My two PQ340 Buddies both ordered the gutted exhaust tips on their 496HO's. I have same set up, but without the gutted tips. They are both seeing 80, although BillR is now running Bravo 30's so the comparison is not fair. I am at 79 with Bravo 28's that need some work. Had them York labbed, but am not satisfied. They are all over the rev limiter in fall air and need some more work.

My question is, BillR has put different tips on his boat and wants me to try out his gutted tips. Is it worth the trouble to pull mine, buy Bill's and then try to sell my double set?

Will gutted vs non gutted tips make any difference???

I would guess that with your power and the comparison you just gave us the only diff will be the noise. BTW I got rid of my gutted tips (Corsa) and went to straight through. I have a swim platform that was making it to quiet for me. The gutted tips still had the large chamber and small outlet. Now I have a agressive sound with the option of silent choice.

While we are on the subject, The boat I just bought has Corsa tips. Are they a big RPM robber? I used Rex slip ins that seem to knock the tone down but with a 509 huffier motor I saw no rpm loss.

Come on guys.....I just read the thread about this forum being so slow.....where's the beef??

Is this worth my trouble? Has anyone changed over from muffled exhaust tips to gutted? If so, any difference? If nothing else, it has to let the engine breath better at speed.

Scott,

I too am removing gutted Corsa tips and replacing them with regular 4" (pipe) tips.
It this what you did?
How much did the sound change? I didn't really like the sound of the gutted Corsas. Kinda sounded hollow and dull.
What can I expect upon start up?
Did you gain anything performance wise. I don't really expect any, but it would be nice.

MikeW:

Yes Corsa mufflers do rob power. Too much back presure.

Gutted Corsa's or new straight through tips will allow your engine to gain about 100 to 200 more RPM.

Boating magazine did a test of muffled exhaust a few years ago.
The swapped exhausts systems around on the same boat. The Corsa mufflers were the slowest.

I "ground-out" the flate plate that resides about 1" in the tip it was tacked in three spots, if that's what you mean by "gutted" on my 26/385. That was quite a job with the Dremel. For all that work, I gained 0. Wouldn't do it again on a bet.

Noise has become an issue here. On my blower motor the water entered right before the tips ( 27" from the top of the Gil off shore manifold) With the Rex slip ins. Here in ILyou need to pass a 90 DBL one meter of transom test. Depending on the day it would pass With a Radio shack special DBL meter. It would avg 90-93 for 60sec sampling. I never got a second look. Are any of you guys pressed up against Noise laws?...I know you Mi guys are. If so what have you done to keep the law happy?

Bill,
Yes I installed straight through tips with rubber flappers at the ends. I can't say it helped performance but then again at the time I did the switch I had too many other performance issues going on. With the precise records you have I am sure you will know right away I would not do the change for a performance gain I did it for the same reason I did not like the sound from the Gutted Corsa tips and the swim platform combo. It was worth my time the boat now sounds like I think it should.

Mike,
Yes we have noise laws. I am very careful and pay attention to who is around me. I also have silent choice and use it around Marinas and in and out of my slip. I also have my exhaust switch disabled on the dash so that I can prove that my silent choice is always on of course I have another combo of two acc. switches that I use to turn it on and off
I also no that I'm on the edge and of course some day I may get popped but like I said I am careful and watch out for the law before I take off.

One quick side note, I can't get up on plane with my silent choice turned on I have had to sit there for a while and wait for the law to leave before I could go anywhere

Are the Corsa tips the same as the Gil 4" with the augers inside them or is the a total differant deal?? Are the Gil's legal on nat. asp. engine for sound or are they to loud??