Best Lower Unit for Vector & HST
to question 1: Both boats would run better with a Bobs coned
gearcase. I have tried CLE and Sportmaster cases, but none are as
fast as the Bobs coned. I would suggest sending the CLE out and have
it converted. You will be happy with the results.
to question 2: The HST seems to like about 12 inches of setback.
Less and it will not carry weight. More and you compromise the top
end. I have run the engine at 1/2 inch below the bottom with the
most success. We have run in excess of 100 mph at this height.
The 28 chopper is a good choice as is any good round ear overhub.
You should shoot for 7,000+ rpm to get into the 90's. If your motor
is a bridgeport EFI, and has the A7 ECU, it will be limited at 6900 - 7000
rpm. You will need the A13 to turn over 7000.
a few of these and you should get into the 90's. You may need a 30
inch prop if you chose to keep the A7 box. Good luck on your setup.
Please submit whatever questions you have to IHRTechTalk@yahoo.com. All questions and answers selected will be displayed on this page as they come in. Note: though all boaters are welcome, priority may be given to I.H.R. members. Randy can not be held responsible for any advice given. Though his information and expertise is second to none, he has no control over what you do with your boat. It is up to you to boat safely and act responsibly, and his advice is only to be used as a guidance for your high performance boat/motor of which you are the one responsible for the risks involved.
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