How to get rid of porpus 38 Cig?
#1
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Joined: May 2011
Posts: 576
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From: Varna, IL
I'm getting quite a bit of porpusing at most speeds.It rides good between 38-44mph trim no more than 2-3 on the indicators and 60-70mph with trim as high as about 9 where i start loosing speed.Anywhere between i can run 1 or less on trim and when full fuel i'm running the tabs.Boats a '92 Top Gun HP500, TRS, 26pitch 4 blade turning out.I also boat on the Illinois river which is usually flat as glass which im sure doesnt help.Looking for advice since i havent had the boat long and quite a bit different from my previous 29 PowerQuest.
#4
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Joined: May 2011
Posts: 576
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From: Varna, IL
Thanks. Moved it. And yes tabs solve it. But I hate to do it. Burning more fuel and killing my speed. I was just wondering if swapping my drives would give me more stern lift or maybe 5 blade props? The TRS's arent gunna be hanging around forever but until that day, I was hoping to come up with something fairly simple.
#5
Thanks. Moved it. And yes tabs solve it. But I hate to do it. Burning more fuel and killing my speed. I was just wondering if swapping my drives would give me more stern lift or maybe 5 blade props? The TRS's arent gunna be hanging around forever but until that day, I was hoping to come up with something fairly simple.
I also hear 42's do it too...
running tab is probably only way to help it, or keep drives in a tad during cruising, I rarely use my tabs.. but the mistress rides more level even though it too will porpoise way more then my 32 Baja did..
#7
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Joined: Aug 2005
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From: Between A Womans Leggs in IL
swapping the drives and spinning them in will help with a notched transom..you will loose somw handling tho..what part of the illinois river? i somtimes to to where the kankee and desplanes river meet by the big sand bar..mostly im in moris if i go..
#8
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Joined: Jul 2007
Posts: 3,648
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From: Oneida Lake NY
Have a friend that solved this problem with stern lifting props from b-blades. I believe he tested rev 4s and hydro motives. Both stopped the porpoise, but only one gave him all around better numbers.
He is not on oso but I'll try to call him tomorrow for you.
He is not on oso but I'll try to call him tomorrow for you.
#9
Suprised to hear this, usually it happens on Bravo Guns. The Trs has the balance the boat was designed for. Bblades can help with the porpus. The TRS's were cut with a very conservative, actually too long almost X dimension. Prop technology has come along way. What you need to do is record speed, tab and RPM for everything. Send the list to Brett at Bblades and he will help you. Tab eats alot of Top Gun Speed, no doubt. So this would help with both fuel economy, cruise speed.



