has anybody used them before? interested in the 4" x 5.5 sport inserts for a twin 496 boat, has anybody used them with any luck ??

Thanks

GGB 4" x 5.5" Marine Sport Insert | Outdoor Supply

I have used there product in both a merc twin 520hp boat and a twin ilmor 725hp boat. there was a noticeable difference in both cases in the sound level and pitch. it took out the high pitch cracking. I did not notice any performance change. They are a great company to work with

I run the GGB inserts in my 525 Formula 400ss. I bought the 8" and ended up cutting off 1 ring.
Great product. Love the sound of them.

thanks guys..
so the 5.5" are smaller because I dont have room in the tips for larger ones,,,the ones I was looking at have 3 rings,,has anybody used them?

I bought the 5 ring units for my stock 496. I have corsa switchable exhaust as well. With the 5 ring units it was just about as quiet if I ran with the exhaust going through the prop. No speed lose either. I actually cut 2 rings off to make them a 3 ring unit. I bit louder at idle (not to much) and almost as quiet at cruise and WOT. Great product and would recommend them.

I would like to weld a tab on the 2 rings I cut off and try a 2 ring version.

great,,so the 3 rings made a difference vs nothing at all?

absolutely

boatnt, If you decide to order a couple pair Pm me for a price.

I use the 5 ring sport inserts and have had great luck. Actually makes a better/smoother V8 sound. Zero reduction in WOT rpm as compared to other inserts with the same dB reduction. I measured a sound reduction of 6 dBs at idle 3" off the transom (while on the trailer) as compared to no insert. FWIW other inserts I've used offered the same 6 dB idle reduction but also choked off the motor 300-500 rpm at WOT.

Summary: Recommended.

I have twin 525SC with 5" tips was thinking 5" X 5.5" 3 ring competition. I don't think I have room for anything longer and clamp on's would be tough.
Thoughts on DB levels?