gary cook

I dont know why your boat runs the speed it runs but i can tell you weight makes a huge differance.
7250 lbs light on fuel remember that boat still is running 102mph and its been 10 years since i have had it.
X height means a lot my velocity losses 5 mph by droping the drive .250
Heres another boat a friend of mine had 30 awesome 500 bulldogs x at same spot as mine hook taken out 100 mph but it was 900 lbs more than mine.
If you want send your number and ill tell you all the changes i did and props to much put on here.
Gary

tssteph

Is the hook your talking about in the sponsons or in the tunnel?

gary cook

Its on the last step its the flat running surface.
Most of the pleasure boats had a big hook in them and it worked like a big trim tab one side was worse than the other on my boat.

tssteph

My AO does not have a hook.

gary cook

Thats good one less problem to worry about.

tssteph

I guess I should have said on the steps. It does in the tunnel. The last three feet or so hook quit a bit.

ROTAX454

Let me first say that you being an Offshore racer provides enough validation that you know how to properly "set-up" a boat for it's max potential. Or better put, you have forgotten more than I know.

I am curious since I really don't know, so I will ask. Clevers. They are made for a bravo lower? Or, you can adapt a sportmaster lower to a Bravo 1 upper?

Jim Jones did tell me that he had worked with Tom at Hydromotive on props for the 31. He did say that Tom knew how to correctly prop the 31.

gary cook

Props back then werent as good as they are now that being said a bravo 4 blade was a good all around prop merc 4 blade outboard cleavers were fast and thats about it.
Back then thats what a lot of the super cat light guys used was outboard and 4 blade quad 4
I raced with both depending on how the water was and i tested with a ton of props that werent as good as theses two i ran .


Yes the outboard 4 blade cleaver will work so will the 3 blades i tried the 3 blades ran ok speed but handle wasent great.

And it was real fun to get on plane with 3 blades.

Like i said in the above post x height was the biggest key to speed but the trade off was a bad low speed hop you have to make the prop surface to get rpm.

A tunnel tab would have helped the low speed hop and if you can believe it i shouldent even say this maybe a touch more speed.

My boat now looses 4 to 5 miles per hour with .250 to .500 drop in drive height depending on drive trim angle it goes from 94 to 90 or so.
The water speedo picks up 5 miles per hr when its at its lower setting the water speedo is dead on to my gps speedo at the higher drive height .

So that tells you what water pressure is doing without even putting a pressure gage on it.

Plus my old boat had no cabin and weight moved around i also talked to george lender a lot about things to change he is the guy who made the first chris cats and sparky at vicious had a lot to do with making it run the way it did.

CNC

Fascinating, I had never checked for hook on my bottom step. Just checked it is .125 to .188, not much.
how much is typical? I am always tweaking my setup, I have #5's with 12" extension boxes, prop C/L 2.75" from bottom.
Randy

LASTCALL

Nice to meet you Gary. I am back from a week trip in your area, (i was in Michigan City SBI race...but no race) visiting
Chicago etc.. And what a week of action i miss on the forum!!

So your are the original owner of the boat. How did you reconized for sure ?. And, to anwser few questions..
Those 500's hp stil have the seal on it. Port read 155h,and
stabord 175h. The lower std bravo's are now XR shaft. With
the same 1.36 imco gear upper.

Serge (from Montreal)