Cutting the Diffuser Ring ?
 

Why? Please explain why and what it does . Say like on a 4 BL bravo one prop???

Thanks

Rob :drink:

Re: Cutting the Difesser Ring
 

Rob
I am no expert, but the way it was explained to me is, the difusser ring helps to seal the props blades when getting on plane. It helps keep exhaust gas's from getting in the props blades and causing cavitation, thus helps the boat get on plane quicker. Once on plane it doesnt have any positive effect unless you are moving at a very slow speed. But because of the flare in the ring it can cause added drag and slow you down a few mph. How many varies with set up. Its a trade off. If you remove it or modify it, planing ability may be sacrificed, they can be removed and then welded back on if the modification doesnt work to your satisfaction. Im sure Brett, Julie, or Matt can explain it better.

Re: Cutting the Difesser Ring
 

i personaly saw the differance on my buddys boat (mv35) his 35 ft fountain runs 104mph and he cut off the difusser ring and the boat ran 109.9 on radar . i never thought it would make a differance but it did
kevin

Re: Cutting the Difesser Ring
 

difesser? :rolleyes: come on now, spell check is free... :D

Re: Cutting the Difesser Ring
 

I copied and pasted it from another page Is this how daddy ? :D diffuser

Re: Cutting the Difesser Ring
 

Now I know what you're talking about... :D

My understanding is that it helps with planing to cut down on blowout.

Re: Cutting the Difesser Ring
 

Where I come from ,Mississippi we don't talk or spell to good :drink:

What about speed ?I have no problem at all getting on plane I don't even need tabs.

Re: Cutting the Difesser Ring
 

I believe you can gain a little speed by removing the difusser ring. Not sure how much though.

Re: Cutting the Difesser Ring
 

how can i tell if i have one? we have hydromotive iv. thanks

Re: Cutting the Difesser Ring
 

Look at the prop on the end. Either you gots it or you don't.

Re: Cutting the Difesser Ring
 

...wats it look like? lol

Re: Cutting the Difesser Ring
 

That really tells him what to look for? :rolleyes:

Re: Cutting the Difesser Ring
 

The diffuser ring is the part of the hub that flares out or a little lip. If it doesn't flare out and it's just straight then you don't have one. It runs the entire diameter of the hub or the center of the prop. Hope this helps.

Not the best pic but this Spinelli prop does have one. Most Bravos have them.

Re: Cutting the Difesser Ring
 

You're right. I just didn't have any pictures to show the difference. :rolleyes:

Here's a link to Hydro website that shows the diffusiors, the bigger round items. The one on bottom shows a more flared look.

http://www.hydromotive.com/accessories.html

Re: Cutting the Difesser Ring
 

does it have any draw backs or should you always cut it to see some gain?

Re: Cutting the Difesser Ring
 

You don't have diffuser rings on your Q Iv's in the pic.

Re: Cutting the Difesser Ring
 

I believe there are a number of other threads prior to this one which go into this in detail. There have been some disagreements between some thought processes on this subject.

Our findings have been, remove the diffuser if blowout while planing is non existant. Difussers are more inportant with through prop exhaust. Risidual air can be drawn through the drive and cause some ventilation even with through transom exhaust.

Look at it this way, anything dragging through the water does just that, drag.

Strip, I think I remember you to have a high X and poor trim reaction. If the props are surfacing and a ramp on the props is induced, think of the result it creates.

It isn't for everyones application. Discuss it with your prop doctor before you cut it off at the local machinist or in your garage.

Re: Cutting the Difesser Ring
 

I guess I should of search before asking :rolleyes: I figure the ring is for plaining which I dont need and if its for exhaust I dont need that either.

It acted like the trim angle aroung 99 didnt make much diff ,between +1 to 2.50.

When I get the new drives and get a base line with the new motor and props ,then we will see what needs changing :D Its better just to throw mo power to it :rolleyes:


Rob