Corsa muffler question
 

I'm trying to get my 353 with 500 EFIs under 90 decibels. Formula is recommending 6" Corsa muffler as follows;

Part # 63430 EXHST MFFLR W/FLP 12600-ITPC1 PR

Has anyone had any experience with these with 500 EFIs? I'm curious if they got you under 90 decibels and how much power loss to expect.

Re: Corsa muffler question
 

I would take a look at the GGB's Biggus on the board put them on his boat and got HUGE db drops with no loss of power.

Jon

Re: Corsa muffler question
 

HPI s are what the Cig factory uses.My 525,s with HPI are quieter than my 500,s were with the Corsa.

Re: Corsa muffler question
 

353,

I talked to the Factory Rep at the Formula Rendezvous on the Chesapeake Bay and after looking at my set up with 525s, Silent Choice and the Corsa mufflers, he was concerned that I was constricting the engines too much with the mufflers. I ordered the boat with mufflers and no box because I feared the 525s would be too loud. Whatever you decide on, an effective switchable muffler that lets the motor breath is superior to the Corsa muffler. The problem I have seen on the Potomac with the switchable clamp-ons, is most guys are having problems with them working properly after a year or so of operation. This seems to be a common problem for the pneumatically operated muffler setups.

Am in the process of changing to straight tips since I have the silent choice. Our opinion is that our 382 is too quiet with the Corsa mufflers. Unfortunately, when Formula installs the Corsa tips, they cut the four standard studs off and weld three larger studs on about a quarter inch from the edge of the muffler. This has resulted in my having to fill and re-gel the existing holes because they extend beyond the diameter of a standard 4" tip (which is 6" in daimeter with a 1" trim ring). I should be finished this weekend.

Note, if you had the box before, there have a been few members that could not use clamp-ons with the existing tips. If you have to pull the existing tips, its not too bad with 525s but you have to pull the exhaust to get at the tips from inside the boat. 500EFIs should be about the same difficulty.

Bill