272 silent thunder baffle loose, need advise
 

I noticed last fall that my 272 silent thunder had a loose/rattling baffle inside.

any tricks to taking the platform off and "fixing" the baffle. it is a little annoying trolling listening to that "buzz"

while i'm at it, i think I will drill out the baffles for increased noise pollution.:D

If you are intending on "drilling out" the baffles you will need to remove the chrome exhaust tip anyway. Then just fiberglass the baffle in place with some quality layup. I have one 2.5" hole drilled in the middle of each. I wish I had done two holes on each side that size for a little more rumble.

You will be please with the results.:D

Trevor

If you remove the whole swim platform, is it totally open from the inside, or only a hole for the exhaust pipe to enter. wondering if it is worth the trouble removing, to gain more acess to all sides of the baffle to re glass it in place.


any one?

Wild H, did you epoxy the exposed glass after drilling to seal it up due to the exhaust water? is there a need

I didn't bother. It's been 3 years and it is just as it was then. Solid. I was checking it out in Florida while sipping of a few cold ones at the sand bar in front of the Tiki Bar in Islamorada. Uhhhhhh.........

yea ... yea.... whatever......we have nice beeches like Islamorada too here in west michigan................JUST WISH THE ICE WOULD MELT OFF THEM!!!!

that sounds like a long haul to pull your Formula. Sounds like fun though.

any others with experience with this. should I remove the swim platform?

I have the newer Silent Thunder exhaust ('99 271 FasTech) and took the whole assembly off. Got much louder outside, not much difference inside the boat as the exhaust is under the swim platform. I did not notice any real difference in speed, but it had to help to get that 50-75lbs off of the very back of the boat.

I also replaced the tips with some angle cut pipes from Eddie Marine with steel internal baffles.

Just for the record, I have Silent Choice exhaust so when I am around marina or docks, I can quiet it down substantially.:D :cool: ;)

anyone else take off their silent thunder B]swim platform[/B]
88-90 vintage?

I had a 242-SR1 which the original owner had modified baffles for more noise. his handiwork also resulted in a rattle in the platform.So I cut baffles out almost completely by reaching thru exhaust openings-notching with hack saw blade, then breaking out with small vice grips. Broke out pretty easily from where was bonded to inside of platform. It was just a pain working thru one opening while shining light thru other opening. Ran the boat like that for a number of years-no negative impact on platform. Platform was still solid when I sold the boat ten years and 500 hours later.

How much louder is a ST system with the baffled removed? I really like the subdued rumble of the stock platform, but am worried that they won't flow enough once I add the blowers.

I considered running the reduced water tailpipes on the CMIs but worry that the platform may need plenty of water to keep it from burning off the boat at WOT.

Decisions, decisions...

I'm running stock 420's in an F311. A LOT of the time this thing is running WFO.

I have drilled out, with a hole saw, one 2.5" and one 2" hole in each baffle. The sound level has increased nicely... but not even close to the point of open pipes.

It has been this way for 3 years and I have had no problems. No performance gains either, however, I woulf think that with blowers the extra flow would be welcome.

Trevor

Trevor,
I'm thinking of doing the same thing to my platform. Where did you drill out the baffle? Did you drill right up through were the stock hole is in the bottom?

Thanks,
Scott

Scott

Actually, I sent out the 4 exhaust tips to have them polished and while they were off I drilled out the baffle via the larger access area from having the exhaust tips removed. At that time I drilled one 2.5" hole in each baffle. The next year I added the 2" hole - mainly because I was to lazy to remove the tips again and that was the largest I could fit in via the exhaust opening.

No melt down has occured. I believe that if you started drilling out the bottom of the platform there would be too great a loss of water within the platform and a meltdown might occur.

Hope this helps

Trevor

Does anyone have an actual or good SIDE VIEW SECTION of the silent thunder? what is the flow. I'm sure the second I took mine off I'd understand but haven gone that far yet.

I wonder. does the bottom hole allow more water to fill INWARD when trolling to muffle the most sound, then when on plane there is little "standing " water actually in the reservoirs/baffles?

hmmmmmmm


boilerdaddy???

My understanding is that the bottom holes are to have plugs in place all the time to permit the water to be traped in the chamber, thereby creating a canaster effect and silencing the rumble.

The plugs are to be removed for winterization, i.e. draining of the water. However, most remove them to remove some of the water when running to make the silent thunder ...... less silent. By cutting open some of the baffle, the water is still inside keeping the platform from melting down, however, the silent chamber is now open above the water line....and ALOT less silent :D

With the baffles removed, the boat had a nice rumble. But, definitely quieter than a regular thru the hull exhaust system. This was with twin small blocks. No performance gain. The boat was run without the drain plugs in the bottom. With both baffles removed & no plugs, the boat ran fine & no effect on the platform. i have seen a few of the big block boats(typ. 292's & 311's)where they had cut large openings in the bottom of the platform. Some for noise, others claimed better performance.

I've heard that by making the holes larger under the swim platform will lower the chances of burning exhaust valves on the big block magnums? Anyone else heard this??

I have an 87 242ls with the 454, holes are open in bottom . Do any of you still have the rubber exhaust flaps on your platforms. These platforms quiet the boat down to much,wife likes it. How long was your drill bit?

I used a hole saw with an 8" extension to reach.

TTT for Formula

Swim platform
 

Rambunctious, last year I removed my platform because of it leaking exhaust around the back of the transom. I replaced a piece of marine plywood that was rotted out from age and water. As I removed the large piece of wood I was then able to see the complete route the exhaust has to travel before exiting out the rear of the silent thunder. I don't believe you will gain anymore access by simply removing the platform without removing this wood as well. Removing the platform from the boat is a pretty involved because the caulk Formula uses is very tough stuff. It takes some time and heat gun to remove all of the caulk. Then to remove the piece of plywood it to is caulk in and encapsulated in fiberglass as well. This piece runs the full width of the platform. Only then was I able to see the back side of this baffle ever one is talking about. Maybe some of the other guys have other ideas but this is what I remember seeing on mine, 1988 242. The job turn out to be much bigger than I expected but I had no choice because of the annoying leaking that was taking place. It all turn out very well I thought but it took some time and a little money for that plywood. Hope this helps you a little, sorry no pictures. Propwash.

The newer style Silent Thunder that mounts under the integrated swim platform looks like it does not touch the water so I assume that it does not get any water into it.

Has anyone modified the new style to gain noise and /or power?

Also, does silent thunder meet the niose laws in place in many states ( and growing daily)?

Re: 272 silent thunder baffle loose, need advise
 

TTT

I have the 4 drain plugs out and the baffles have 5 holes each cut in them.

SHOULD I PUT THE 4 PLUGS IN THE BOTTOM OF THE PLATFORM BACK IN?

Re: 272 silent thunder baffle loose, need advise
 

I removed it completly from my 312, Not that big of a deal and went withh ggb's, Much better, Also i had removed the baffles from my 272 and although it was louder it still had that nice rumble but was well under the 89 db mark.

There are explanations on this forum of how to go about removing the baffles, I for one gave a lengthy one, It is not that difficult, Do a search on Silent Thunder, You will have plenty of reading material. It is explained furter down in this forum under Silent Thuder Rattle, Should find some good ideas.