Who is running Gibson Bullet mufflers?
 

Anybody out there running Gibson Bullet mufflers on a 600cu/750hp NA motor? They claim no power loss, i'd like to hear from someone, before/after, did you lose top speed or not?

And DB test results.

I have not run Gibson, but have tried CMI's and GGB's. Neither effected speed/rpm in boat. I don't know about HP as no dyno done. However, neither of these were effective in meeting our noise law (90db) on my 598 N/A engine, 10:1. They do quite it down quit a lot but not legal.

I went from 113db to 94-95db.

I currently have downturns and are in the 80's.

Rick

I ran gibsons on my 650 HP blown 509's. We lost a mile or 2 per hour but the boat had a nice throaty rumble. Never pulled over by the LOTO Wp with them. I'd guess though we were over the limit but a lot less than many w/o mufflers.

I'd own a set again.

Hi,

I have two pair for sale...I used them for about two months and then sold the boat.

I noticed a considerable decrease in sound. I never really pushed the boat so I can speak about loss in speed or power.

Call me if would like to pick up a barley used set (fresh water).

Chris
323 864 8332

How much? clamp on or transom mount?

I'm not so much concerned about being right at 90db, I just need something to take away a little of the bark. My boat has a top speed of 122 now, if I put these on and it runs 119 I can deal with that, if it takes away 10mph that's a different story.

Ron Gibson= good guy.

And what diameter?

Just FYI, I have a set of brand new 4 1/2 dia inlet x 6 CMI Clamp on mufflers for sale. They say these will not affect your HP or RPM at all for up to like 1200 hp while the 5 inch ones are only good up to 525 HP.

http://www.custommarine.com/accessories/Silencers.php

4 inch clamp ons

$475 + shipping (4 in total)

Chris
323 864 8332

you can expect a 8-12 dcb drop with the clamp on's. they all will reduce performance, but it will vary. turn downs unless they have above water reliefs and are above water line while on plane will effect performance. have tried over 8 company's mufflers

Tazz,
I just ran them for the first time and lost 300+ RPM on my blown 509's. Quiet and look good but.... Gonna rejet and see if that could bring the revs up a little.

shoot need transom
thanks

????????

That's what I was afraid of, I was sceptical whan I read the test on their website and it didn't test for top speed loss.

Any interest in my Gibson's
Call me 323.864.8332