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outlander

Smaller Engine Boats

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In South Africa we have a newly formed "hardbottom" amateur racing series.

All boats have to be 2 seater with pilot and co-pilot.

There are 4 classes Class 1: up to 130hp Class 2: up to 200hp Class 3: up to 225 hp Class 4: open

Racing ranges from longhauls (approx 150km say 95miles) and circuits (similar to F1)

My questions are:

1. Most of the faster hulls (STV / Eliminator etc) seems be be very suitable for bigger engines 225hp and up

Which hulls are more suitable for the smaller engines or could you modify to suit?

2. Most of the topics and videos are about top speed and straight line runs - how do you set up the boats for circuits - obviously you drop the motor and move closer to the transom and prop for accelaration, but are the other issues as well? In general hoes does a STV handle turns and wakes?

I would appreciate your comments - thank you

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200hp engine should net top speeds of about 90mph. STV's were orignally designed for racing on circle courses and in my opinion the mod-vp bottom is the best choice. The mod-vp bottom settles down quickly and can turn very sharp. Maybe some of the long time STV owners can add to this....

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look at the smaller hydrostreams with the xt and yt air intrapment hulls. there fast turning and will handle the up to 200hp. my 20' voyager will spin if running under 35 and stays flat up to 50. just depends on the speed necessary to be compitive.

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look at the smaller hydrostreams with the xt and yt air intrapment hulls. there fast turning and will handle the up to 200hp. my 20' voyager will spin if running under 35 and stays flat up to 50. just depends on the speed necessary to be compitive.

Thank you for the response - and excuse my limited knowledge. If you talk about smaller hydrostreams, is it variations of the STV hull or different hull types? If it si different hulls, which makes / models? Please explain xt and yt intrapment hull (never even heard the terms...) If you say your 20' voyager spins under 35 does it mean that it will spin out in a turn (not bite an go wide) if you are under 35mph? Thank you.

To answer your question about competative speeds. We need to achieve close to 65mph for a 130hp motor - 80mph for a 200 hp and just over 90mph for the open class (most people in the open class fit a Merc 2.4l Brigdgeport or the ex F1 2.5l engine) - any comments?

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spin was the wrong word, i really mean turning in a control way.

the xt and yt hulls a v hulls in nature with air tube carved in the side of the v. at the speeds you talking you really need a true stv type of a hull. thats the only way your going to get the speed and turning ability. my 20' boat can reach 75 with a 2.5 200hp merc but turning a that speed is not very sharp. i have to trim the motor to netrual and drop the speed tp 50 then turn. that turn can be in 100-150 and fairly flat. that would not be too competive.

look here for some info and old racing info. they even have picture of the different hulls types.

http://www.hydrostream.org

To answer your question about competative speeds. We need to achieve close to 65mph for a 130hp motor - 80mph for a 200 hp and just over 90mph for the open class (most people in the open class fit a Merc 2.4l Brigdgeport or the ex F1 2.5l engine) - any comments?

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