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Installing an Exhaust Valve


EVLXX

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Aka: My Stealth mode valve.

I had an idea...

I wanted a way to be Stealthy quiet in town. Like a Cat hunting its prey, fast and sneaky… and quiet. I do NOT want to be the obnoxious asshole that runs through town waking everyone up pronouncing “Here I come!” Mainly because I leave for work at a time when most everyone else is just getting out of bed, and secondly because I live in a city with 3 different law enforcement facilities, City, County, and State Patrol stations, that I have to pass by on my commute. Yes all of them.

However, once out of town... I wanted to have the benefits of having a free flowing exhaust, More HP, less engine braking, less exhaust heat, etc., and well once out and away… who cares if I make a little noise.

So, what to do... Well first off one needs to buy a Free flowing Exhaust, I did that years ago. Then after some trial and error, I finally built myself a baffle system and installed it into the Right side Exhaust canister. Amazingly enough, this muted a lot of the "noise" of the exhaust note but left the tone, so this was a huge improvement, but still not enough. It’s still loud enough that my wife can hear me at the stop sign about ¾ of a mile away, and knows I’m on my way home, or when I’ve driven by the neighborhood to go for a short ride down a windy road. I wanted stealthy quiet (like stock) but, on demand. No… let’s rephrase that… I need Stealth mode. Let’s face it, if the wife can hear me coming from a mile away….. So can the cops. So what I need is a Valve to open and close the left side open exhaust canister. That shouldn’t be too difficult, right?

Initially I searched the internet for an exhaust valve of any kind, and what I finally decided on was an Electric Exhaust Cutout Valve. You can find them all day long on Ebay, and from what I can tell they must be popular somewhere, because there’s a lot of them available in different sizes. However, the smallest diameter one I could find in a butterfly configuration was a 2-1/4”. I wanted a butterfly valve and not a slide valve, because I was hoping to install the unit in line with the current exhaust. In other words, cut a section out of the current piping somewhere an install the Valve, hopefully where you can’t see it.

So I order a cheap 2-1/4” electric cutout valve off of Ebay, and wait for it to arrive. Once I received the Valve I tested its opening and closing rates, and holy cow is it slow. If I was going to hook up the electric switch, I was only going to do so if it can open and close in under 1 second. So right off the bat I know I’m ditching the servo motor that came with the unit, and I’ll have to figure out some way of manually operating it in the meantime. So here’s the Valve with an additional ¼” shaft coupler on it.

Picture 1post-726-0-92986200-1440855775_thumb.jpg

Now first off, this thing is huge, and is going to be impossible to hide anywhere on the bike in its current state, so I can see I’m going to be modifying it first. This means I’m going to have to make my own, much smaller mounting flanges. I have a scrap piece of 3/16” stainless steel sheeting that I planned on making the new pipe flanges out of. The only this that sucks is trying to cut thick stainless steel. Luckily for me I have a cheap plasma torch. It does a crude job, and leaves me with A Lot of grinding to do, but it’s the best option I have to get this part done in a day.

Picture 2post-726-0-92476900-1440855799_thumb.jpg

After making my hands go numb from grinder vibration, I end up with this.

Picture 3post-726-0-73981700-1440855815_thumb.jpg

Ok, I have to drill some holes and cut down the main body of the unit. Initially I had planned to do this with my woodworker band saw. However, once I looked a little closer I was reminded that I no longer had a metal cutting blade. Doah! OK, I’ll just use my trusty jig saw. Doah, one crappy blade for it as well. Well after a trip to the hardware store and some very slow cutting I end up with this.

Picture 4post-726-0-25028500-1440855829_thumb.jpg

So after a weekend of work (Saturday and Sunday) I am ready to cut the stock header and test fit it on the bike. Now I knew this was going to be no easy task, because the valve is 2.25” and the header pipe is roughly 1.9”. This means where ever I cut the pipe I’m going to have to flare the ends of the pipe, “a bunch”, in order to clear the butterfly valve and be able to weld them to the flanges I made. So after a lot of thought I cut the stock header just behind the oil pan. That should work, and it lease me a good place to route a control cable or shaft later. Oh but wait… what about the center stand?

Picture 5post-726-0-51125400-1440855838_thumb.jpg

Fuck, fuck, fuck fuck. This fucking sucks, an entire weekend of work and it won’t fit with the center stand. At this point I’m so mad I can’t see straight and just decide to start drinking.

Well time passes, and I wake up the next morning with a few thoughts, maybe I should just make my own butterfly valve and install it onside the existing header pipe. At this point I already have the header cut, so all I would need to do is make some flanges for it and go from there. Yep, that’s what I’ll do. Now to cut down, build, or buy the new butterfly valve. Well after looking at the valve that’s in the 2-1/4” unit, it’s obvious I cannot cut it down and maintain a seal around the shaft on each side of the pipe. So, I’m either going to have to make one, or buy one. Buying one sounds easier. Well after a little searching I end up purchasing a 46 mm butterfly repair valve for a Mikuni carburetor. Let’s hope it fits. In the mean time I’ll get back to work and make the flanges to bolt the header pipe back together. Here’s a couple picture of that.

Picture 6 and 7post-726-0-05591900-1440855847_thumb.jpgpost-726-0-80784500-1440855854_thumb.jpg

Well with that part done, which was a big relief, because even if the valve turns out to be a complete failure those flanges will allow me to return the bike to a stock configuration. I wait for a couple days for the valve to arrive, and its game on again. The very next Saturday morning I installed the new butterfly valve in the left side header pipe that I had cut off. The only tricky part about this was, I absolutely had to have the valve perfectly centered in the pipe, which meant that I had to hand drill the holes for the shaft in just the right spots. If I was of just a little, the valve might bind on get hung up when opening or closing. So I took a piece of tape and wrapped the pipe several times in line with where I wanted the valve to be. Then I cut the tape off, found the midpoint, and used it to mark my 2 drill points. It worked perfect. The 34mm valve was a perfect fit, in fact, it’s too perfect, and it’s too tight. So I had to sand down the sides of the butterfly plate, so that if it expanded while in operation, it should still open and close. Here’s a picture of the valve installed in the pipe.

Picture 8post-726-0-43685400-1440855860_thumb.jpg

While I’m at it and I have the Header off, I decided now would be a great time to possible help the coolant radiator out and install some header wrap. I only wanted the header wrap directly behind the radiator and nowhere else, for a couple of reasons, but I’m not going to get into that discussion right now. So here’s a picture of the Valve and the Header wrap installed.

Picture 9post-726-0-69893700-1440855873_thumb.jpg

And here’s a picture of the valves location on the bike.

Picture 10post-726-0-95140100-1440855881_thumb.jpg

As you can see in the last picture, I found a cable that I thought would work perfectly for the manual control part of the job. However, I still did not know how I was going to mount it, and keep tension on it, and make it easily accessible while riding down the road, etc. etc. Well after some thinking I decided to make my own adjustable cable holder mount. The pictures that follow should walk you through that process without explanation.

Pictures 11 thru 15post-726-0-55532400-1440855890_thumb.jpgpost-726-0-36526000-1440855898_thumb.jpgpost-726-0-58394100-1440855906_thumb.jpgpost-726-0-41280200-1440855917_thumb.jpgpost-726-0-49134100-1440855926_thumb.jpg

Here’s is a picture of the final location of the control cable knob. Does it look familiar, it should, it’s a spare XX idle adjustment cable I had lying around.

Picture 16post-726-0-90783300-1440855935_thumb.jpg

Now for the riding test results.

Closed the bike starts and idles like a purring kitten. I was actually shocked and how well it idles now. It’s one of those things that you easily forget when install an open aftermarket exhaust and are blown away with the exhaust note. Since I have an Air Fuel ratio gauge installed on my bike, I was also able to notice the fuel ratio had dropped about 0.5 when the valve is closed, and the bike seems to warm up faster. Although I haven’t run any timed comparisons. Additionally the low ends torque seems to be improved compared to the open exhaust. It’s a smoother pull, I think. Now for the cool part, with the Valve closed… it’s quiet. Like sneaky quiet. Oh…. now it’s mischievously fun to ride the bike to work in the morning. Ssssshhhh don’t tell anybody… but I might be hammering the gas leaving this traffic light, or I might be traveling at a very high rate on this connection road. LOL. Oh damn this is fun. Not only that… I can hear my Sena Bluetooth helmet speakers loud and clear. Hu… imagine that, I can hear all kinds of shit over the exhaust.

At any time I can reach down and twist the valve to the left, Open, and its play time. I also leave the valve open when I am running down the highway, because at those speeds the exhaust noise is minimal anyways, and due to the lack of engine braking etc, I get better gas mileage.

Hmmm… I wonder what I’ll come up with next.

Edited by EVLXX
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I always love your mod threads.

Nice work.

I have been reviewing your HID shield post recently. Even have my spare bulb and ballast out for a look see.

Thanks for making things that I can copy.

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30 years ago I had a device called a Deci-Foil installed on my CB900FA

Same idea but that hunk of crap was poorly made and dropped me in shit at a police decibel test set up at a time when mother-grundies were bitching about us hooligan bikers. They set the tripod up behind my bike, I closed the valve and started it and it was great until they ran a sustained 5000rpm for about 2 minutes and it went from brrrrrrrrrrrrrr to BRRRRAAAAAAAAAAAHHHHH and I got nailed for 109db noise pollution and a mandatory roadworthy test.

FUCK!

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No decible meter available... would be cool to measure it though. I downloaded a decible meter app on my phone once, but i don't think it worked very well.

It would also be cool to run some open and closed Dyno runs as well.

Eventually I would like to make it an electronically controlled valve.

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So, this valve just closes off one of the exhaust cans, forcing all exhaust thru the other can?

Edited by jon haney
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So, this valve just closes off one of the exhaust cans, forcing all exhaust thru the other can?

Correct.

Closed... it forces all the exhaust through the right side can, which I made a slightly... free-er flowing baffle system than the stock baffle system.

Open... any extra pressure goes out the left side.

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That's pretty sweet, have you used a decible meter go test out the difference?

Now I can say.... Yes.

I tested several different app decibel meters using my Galaxy S5 Active. Most of them really didn't change very much, and would max out at about 83-85 dB.

But I found One that seems to have actually given me some promising numbers. It is the "Sound Meter Pro" by Mobile Essentials. It recorded the following results @ 5200 rpms one meter directly behind the motorcycle.

Closed. 80 dB

Open. 91 dB

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My V-twin turns over 10k, good to know it only has to be tested to 2K. Regardless, the muffler is stamped with all the right legal stuff on it so there's no way it could be too loud unless it became defective somehow.

Fuckin dremel.

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Pressure... Correct.

I also think it's BS. that the guy in the video over dramatizes the harmfullness of of the levels, and it's BS that the "motorcycle" test is measured at 20". I was recently at a Railroad crossing test, and they measured the signal decibles at 10 Feet.

I'm going to have to retest this using my phone and the prescribed angles and distances above, and see what I get.

I might even put the Stock exhaust on, yes I still have it, and see what it is.

Might not be today... might take a few days, for a time slot to open up in my schedule, but I'll get there.

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OK, I just did the test. First thing was to calibrate the meter. I don't have my actual meter from work. Tested against it before with a different phone and it was always within a decible or two up to just over 100db.

So I had nothing on in the house except the fridge and my fish tanks. Both were 20 to 30 feet away. I placed phone in back bathroom on counter and let a minute pass to get a baseline. Held around 32 to 33 db. Clicked it down till it down and did this till it held around 1 to 2 db in dead silence. A car passed and the road noise 100ft away clicked up to 5db through the bathroom exhaust fan on the roof. Would pick up a mouse fart, amazing how sensitive the phone mic is.

Back outside, slight breeze and leaves moving in trees lightly stayed around 26db so within reason of scale.

Fire up bike and let idle for a little bit. Got 64db average. This is with the phone mic aimed towards exhaust at even height 20inch away and 45° angle. Bike has Leo Vince slipons, been on for 40k miles and never repacked. They are like wine, the throaty rumble just got better with time.

Now I roll the throttle to 5k and hold it for several seconds. Looks to hold around 73-74ish according to the graph.

I was expecting higher at 5k but didnt expect it to be over 100db either. Shooting my bow you get the snap of the string but that only lasts for maybe a 10th of a second. The arrow hitting the foam target is just as loud and fast.

Got some screen shots,

post-1152-0-81636400-1441472967_thumb.jp

post-1152-0-07885300-1441472990_thumb.jp

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That was the "Sound Meter Pro" app on the Galaxy S4 correct?

Nice. good job. I Like the screen shots.

edited to add: I can see that the problem is going to be in the calibration.

Hmmm... if I measure objects around the house... and compare them to general decibel level charts... my phone seems to be reading just fine with no calibration corrections.

by the way... this is cool. http://wwwn.cdc.gov/niosh-sound-vibration/Default.aspx

Edited by EVLXX
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Yep, same app that you got and using an S4 Galaxy. Have a light protection case on it but doesn't block the mic, speaker, or anything.

Having used the meters for mining use around equipment, shops, plants and in labs. We have annual noise monitoring testing for all new hires to run a baseline, then after that we will monitor for any hearing loss across a wide range of frequencies. We also get asked if we ever used power tools, (good link info also giving the power tools db readings, see many people not wear protection and use the excuse they will only be using it for a minute) ride bikes, shoot guns, been in military ect ect

I have developed slight loss after 15yrs here, plus another 5yrs or so of being cheap manual labor in the summers running everything from chainsaws to nail guns. However, I have always been the guy that wears earplugs to do yard work, run equipment, hell I even weld wearing ear plugs. Its not exactly for the loud sounds, but constant sounds like wind noise riding my motorcycle or the buzz of welding can trigger a migraine. Sad part is after 30+ years of aspirin and migraine meds its found out that they can also leave you with Tinnitus, which is a reason i try to have background noise going when I go to sleep. the ringing drives me crazy in dead silence.

Noticed the levels to be higher than expected just sitting in my living room. Yes my fish tanks make some noise but not 40 - 50db So I decided to run a baseline calibration on it in the quietest place in my house.

Was a neat test, will be exciting to see what results you come up with if you go back to the stock pipes. Here is a chart I found pertaining to noise levels

Maximum Permissible Noise Levels for Certain Motor Vehicles manufactured after January 1, 1979

Vehicle

Highway Operation, soft site,*

35 mph or less

Highway Operation, soft site, above 35 mph

Highway Operation, hard site,*

35 mph or less

Highway Operation, hard site, above 35 mph

Stationary Operation,

soft site

Stationary Operation, hard site

Motorcycles

78 dB

82 dB

80 dB

84 dB

78 dB

80 dB

Passenger Cars, less than 10,000 pounds

72 dB

79 dB

74 dB

81 dB

72 dB

74 dB

Buses

83 dB

88 dB

86 dB

90 dB

83 dB

85 dB

Vehicles more than 10,000 pounds

86 dB

90 dB

88 dB

92 dB

86 dB

88 dB

* Soft site includes surfaces covered with grass or other ground cover; hard site includes concrete, asphalt, packed dirt, and gravel surfaces.

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ok... didn't get a chance to try the stock cans... yet.

however I did a retest using the baseline adjustment, which was in the downstairs bathroom this morning, and absolutely nothing in the house running.

After this... I retested the bike using the 20" 45 degree method.

Valve closed..

Idle... 55 dB.

2K....59 dB.

3.3K..66 dB

5K.... 64 dB.

Valve open...

Idle... 59 dB.

2K.... 63 dB.

3.3K.. 66 dB.

5K .... 64 dB.

That's when I noticed the problem.... the flat line. At 66 dB the graph was a flat line, like the phones microphone or sound dampening software had kicked in, and was limiting the reading to nothing higher. In fact I tried several times to make the graph go higher and it just wouldn't. Then I noted that my correction factor was -25... which means that 66 dB is the same as 91dB ... which is the same as I measured before.

So.... this all just tells me the phone app... means nothing, it's junk. I'll have to see if I can find a true sound meter... and retest it again.

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dang, now I want to get our sound meter and try it again also. Haven't compared it to this phone, the last phone I had was a Droid X

Funny that my CRADAR app doesn't work also on my S4,

used it on my Droid X all the time for motorcycle rides and when in my tree stand hunting. in the event of a fall it will send a text message to who you want with your gps cords.

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