Anybody ever torn the guts out of a Silent Thunder? If so what did it sound like afterwards?

DaveHam

If you have a 97 312 then yes. I removed the entire box on my 98 312 last winter. Wife was pizzed that it was going to be too loud but she never realized the difference unitl the second run in the spring when i pointed it out to her....she never noticed! I could hear it, a deeper rumble but not significantly louder. (stock 502 mags, stock exhaust)

DaveH or D. P.

You must be referring to PAYUP ! hehe
I think it's going to sound like my 89' 272. But I think it will restrict flow with that other exhaust system

Don't you?

Dan R
mtgbiker

Mine is not gutted but has 3 inch diameter holes in both bottom corners and 2 in the center . This makes the boat illegal per SAE specs (113 dB). It still wont hold enough water at idle to muffle the noise. 502 MPIs in a 311.

Gutted?? There's nothing but one or two baffels inside.
And yes, you can remove the baffels to get a better sound.

I cut two 2 1/2 " holes in each baffle and doubled the outlet flanges on my 311. Sounded good, not annoying.

I think he's talking about the newer style "box" that fits under the swim platform, not the older SR-1 type that IS the swim platform. (See 97 312 in his profile)

The baffling inside doesn't do much to affect the sound. The muffling that the ST provides is due to water retained inside the ST. If you start cutting holes in the bottom like Insptech did then you're going to start making it louder because there won't be enough water inside to damp the sound.