DanWill
New Member
Must have missed that on the option sheet. Darn, I knew something was off.. :::::
How about... NO MUFFLER at all! Anyone? Anyone? Anyone?
- Thread starter TCUguy
- Start date
HDRIDR
New Member
HDRIDR
New Member
Nt everyone will like n we knw dat....its my bike and will do with it as i please as long as it makes me happy. I would like to take a vid while on a ride so you can hear it but have to borrow ma buddies go pro for dat.
HDRIDR
New Member
Let me knw if da link works.
JDE
New Member
- Joined
- Aug 18, 2012
- Messages
- 1,463
- Reaction score
- 3
- Points
- 0
- Location
- Central Valley, California
Cheers to that! Don't let the haters get you down! There are still some open minded people here, who are curious of how these mods work out for you.
HDRIDR
New Member
Tnks JDE ... Well ma nc out da.dealer was averaging 63 n some change mpg. Broke da motor in n was givn me 64 n some change. I den drilled out da exhaust and went up too about 67 if i remember rite all ma numbers.were drivn same speed same ride using 91 octane fuel. Den for shits n giggles tried 87 octane n somehow bumped it up too 74n some change....I wonder how it will do with da latest mod... Besides it soundn nice too me n lookn better.with out that big o can on the side it wuld be great too squeeze a few more miles of it.
ray
New Member
How to explain scientifically that having a more free flowing exhaust improves fuel economy?
CMGuy
New Member
Yep, there sure is sound ahead of the muffler. Yep, the speed of sound is much faster than an NCX will ever be. The point of a muffler is to break up the shock waves coming out of the engine (traveling through that pipe between the engine and muffler) so that when the exhaust flow mixes with ambient - after the end of, in our case, the muffler - and the pressure waves travel to one's ear there is not the large delta p we would perceive as a loud sound or, in my case, without a muffler, loud noise. (Noise = unwanted sound.)
TCUguy
New Member
Having a more free flowing exhaust reduces frictional losses. Although, the highest loss comes at the butterfly valve on the intake.
However, if we remove losses at the exhaust, it would mean the bike has more power/torque/better torque curve. In order to havest this for fuel efficiency, we would have to drop a tooth or two on the rear sprocket to essentially have the bike create the same amount of power as before at a lower RPM < THIS is where better fuel efficiency would come in. Otherwise, you are just getting more power at the same RPM's and thus actually might be utilizing more fuel IF the ECU compensates for the higher flow rate.
Correct me if I'm wrong, but you would loose some torque with a open exhaust. No to mention you may very well be running very lean. The NC runs lean from the factory already.
Would it be worth burning a hole in a piston to you? I'll sit back and watch!
Would it be worth burning a hole in a piston to you? I'll sit back and watch!
TCUguy
New Member
Yep your right, unless you replaced the muffler with an equally as long straight pipe, you would loose torque down low BUT gain the midrange and higher. In my opinion, this bike needs a stronger mid and above, it has gobs of torque down low, so I am willingly happy to change the torque curve a bit.
As to any lean conditions, the ECU should compensate for such a minor change (in the grand scheme of how engines work) and should keep the same "leanness" as before, without going any further lean. God bless FI bikes.
But lets just pretend that you open up the exhaust, and remove all air filters. Yes, it might be leaner, but unless you drive your bike like a sportbike (which this is certainly not! lol) there should be no chance of detonation at all - sure there are exceptions, like if you live in the sahara desert where temps reach 120F (or you know, Texas), but thats not the case for the majority.
bigjeff
Site Supporter
nc700x with no exhaust @ 3:10
Danmoto Exhaust @ NC700x (model: JISU Silver) - Fitting & sound and with no exaust, too! - YouTube
Danmoto Exhaust @ NC700x (model: JISU Silver) - Fitting & sound and with no exaust, too! - YouTube
Last edited:
Loved the video! Thanks..
That guy is hilarious.
t3hGone
New Member
I just did a similar video but no actual riding for lack of a riding camera. I installed a GPR Deeptone last weekend and was just curious what it would sound like. It's not a bad sound without the exhaust on, however, I would be concerned with the cat being able to restrict the back pressure during extended application. Having a longer exhaust pipe would definitely assist in that. I love my GPR too much already as it has helped me several times during my commute through Ann Arbor. One instance being a guy turning his head one extra time to look at me while he was trying to make a left turn out of his driveway only after I revved up to 3.5K for a moment. I can share my videos once I return home to my desktop.
bigjeff
Site Supporter
That engine soulds fantastic on a straight pipe does it not. AND - not real loud.
Last edited:
gregsfc
New Member
Sorry to bring up this old thread, but I'm coming over from the CTX700 forum to get some more opinions about running without a muffler.
I've got the CTX700 faired model with manual transmission and brakes. Two owners over on that forum have reported taking off their mufflers and just running their bikes straight (not removing the CAT) but only removing the muffler and simply putting some kind of tip on the end, which shortens the total exhaust length by the same approx. length. We've basically got roughly the same system as is on the NC700X. Both of those owners state that the muffler does nothing but dampen sound and does not provide back pressure or affect performance whatsoever. When I try to confirm whether or not these owners are correct in their physics assumptions, I can't. I get conflicting information from different sources.
My dilemma...Once again, I find myself wanting something and having different motivations for doing something than any other rider than I can find out about. I'm always looking for solutions to functional or practical problems and when I research solutions I mostly find folks biased by what they want others to think about them when they see them on their bikes or with their riding gear on and no information about real transportation-related issues, which is the reason I ride.
Two things I don't like about the muffler is its size and it's color. The CTX is basically blacked out except for the muffler, and the stainless monstrosity really detracts from the appearance of the CTX700. The second thing is a bigger issue: If the muffler were replaced by a smaller and/or shorter straight pipe, then I could keep it clean underneath much more easily; I could reduce the total weight of the bike and reduce it even more because I would remove and store the pillion foot pegs and give the bike a more sleek and thinner look for possibly better mpg and simplify my daily riding life in dealing with the mess issues of a chain-driven bike. I'm all about mpg and durability; keeping things simple; protecting the warranty; and not much more. I have always wanted the bike to be a little louder, because on the highway, I can't hear or feel the engine vibration, because there is no vibration, and can't tell whether I'm turning 2,000 RPM or 4,500 RPM and so sometimes shifting and knowing what gear I'm in when in traffic; when I can't look down at the gauge; makes it difficult to ride smoothly.
Recently I removed my muffler and painted it black with plasticote, which is reversible. Now the bike looks great; like it should have looked all along, but when I had the muffler off, I test rode it. It seemed too loud at first just idling in my shed, but when I took it for a test ride and rode around leisurely like I always do (keeping the RPM at or about no more than 4,000) it really wasn't that loud or annoying. It sounded surprisingly good. Not like a rice burner. I asked my wife, and she said that it wasn't loud once I got underway, especially when I was just easing in and out of the neighborhood. I could shift much more smoothly, because I could now hear the engine. As a secondary benefit, I think that it sounds fantastic; much better and smoother sounding than I expected and no extra noise when engine breaking, which I found surprising. There could have been just a little bit of backfiring but not much; it was still very smooth sounding.
So here is the deal...I want to do nothing that would shorten engine life; make the engine run hotter; or blow a piston, but everything being equal, if removing the muffler has no negatives besides being illegal (which, by the way, is not an enforced citation where I live, nor is it a nuisance the way I ride and where I ride in a rural area, because this bike, even w/o the muffler; if ridden leisurely; is not nearly as loud as the other bastards running around my neighborhood in their modified pickups and straight-pipe bikes); I would definitely do away with the muffler, add a straight pipe if necessary and much more easily keep my bike cleaned up underneath and enjoy an easier way to shift and ride than with the too quite muffler.
I've read where the length of the pipe is important, so if it is okay to run without this muffler, does the muffler need to be replaced by a near-equal length straight pipe?
If it is okay from a functional / maintenance issue to run w/o the muffler but I do need a length of pipe, what to use for a pipe and connection to the current pipe end? Can a muffler shop handle something like this?
Do I need a short baffle added to help with some more back pressure or are the CTX700 forum members correct in assuming that this muffler adds no back pressure? I could not tell a difference riding w/o the muffler, but due to the sound, my perception of performance could be wrong.
Or do I just need to keep it stock and deal with the cleaning and lack of noise issues that I've got, even though I prefer the sound and the functionality of not having that 3.5" muffler bolted on the pipe? With the black muffler, at least it looks better to me now, even if the other issues have not been solved.
Last edited:
StratTuner
Site Supporter
Mr. OP, I'd be interested to hear your review after you remove the muffler... if I could still "hear" your review. (smile)
Honestly, there are some who would like a louder/deeper sound. Some say for safety reasons, some just to have a B.A. bike.
It's a matter of taste, but the NC is a great project bike and can be tweaked to be more like what you want.
Post pictures and we could all learn something about how the exhaust system works!
- Joined
- May 16, 2012
- Messages
- 5,265
- Reaction score
- 7
- Points
- 0
- Location
- Vancouver BC Canada
The liking of a sound is subjective; the loudness of a sound is not. A decibel is a decibel, so to speak. There are certain tones, volumes, pitches, frequencies that are better or lesser tolerated by the average person.
Nails on a blackboard, styrofoam or balloon squeaking etc., drives most people into a frenzy of ear covering and running away grimacing, lol.
One of my favourite motorcycle engine sounds, is either a 180* crank V4 gear driven cam pre VTec Interceptor with carbon fibre muffler/s, or a sporty VTwin like an RC51, TL1000, (most) Ducatis, Moto Guzzis, etc., with same type aftermarket mufflers.
A 270* crank Parallel twin like our NC with nice muffler/s or a Yamaha Super Tenere, etc., is a very close mimic to a sporty 90* VTwin, so I am really happy with my bike's sound.
So. Having set the stage, I am baffled (hahahahaha) how someone can, in clear conscience, run a straight pipe on one of these things, and say it isn't at all loud. I'm not condemming, or judging, or trying to insult, argue or whatever else can be misconstrued from my opinion.
With my DanMoto carbon jobbie, it's essentially a straight through pipe, with a token amount of sound deadening designed into it, and that's being generous. Without the baffle it was loud as all hell to me, to the point of "I can't ride this!"
With the baffle, which is pretty constricting looking at it, it's much better, but still quite a bit cringe worthy depending on throttle application. I have to make super sure I'm in too a high gear and no throttle, if I'm within sight of a cop. I pray I never pull up beside one on my right with his window down.
I *love* the sound, and I find it too loud. I can imagine how others who dislike the sound, (let alone non motorcyclists who *hate* the sound), get upset with having an irritant continually bombard their senses.
I'm not really trying to make some grand point here, and most of it's Captain Obvious, but I can see how people can fool themselves or talk themselves into believing what they say is true and justify their actions, solely based on how much they perceive their own likes and dislikes.
If I was Emporer for a day, I would want to instantly banish all Harley and Harley clone non-sporty VTwin non-mufflered bikes. I can't put into words how much I hate that blattt blattt blattt popping obnoxious crackly ear bleeding racket.
See how subjective sound can be? An RC51 with carbon Sato's = Bliss, A Sportster with shotguns = dumped in a crusher with extreme prejudice.
...but I quite like the sound of a stock mufflered Harley. I love the sound of Cop bikes, how sick is that, lol?
I find my own views ironic, hypocritical, and completely untenable arguements to justify, so I would have to decline my World Control powers, and pass the sceptor to someone else a lot more worthy, hee hee
I don't think absense of a muffler or a straight pipe of any length would physically harm your bike, and I'm not qualified to answer if any particular length substitute would be of any benefit or detraction performance-wise. I'm sure there is more to the design than 99% of us actually want to admit.
Unless you've got an arm's long list of engineering degrees and peer reviewed qualifications relating to this field, I think all the speculation is placebo effect stabbing in the dark, IMHO.
PS I love "riceburner" sounding bikes. I could listen to those all day. Unmuffled NCX's? Meh, not so much.
Nails on a blackboard, styrofoam or balloon squeaking etc., drives most people into a frenzy of ear covering and running away grimacing, lol.
One of my favourite motorcycle engine sounds, is either a 180* crank V4 gear driven cam pre VTec Interceptor with carbon fibre muffler/s, or a sporty VTwin like an RC51, TL1000, (most) Ducatis, Moto Guzzis, etc., with same type aftermarket mufflers.
A 270* crank Parallel twin like our NC with nice muffler/s or a Yamaha Super Tenere, etc., is a very close mimic to a sporty 90* VTwin, so I am really happy with my bike's sound.
So. Having set the stage, I am baffled (hahahahaha) how someone can, in clear conscience, run a straight pipe on one of these things, and say it isn't at all loud. I'm not condemming, or judging, or trying to insult, argue or whatever else can be misconstrued from my opinion.
With my DanMoto carbon jobbie, it's essentially a straight through pipe, with a token amount of sound deadening designed into it, and that's being generous. Without the baffle it was loud as all hell to me, to the point of "I can't ride this!"
With the baffle, which is pretty constricting looking at it, it's much better, but still quite a bit cringe worthy depending on throttle application. I have to make super sure I'm in too a high gear and no throttle, if I'm within sight of a cop. I pray I never pull up beside one on my right with his window down.
I *love* the sound, and I find it too loud. I can imagine how others who dislike the sound, (let alone non motorcyclists who *hate* the sound), get upset with having an irritant continually bombard their senses.
I'm not really trying to make some grand point here, and most of it's Captain Obvious, but I can see how people can fool themselves or talk themselves into believing what they say is true and justify their actions, solely based on how much they perceive their own likes and dislikes.
If I was Emporer for a day, I would want to instantly banish all Harley and Harley clone non-sporty VTwin non-mufflered bikes. I can't put into words how much I hate that blattt blattt blattt popping obnoxious crackly ear bleeding racket.
See how subjective sound can be? An RC51 with carbon Sato's = Bliss, A Sportster with shotguns = dumped in a crusher with extreme prejudice.
...but I quite like the sound of a stock mufflered Harley. I love the sound of Cop bikes, how sick is that, lol?
I find my own views ironic, hypocritical, and completely untenable arguements to justify, so I would have to decline my World Control powers, and pass the sceptor to someone else a lot more worthy, hee hee
I don't think absense of a muffler or a straight pipe of any length would physically harm your bike, and I'm not qualified to answer if any particular length substitute would be of any benefit or detraction performance-wise. I'm sure there is more to the design than 99% of us actually want to admit.
Unless you've got an arm's long list of engineering degrees and peer reviewed qualifications relating to this field, I think all the speculation is placebo effect stabbing in the dark, IMHO.
PS I love "riceburner" sounding bikes. I could listen to those all day. Unmuffled NCX's? Meh, not so much.
bamamate
Elite Member
- Joined
- Oct 5, 2012
- Messages
- 2,360
- Reaction score
- 52
- Points
- 48
- Location
- Allford, FL/Dothan, AL
Lots of opinions on this so here is mine……..
With the NC or CTX there is no significant performance advantage to removing or changing the muffler. The stock muffler probably does add some back pressure but the cat is the main restriction in the exhaust. There is plenty of pipe length after the cat to where the muffler connects though generally it is recommended that the exhaust exists behind all riders so you don’t get exhaust gasses directly piped to the rider. That is actually more important in a cager than a motorcycle but is still safest to have the exhaust exit behind. A muffler shop should be able to fashion a nice pipe if you want one.
With the NC or CTX there is no significant performance advantage to removing or changing the muffler. The stock muffler probably does add some back pressure but the cat is the main restriction in the exhaust. There is plenty of pipe length after the cat to where the muffler connects though generally it is recommended that the exhaust exists behind all riders so you don’t get exhaust gasses directly piped to the rider. That is actually more important in a cager than a motorcycle but is still safest to have the exhaust exit behind. A muffler shop should be able to fashion a nice pipe if you want one.
