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Discussion Starter · #1 ·
HI,

I would like to fit a Radiant Shorty muffler to the CTX. On their site it says:

"Backpressure is decreased with our exhaust. This provides less exhaust restriction to increase horsepower at full throttle. Tuning is recommended for best performance, but is not required. Without tuning, horsepower is increased only at full throttle and torque is decreased during normal riding. If tuning is done, both horsepower and torque are increased. "

Is this really the case ? I know there are members who use no muffler at all.
 
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The catalytic converter on the CTX should give enough backpressure for the engine to run well. The only way to know for sure is to have your bike dyno tested with and without the exhaust system. Many exhaust manufacturers will claim their exhausts will increase horsepower and torque but never list any specs or results. These should be taken with a grain of salt since there is no guaranty of any increase.
 

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On a traditional carburetor or a static mapped fuel injection this would be the case tunning wise. Our power plant is constantly self tunned, so no tuning is required.

However, no matter how tunned, the effects will still apply. Backpressure always plays that trick, like a cam, you have to pick a higher or lower end power, you cant get both.

Since we have a 2 into 1 header with a catalytic converter, there is alot of back pressure still there and you will not notice a change with changing to another muffler. Even removing the muffler completly, noticing power change will be very little if any.
 

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Discussion Starter · #4 ·
Thanks fellows. I am glad to hear it. I knew you two would give me the skinny. Rebel, you took your muffler off did you not ?
 

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Discussion Starter · #5 ·
Now I just have to check the width of the header to see which Shorty to buy. I seem to recall someone on here buying one 39mm width.
 

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Discussion Starter · #6 ·
I would eventually like to try to fit the center stand. I wonder if the Shorty will clear it.
 

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Discussion Starter · #8 ·

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Please let us know how it turns out. I wouldn't mind my DCT with a little more motorcycle growl as opposed to a scooter zoom tone. Or maybe I'm just projecting because of the DCT... ;)
 

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Discussion Starter · #10 ·
ok

Please let us know how it turns out. I wouldn't mind my DCT with a little more motorcycle growl as opposed to a scooter zoom tone. Or maybe I'm just projecting because of the DCT... ;)
I certainly will. I will order it week after next as I am travelling and don't wish it to ship while I am away. Kerker has a full size muffler for the CTX, but oddly, sells it only in pairs. I am after the Shorty mostly to make it easier to get at the bike for maintenance, more than for the sound, but I am curious to see how loud it is. Unlike most, I do not find the stock muffler so ugly, and the sound is civilized. Last week I road up to visit my new infant grand daughter, and started the bike in the garage right in front of her while she was being held by her mother, and she noticed not a blink. There is something to be said for a bike that does not scare infants and pets.

Rebel has no muffler at all, so he can speak to how loud it can get. He has something on youtube where you can hear it.

@Rebel, I don't know if you live in the sticks or have neighbors, or whether it makes that much difference, decibel-wise.

In any case I will find out! I do not wish to cause any distress to neighbors. On the other hand, there are plenty of straight pipe HD beards trundling up and down, who care bugger all about neighbors or anyone else's ears, so they will get blamed for any noise I make anyway. I rather enjoy hearing the hi-rev yowl of hot sport bikes in the morning as neighbors head off to work.. It is the inner petrol-head in me I suppose. The Honda in-line 4 is the best sounding to me. There is a guy with a cb1000r with a factory-installed Yoshimura muffler on it that wins the prize. I dream about having one of those, even though mileage is worse than many automobiles, and they are ferociously impractical.

I just moved to Orlando from JAX area a few months ago, so it is a bit of a shame as I come to find out Radiant is in Orange Park, which is West JAX, FL. It would have been interesting to visit. I will get the chance in the future, one would hope.
 

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Discussion Starter · #11 ·
@LadyGadget

I finally have the Shorty fitted. It is cool looking and loud as the bejesus. In the early 80's I had a Bonneville which I had milled out to 700 and put a Hepolite race piston set in it and it had straight pipes. It could smoke any sportster in a 1/4 mile. It could smoke anything but the two stroke Kawasaki in line 4's. This sounds for all the world like that Triumph did. I have to say, I like it quite a bit. For longer trips, earplugs will be in order for sure. It certainly changes the bike's personality.

One thing I notice is that I hardly ever look at the tach anymore as I can "feel" the motor better. I know it is really "hear" the motor, but allow me poetic license. Oddly, I also always know what gear I am in, whereas before not so much. (it is a manual).

It reveals that the engine is a lot happier at 2500-3000 rmps than one would have guessed before. It could chug all day below 3000. You can just feel when the engine is "happy". It just sounds cool as all get out. I try to sneak out of the neighborhood as best as I can in the morning without to much snap and pop.

If you decide to fit it, private message me, as there are some things to get sorted out in the process. Nothing tricky, but it will save you some fuss. Paterfermente was kind enough to direct me along.

As far as power, I am sure there is little or no difference, but it does feel more powerful because you can hear the engines progression so well. I have not had it over 4500 yet to see if there would be any appreciable difference, power-wise. My guess is that it would be undetectable, except in a perceptual sense.
 

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Can you share any photo's of your exhaust mod?
 

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This is no way near as loud as straight pipes! Considering stock is about mute, it is much louder, but not to bad. Of course volume will be acceptable more or less per individual.
 

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Discussion Starter · #14 · (Edited)
There is no packing in it at all. it is just a piece of pipe. it is not a muffler. Not like the Bonneville with no cat or bends or anything, but it is loud. Not dragster loud, but loud.
 

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It's just an exhaust tip~ The catalytic converter is all that tones down the note from straight pipes.

I don't like that video. Not sure if it is the camera quality or if the exhaust was altered more or what is going on there. The exhaust just doesn't respond right in it. It doesn't respond like mine, like it has much more back pressure/restrictive in all rpms.

-Come to think of it, it may be the additional pipe clamp support is still present, the added tip and the more restricted intake may be the culprit.

Let's see some photos if you can, we love photos here!
 

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Discussion Starter · #17 · (Edited)
Ok, I will get some photos. What is the pipe clamp support R13? In my case, I just took off the muffler, and put the Shorty on the header up to the flange, and tightened the clamp on it. Are you theorizing it is not good to use the Shorty ? What do you mean by more restricted intake?

I will put the stock muffler back on straight away, if you think it is bunging something up.
 

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Your fine, you can run it the way you are. Where the muffler clamps onto the header pipe, there is an additional pipe welded into the tip to support the muffler clamp to prevent crushing the pipe out of shape. With the stock airbox, snorkle, air filter, that pipe support and added tip, it doesn't breath as easy compared to mine. Everything restrictive relates to backpressure, even just pipe, size of pipe, length of it, bends etc. How much air can you blow through a coffee straw vs. normal drink straw for an example? An engine is basicly a pump, air goes in and then out. You can only take out as much as you can bring in and vice versa. That is why just doing an exhaust job alone does about nothing performance wise. Being completley stock, air flow is pre set and tuned with the intake vs. exhaust. When you see a stock engine on a dyno, the stock intake will always be installed, the exhaust will be stock or optionly different, it doesn't matter much there.

When you match a free flowing intake along with an exhaust, it will rev faster and make more power. If you do an intake without exhaust, you will raise back pressure significantly, will increase low rpms and torque, but top end will flat out.

In the video when he lets off, rpms drop back to idle almost imediately. Also when he has mid rpms running, it sounds like it is dogging (starving/flat out) out.

Basicly your bike with the stock muffler acts the same way as with the shorty. You can just notice what is really going on there now since you can hear it.
 

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Discussion Starter · #19 · (Edited)
OHH. because yours is cut off farther up. I get it. Thanks. I am reassured. The "behavior" of everything is the same as if the muffler were still on it, I can just hear it instead of it being muffled, like pop and burble on deceleration. It happens anyway, I can just hear it now.

Does yours still have the oxygen sensor thingy.
 

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Yes, you got it.

Yes I do, you need the O2 or the system will run in limp mode. Limp mode means that it runs on a non regulated preset air/fuel mapping. It will run just good enuff to run to get somewhere to have it fixed. The O2 regulates the proper Air/Fuel mixture at all times.
 
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