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Why is she blowing out of the water, set up help please.

Old 10-26-2010, 07:58 PM
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solar696
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Default Why is she blowing out of the water, set up help please.

I am looking for help or setup advise what to do to stop the hull from blowing out of the water.

This is an enforcer super G hull. 46" V. Everything is replaced but the gas tank and the radio box.
Stock zen 260 engine, 257 carb, tuned jerone replica stainless pipes. tops out about 44-45 mph then she wants to leave the water. upwards. And did it a couple times.
I think she would go a bit faster but can not hold full throttle.

I have attached some pics to see the set up.

The engine is moved forward almost touching the gastank.
strut is lowered (it seems) below the hull line,
trim Tabs are about parallel to the hull- I did not want to move it further down to minimize drag.
Square drive propshaft.
Prop is a prather 275 stainless.

It seems she runs best when the gas tank is filled to the rim.

What do I need to do to keep the nose down with out creating much drag in the back.

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Old 10-26-2010, 08:10 PM
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Paul M
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Default RE: Why is she blowing out of the water, set up help please.

Welcome to the age old dilemma - Do I want it stable or do I want it fast.

I'd lower the tabs a little at a time. They look pretty high to me. I would also try some different props. Monos aren't my thing so I can;t suggest which one but I am sure someone will chime in.

Someone may want to correct me but I think mid to high 40's is about all those hulls are good for anyway aren't they?
Old 10-26-2010, 08:19 PM
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Default RE: Why is she blowing out of the water, set up help please.

What I would do is check the boat's balance first. I'd mark the hull at around 27% and again at 33%. Next see where the boat balances, if it's not in that range, you are either nose or tail heavy. Since it's blowing off the water, if the boat's tail heavy just add a little weight to the nose to help hold it down
Old 10-26-2010, 09:01 PM
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solar696
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Default RE: Why is she blowing out of the water, set up help please.

Just came back from the garage and measured, the hull is 46", it balances at about 13.8" from the back which is 30%.
with gas tank about half full.
The measurement was with the 46 inch hull only not measuring all the junk that hangs out in the back- pipe, rudder, prop...
Old 10-26-2010, 11:49 PM
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Default RE: Why is she blowing out of the water, set up help please.

I think Paul nailed it. I am not sure she will be very stable beyond lower 40's.

You could add more weight to keep it in the water but I am not sure if that will be adding stability or just slowing it down some.
Old 10-27-2010, 01:19 PM
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Nosedragger
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Default RE: Why is she blowing out of the water, set up help please.

looks like the strut is too deep and too much neg, make the bottom of the strut parrallel and above keel about 1/8" and try it again.
you are dragging the strut and prop hub with the setting you have now
sharpen the prop also, it doesn't look sharp

If the bow rides to high, put some negative in the strut but don't lower it
Old 11-27-2010, 08:18 PM
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drydock
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Default RE: Why is she blowing out of the water, set up help please.

I know this is an old thread but I just ran across it because i now have a 50" Apache. It seems to me the trim tabs should start out as an extension of the hull bottom. Your initial mounting seems high to me. With neutral tabs mine seems flush as my fingers glide from the hull to the bottom of the tabs...
Old 11-28-2010, 12:05 AM
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Scott Schneider
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Default RE: Why is she blowing out of the water, set up help please.

ORIGINAL: solar696

Just came back from the garage and measured, the hull is 46'', it balances at about 13.8'' from the back which is 30%.
with gas tank about half full.
The measurement was with the 46 inch hull only not measuring all the junk that hangs out in the back- pipe, rudder, prop...
There is a LOT of the issue. Current spec monos with this type power run a C/G range 31-35%
You also going to fight the fact hull is a shallow V with high lift strakes, faster it gets pushed drier hull rides.
* Also need to lower tabs mounting on transom so bottom edge is only @ 1/16-1/32" above ride surfaces. This will allow a small angle in tab deflection better holding hull down a tad.
Old 11-28-2010, 07:16 PM
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MrMikeG
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Default RE: Why is she blowing out of the water, set up help please.


ORIGINAL: drydock

I know this is an old thread but I just ran across it because i now have a 50'' Apache. It seems to me the trim tabs should start out as an extension of the hull bottom. Your initial mounting seems high to me. With neutral tabs mine seems flush as my fingers glide from the hull to the bottom of the tabs...
Since you brought it up, then no level is constant drag, 1-2mm up from the bottom allows only the tip of the tab to contact the water which does the same job but less drag.
Old 11-28-2010, 09:37 PM
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Default RE: Why is she blowing out of the water, set up help please.

Can a change of rudder angle have a helping effect?
 Just a thought.
Old 11-28-2010, 10:15 PM
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solar696
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Default RE: Why is she blowing out of the water, set up help please.

The trim tabs were installed by enforcer/warehousehobby, it came like that when I bought it many years ago. I did not mess with it , I had confidence in the builders so I did not mess with the trim location.
I will move the motor forward a bit more along with the gas tank and see how she does.
thanks
Old 11-29-2010, 03:14 AM
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martno1fan
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Default RE: Why is she blowing out of the water, set up help please.

Yes tucking it in raises the bow angling it the other way does the oposite.
Old 11-30-2010, 06:38 PM
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Default RE: Why is she blowing out of the water, set up help please.

Yea your right, I got it backwards. [:@] It might help to try this.


having this much fun must be illegal

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