compared to factory, the system is less restrictive, better looking, and way lighter. General experience from tuners is that you have to have some back pressure in the exhaust, otherwise you lose torque.

Katoom had an in with FMF, and the different varieties of mesh he posted on Dec. 21, 2010, were to be tested by FMF on their dyno, using Katoom's ride. Also, FMF was considering a different insert for the muffler that would pinch down to some extent from the straight through design in order to have the muffler absorb more sound. Then, it's as if Katoom dropped off the planet, so no further info on either the screen arrangements or the basic internal shape of the mufflers. I'll try a PM to Katoom to see if he ever went further with FMF. Hopefully he'll post and let us know.

Post 53 by Xfanman,

#53
Well I think my exhaust is a little more "mellow" sounding if not actually quieter. I think I read someone say it seemed to take the shrillness or sharpness out of the "bark". I'd have to agree, at idle it seems little changed ( although my wife says she could tell a difference) but on the road it did seem toned down a bit, but not much.

If I can get one of my guys at work to weld some screen to the inserts I'll try that next.

Post 54 by BadBikerBob,

#54
Hello,

I bought my 2008 ktm duke 690 with the FMF apex exhaust and the previous owner made a db killer himself that cracked the exhaust because of vibrations - I really liked that FMF apex exhaust and would like to buy another one just that I cannot find one anywhere. Can you please tell me where I could buy one for my bike or where I could search or askk for it?

Thank you

Post 55 by Xfanman,

#55
took the plunge and picked up a set of FMF Apex......Damn they are pretty.....But OMG obnoxiously loud even with the quiet inserts. (Quiet, my ass! It takes them from ear shattering 747 at full takeoff power to a still disrespectful front row Metallica concert!). After several failed attempts to modify the inserts, I've found a solution that works very, very well for less than $20. Thank you Ebay...I love you!



They replace the stock inserts, and only need a minor mod to work. The outer lip on the large end needs to to be flared out like the stock insert so it will seat in the right location. I'm running the Akro slip on map with a BMC filter, and wow, the improvment is incredible! Feels like someone finally pulled the plug out of the ol' Thunder Pumpkins ass!

Post 57 by Xfanman,

#57
BadBikerBob, when you say you modified the FMF inserts before you tried these Ebay inserts, what did you do that didn't work? Also, you don't feel the insert you have now is too restrictive? I've got to quiet down my FMFs too, even with the FMF inserts it's obnoxious at times.

Thanks much ... Scott

Post 58 by BadBikerBob,

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Post 59 by crotchslider,

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Well I just ordered a pair of them. For the $16 it cost me it's easier than tacking on the drain screens to my FMF inserts or one of the other mods. If it doesn't work, not much lost but a little time and a few bucks. If it does work...should make my SDR MUCH more enjoyable and I owe the OP a beer

Post 60 by Woody80,

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Post 61 by Xfanman,

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Post 62 by ktmguy,

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Anyone here who can make a photo of the modified universal baffles ???
I got my FMF today. Not installed yet, but in Germany I will have to reduce the noise

Post 63 by BadBikerBob,

#63
Ah come on. Really no one here who can help me???
I also would need an actual link to these baffles. The posted links are out of time.
Please guyys help me. Don't want to switch to akra

Post 64 by skapan,

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Post 65 by nampus,

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Looks like the seller has sold out in our size. Here is the item number in a smaller diameter 130984710974
He is almost sold out of them too. If he is smart he will commission more.
Sonic can you take the item pics to local exhaust people and have them replicate?
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