is there a way to get a little more sound out of them just a little to quiet

full-time or part-time mufflers?

If they're part-time mufflers and you don't intend on using them I guess you could always cut the flapper out but I'm not sure how much of a difference that would make...

Interesting question, I'm curious what others have to say.

they are full time the centers push out when get on the gas

I believe the piston in the middle if it's the ones I am thinking of are spring loaded maybe you could manipulate the spring.

Not sure if you can make them louder but I was wondering if you lost any speed on the top end? Are they too quiet when they open up or just at lower RPM's? Steve

Wondering the same thing also. There not suppose to rob any power however I don't know first hand. I can't really see where you could do much to them without ruining them. I have 2 sets of 4" that I bought for a friend of mine and know he doesn't want them.
Bummer.... Anyone looking for a couple of sets.
John

If you can somehow modify the piston so they're open all the time that might help. How are the noise police by you?

I know when I installed my switchable Gaffrig mullers on my dry pipes it took the bark out of the idle, even though they weren't closed... Since I've bolted them on I've hardley used them, go figure!

I have a set of the 4.5 x 6's, on Twin 500 EFI's. They really quieted the boat down! Especially at idle. It is nice that you can now talk in the boat and hear each other. At speed they open up, but it is hard to tell any noise differences at speed with all the wind noise and such.

I did not notice a loss in performance or top speed.

The fit and finish was a little dissapointing. One pair looked great and fit perfect. The second pair did not! I sent two pairs back for quality issues before I got a second pair that matched the first in terms of quality.

You could un-bolt them in about 15 minutes if you want to got back to the "natural" tone.

i have the cmi mufflers on my boat with 632ci motors,they don't seem to hurt top end speed at all,but i would like more noise at idle.they welded mine right to the tail pipes and they look good,but a hot rod is supost to be noisey.i might remove the insides of them