Neighbor-friendly dawn patrol exhaust modification

[epnault]

@UWSkier

Agreed.  At least with turn down tips I could play around with some rubber hose attachments but I worry about them ripping the tips off the boat.

 

I also agree that the ultimate solution is the FAE system

[Hucklefin]

20 hours ago, epnault said:

Alright guys.  I finally was able to do a test with stock Prostar with just the flapper and the turned down tips.  I also included my ski buddies 205 in the test.  I only achieved 1db reduction. Essentially hardly noticeable.  I did a pass by as this is what my neighbors will hear and recorded the dbs on an app.  Pretty expensive for 1db but it looks cool on the lift now.  Ugh
 

 

 

I agree, I feel like I could barely notice it on mine.

[skibrain]

@Gale K  the manual wedge is removed… no need to make waves.  Through -35 and -38 no noticeable difference in spray or wake shape. IDK, maybe 1-2 mph slower but can’t recall for sure and we never did a back to back GPS. Boat still shows 42 WOT. 
 

Only significant difference: In a tight button-hole turn at end of the lake, there is shin-high spray off the FAE exhaust skeg as it is pushed more sideways through the water.  But that is easy to avoid by staying about 3’ inside or outside of that spot.  Surprised the first time we spun, but not an issue really. 

the exhaust is mounted via a square tube supported by the swim platform brackets. I don’t have dimension FAE sticks out behind transom, but you wouldn’t want this if you have to remove swim platform to close garage door.   I don’t know if that is the same mount system as when we did the install 10 years ago. 

[Gale K]

@skibrain thanks!  Mount system of today looks the same looking at their website.  I should have mentioned this setup would not be in the existing storage space as totally not enough space to have anything extra sticking out the back.

[epnault]

Well based on my dismal results with the MasterCraft tips my neighbor with an 09 197 ordered the FAE. He learns from my pain but his boat is really load.  Something about that model year 197.   
 

Anyways I am trying to figure out additional solutions for improvement with what I have.  Since I have the tips what do you guys think about adding some additional length with  rubber/silicone pieces like this?   Just hose clamp them in and cut to the length at the water line at plane?  Maybe cut slots in them to relieve forces on the tips?

https://www.amazon.com/dp/B09T3QTP6C/ref=sspa_mw_detail_6?psc=1&pf_rd_p=e21b1d9f-5b60-462f-8a31-00c727a694eb&pf_rd_r=D38MPF3V7WXMFYDHMGF3&pd_rd_wg=GmdMw&pd_rd_w=C4HOn&content-id=amzn1.sym.e21b1d9f-5b60-462f-8a31-00c727a694eb&pd_rd_r=4ab1fe4a-1233-4e1a-9185-ae857047335f&sp_csd=d2lkZ2V0TmFtZT1zcF9waG9uZV9kZXRhaWxfdGhlbWF0aWM&th=1

 

Thanks for the input - Eric

 

[Mastercrafter]

While I didn’t have a way to do a side-by-side comparison nor did I use a dB better, I really felt that the Malibu tips I used made the boat sound a lot less aggressive and smoothed out the exhaust note a bit. It’s hard to tell in your video but despite the similar meter reading, do you think it helped the perceived sound at all, or no? 
 

What do the MC tips you used have for baffles.. any pics? Curious how they compare. 

[ReallyGottaSki]

13 hours ago, epnault said:

Well based on my dismal results with the MasterCraft tips my neighbor with an 09 197 ordered the FAE. He learns from my pain but his boat is really load.  Something about that model year 197.   
 

Anyways I am trying to figure out additional solutions for improvement with what I have.  Since I have the tips what do you guys think about adding some additional length with  rubber/silicone pieces like this?   Just hose clamp them in and cut to the length at the water line at plane?  Maybe cut slots in them to relieve forces on the tips?

https://www.amazon.com/dp/B09T3QTP6C/ref=sspa_mw_detail_6?psc=1&pf_rd_p=e21b1d9f-5b60-462f-8a31-00c727a694eb&pf_rd_r=D38MPF3V7WXMFYDHMGF3&pd_rd_wg=GmdMw&pd_rd_w=C4HOn&content-id=amzn1.sym.e21b1d9f-5b60-462f-8a31-00c727a694eb&pd_rd_r=4ab1fe4a-1233-4e1a-9185-ae857047335f&sp_csd=d2lkZ2V0TmFtZT1zcF9waG9uZV9kZXRhaWxfdGhlbWF0aWM&th=1

 

Thanks for the input - Eric

 

Eric, like you alluded to, reinforced silicon material are what many of us have done , earlier in this thread, with very good results.   Most images have been lost

yes, in your case now with the tips,, with less total material to flex, after the main cut even with the running surface, i suggest slitting the cut edge so each segment can  flex individually and conform to the water flow off the bottom as its angle changes.

 

btw what mufflers are in the boat at the moment?

 

[epnault]

@ReallyGottaSki

thanks for the input.  I am not sure what mufflers I have.  My boat is stock 2016 ProStar with 6.2L.  I did at the ‘18 bent down tips from MasterCraft

do you kind describing the cuts you mentioned?

@Mastercrafter

i will get some pics of the internals next time I am at the lake.  
 

From the dock it sounded different and maybe less drawn out as the boat moved further away versus the stock ends.  

[epnault]

I think I need to just go all in on FAE.  Anyone interested in buying my fancy, expensive, and modified MasterCraft tips?  I paid almost $700 for the pair and can provide receipts.  I cut the through pipes off like DD did so they bolt right up.  I will send you the longer screws, tips, and gaskets on me.  $400 takes them. I just need more reduction than 1db.  I will say they do look amazing on the boat but looks isn't what I am after.  

[chrislandy]

Eric, db isn't everything(although -1db is a fair amount of energy at the levels our boats kick out), it's the frequencies too and where they are coming from.

Where are you taking the measurements from and just with a sound level meter? I'd try recording the sound and analyse the frequencies.

The soundproofing is pretty dire in the cockpit so things like decadence and adding addition linings to the dog box will help with the driver / observer experience and help to knock out some the the lower boomy sounds.

 

[epnault]

We did a shoreline pass by and drive away.  There is an improvement but…. See video.  We were recording with an app so not super accurate.  

[UWSkier]

7 hours ago, epnault said:

We did a shoreline pass by and drive away.  There is an improvement but…. See video.  We were recording with an app so not super accurate.  

Is there no way to slip a silicon boot over the tips you put on there?  The boat won't be FAE quiet, but the sound reduction of making a full 90 degree turn and releasing right above the waterline is substantial.  Would suck to go through all that work and have to dump it.

[epnault]

@UWSkier Still going to try the silicone tips but not optimistic at this point.  I was going to be at the lake this weekend but the weather is rain and high winds all weekend long.  Stayed home. 

[Sethro]

I copied @UWSkier parts list. It was a bear to get the port side Fernco reducing coupling on due to the wedge bracket. The jury is still out for me. I haven’t listened on shore, just behind the boat. I’m not sure I notice a huge difference yet. I think trick skiing might even be louder????

My next door neighbor has the same boat (2006 RLXi) so when he finally gets his out we can do a comparison from the shore. 

[Horton]

This might be an urban legend and total BS but I once heard a story of a guy who just extended his rubber exhaust hoses a few feet out the back and from inside the boat it was crazy quiet.  IDK

[UWSkier]

2 hours ago, Sethro said:

I copied @UWSkier parts list. It was a bear to get the port side Fernco reducing coupling on due to the wedge bracket. The jury is still out for me. I haven’t listened on shore, just behind the boat. I’m not sure I notice a huge difference yet. I think trick skiing might even be louder????

My next door neighbor has the same boat (2006 RLXi) so when he finally gets his out we can do a comparison from the shore. 

interesting.  For me, the difference was huge.  Pretty much exactly what you hear in that video I posted in the first page of this thread.

For a quick and easy test, loosen the smaller band clamps and remove the ABS elbows, leaving the Nibcos in place.  Stand on your dock while someone does a holeshot away from you.  Then repeat with them in place.  That or do two ski rides back to back.

[Sethro]

4 minutes ago, UWSkier said:

interesting.  For me, the difference was huge.  Pretty much exactly what you hear in that video I posted in the first page of this thread.

For a quick and easy test, loosen the smaller band clamps and remove the ABS elbows, leaving the Nibcos in place.  Stand on your dock while someone does a holeshot away from you.  Then repeat with them in place.  That or do two ski rides back to back.

I plan to do just that.  I'll see if I can come up with a decibel meter as well.

[epnault]

@Sethro @UWSkier

Thanks guys.  How did you determine the vertical length (downward) of the tubes?  Straight edge off the bottom of the hull?

[UWSkier]

19 minutes ago, epnault said:

@Sethro @UWSkier

Thanks guys.  How did you determine the vertical length (downward) of the tubes?  Straight edge off the bottom of the hull?

The transom has a hook on it so it's not an exact science, but yeah, pretty much.  That and the eye test once underway to see if there was a bunch of spray being generated.  Minimal spray is fine.  No more than a micro-tuner creates... :)

 

[epnault]

@Mastercrafter

Here is the pic of the internals on the turn down MC tips. 
 

This is what I will be testing tonight.