zt260

It's time to choose an exhaust system. (brand and type)

I built a 540 with a quad rotor whipple that will easily make 1000-1200HP, but I always had silent choice in the past. (that was up to 800HP) Now I think it's impossible to save the silent choice and avoid reversion. I am looking at dry pipes with mufflers or S pipes. Switchable external mufflers are another choice.

Lightning and CMI big tubes are the main brands I am looking at. I want 2"+ primaries I.D. as a minimum.

What do you think? I love the noise, but not all the time.

What a dilemma! HELP..............

blown formula

Call Jan @ Lightning. I have the 1st & only set of his new design dry pipes with internal mufflers. They are rebuildable also. Really a totally new design on the headers & tailepipes. The water actually dumps into the tail pipe 1 1/4" from the end!! No water feed tube at the coupling as the old design did. These are really cool to see. I can't wait 'til I get to try them out. 5" pipes!!
Tell Jan that George from Oklahoma sent ya'.... oh yeah, the tail pipes including mufflers was only $1300 for 2 pair!! That's less than some charge for just the mufflers!! Quieter than straight dry pipes. (and you see no rubber hose connecton between the headers & tailpipes. Good design.

Thunder32

CMI......only way to go

zt260

Spoke to CMI and Lightning. Both told me 6 weeks to build anything. So I have some time.

Lightning has not build one set of headers with 2 1/8 primaries yet, so that could be a while and its untested. The 1 7/8 primary headers with dry mufflers would work, but I really need bigger primaries for this motor to see its full potential.

CMI can take care me with a big elbow top header with 2 1/4 primaries, but the tailpipe is an issue. I am thinking an elbow turned down outside the hull into the water will kill the noise, but still be loud and unrestrictive when on plane. But CMI is not building them like that yet. Lightning said they have and will build it that way on the 2 1/8" header, but who nows when.

So I can go CMI with the shotgun mufflers, but I'd rather work a better muffler solution. CMI said theyve had people modify the muffler to divert the exhast down in to the water at idle.

Anyone have some experience with this?

jrz

The CMI big E-top is avialable with ID's of 1 7/8, 2,
2 1/8, 2 1/4, 2 3/8, 2 1/2, and larger if you need or any combination in stepped configurations. As for a tailpipe turn down we have built a few systems for the new 1075 that are working rather well.

zt260

Jrz-

Who are you refering to when you say "we".
Are you with CMI?

And how can I get these turn downs?

thanks

Cord

iTrader: (2)

If you do a full dry pipe you'll really want mufflers. Are you talking about CMI's shotgun mufflers or Drew Marine's shotgun mufflers? The Drew ones won't do much for your noise.

I don't know what drive you are planning on using. I hope it won't be a bravo. If you are using a speedmaster (you are arn't you?) then the transmission will allow you to use standard automotive mufflers. Mount some Borla mufflers right on the exhaust tips. Run a dry tail up to the muffler and then dump some water into the exhaust right at the muffler. You don't have to dump all the water into the exhaust. One 1/4" hole is enough to keep things cool. Plus it'll help the exhaust drain out on shut down. Dump the rest overboard.

Some people are using turn downs meant for semi's. Just make sure they are stainless on chromed.

zt260

Ideally I would just like the turn downs with dry exhaust. I was considering CMI's shotgun mufflers. If I can use Semi exhaust pipes for turn downs I would be all set. Any idea what they bought and how it was mounted? clamped on or welded? (A picture would be awesome)

Unfortunately This boat does not have room for a tranny, so we have an imco extreme. I know I'm pushing my luck, but 800+HP last year and a soft touch keep her together. Not to mention a spare drive sitting a home for that bad day that we all know will come. I may look into the imco 4X4 with an extension box and tranny in it. But not until I feel it is tried and true.

Cord

iTrader: (2)

I'd recommend at least strenghening the gimble ring. I'm not going to preach any more other than to state that I wouldn't be pushing that much power through a bravo. Lecture over.

I have only seen one boat with turn downs. He used T-bolt clamps. Sorry, but I don't have any pics.

Sandisk

Is Gil still around?