Water Injecting at Stinger to Reduce Noise....

[Samuel Hagan JR]

Thanks for all the input guys! I'll let you know what I find out.

Samuel, not sure where I'm gonna put the fitting yet on my CMB Quiet pipe. Somewhere in the last muffler chamber I suppose. Seems to be 2 muffler chambers on these pipes. I have to look at it further with a flash light shining inside....

Kool. Let me know what you do. I'll start on mine Wednesday.

 

[Samuel Hagan JR]

Thanks for all the input guys! I'll let you know what I find out.

Samuel, not sure where I'm gonna put the fitting yet on my CMB Quiet pipe. Somewhere in the last muffler chamber I suppose. Seems to be 2 muffler chambers on these pipes. I have to look at it further with a flash light shining inside....

Kool. Let me know what you do. I'll start on mine Wednesday.

 

[Samuel Hagan JR]

Well it's Wednesday and the pipe won't fit in my boat lol. It looks like its for a 11cc. So I won't be doing any muffled trials anytime soon.

 

[Blackout]

Well it's Wednesday and the pipe won't fit in my boat lol. It looks like its for a 11cc. So I won't be doing any muffled trials anytime soon.

My .45 CMB Quiet pipe has a larger max diameter than my NR muffled pipe has, but the divergent cone length is the same. The inlet and stinger are the same. It's a bigger pipe, but will fit on my rigger no problem. I'll let you know how it goes.

 

[Samuel Hagan JR]

Well it's Wednesday and the pipe won't fit in my boat lol. It looks like its for a 11cc. So I won't be doing any muffled trials anytime soon.

My .45 CMB Quiet pipe has a larger max diameter than my NR muffled pipe has, but the divergent cone length is the same. The inlet and stinger are the same. It's a bigger pipe, but will fit on my rigger no problem. I'll let you know how it goes.

My Sport 40 is super thin. The only other way to use it would be to cut a huge hole in my cowling. I don't want that unless I absolutely have to.

 

[Blackout]

My 45 rigger with CMB Quiet pipe and water injection ran between 71 and 74 dbA today. But, the wind and air was in our favor. Shows you the problem with using db meters. Everyone was roughly 3-5 db under their norm. More testing will confirm. I forgot to pull the water injection to check the difference.

 

[Kez]

My 45 rigger with CMB Quiet pipe and water injection ran between 71 and 74 dbA today. But, the wind and air was in our favor. Shows you the problem with using db meters. Everyone was roughly 3-5 db under their norm. More testing will confirm. I forgot to pull the water injection to check the difference.

Without looking at the dB meter, can you tell a difference in the sound level when the engine was started on the bench (no wafer injection) and when the boat was placed in the water (water flowing into the muffler}? I am curious to know how much water injection will help. Going to try my after muffler with water injection.

 

[Tim Kish]

My 45 rigger with CMB Quiet pipe and water injection ran between 71 and 74 dbA today. But, the wind and air was in our favor. Shows you the problem with using db meters. Everyone was roughly 3-5 db under their norm. More testing will confirm. I forgot to pull the water injection to check the difference.

How did it perform compared to your old setup ?

Tim K

 

[Blackout]

My 45 rigger with CMB Quiet pipe and water injection ran between 71 and 74 dbA today. But, the wind and air was in our favor. Shows you the problem with using db meters. Everyone was roughly 3-5 db under their norm. More testing will confirm. I forgot to pull the water injection to check the difference.

How did it perform compared to your old setup ?

Tim K

Hard to say as I didn't have a lot of time on the old setup, but it seemed about the same. Because of the 180 degree header on the NR, I had to run the CMB pipe about 3/4" longer. The CMB has a 1.5" band, my old NR pipe has no band. I have to play with some bigger props now. Pipe length measured at the middle of the band is 10 3/8". I know you like longer pipe lengths, I think I'm now at what you had suggested earlier. This is as short as I can go, so I will just leave it and tune with props. I'm running the stock 1460 I bought from you this early spring.

 

[Tim Kish]

My 45 rigger with CMB Quiet pipe and water injection ran between 71 and 74 dbA today. But, the wind and air was in our favor. Shows you the problem with using db meters. Everyone was roughly 3-5 db under their norm. More testing will confirm. I forgot to pull the water injection to check the difference.

How did it perform compared to your old setup ?

Tim K

Hard to say as I didn't have a lot of time on the old setup, but it seemed about the same. Because of the 180 degree header on the NR, I had to run the CMB pipe about 3/4" longer. The CMB has a 1.5" band, my old NR pipe has no band. I have to play with some bigger props now. Pipe length measured at the middle of the band is 10 3/8". I know you like longer pipe lengths, I think I'm now at what you had suggested earlier. This is as short as I can go, so I will just leave it and tune with props. I'm running the stock 1460 I bought from you this early spring.

1462 cupped has worked very well for many years Craig , everyone has their opinion but for heat racing its my favourite still.

Keep up the testing. B)

Tim K