Nasty chine walk

[pcdonovan]

:unsure: I am running a Hydro & Marine with a mac 45. and am currenty running it in with a x548 as a surface drive . Don't get me wrong this thing hauls I purposely over powered the boat just to see how fast we can get it. I maybe get about 60% throttle this thing is flying then I try to give it more gas thats when she starts gettin loose. I don't currently have trim tabs but I have auto bailers where I'd have to mount them. Any suggestions that will help me keep it planted and get closer to full throttle would help.

 

[Scott Schneider]

:unsure:   I am running a Hydro & Marine with a mac 45. and am currenty running it in with a x548 as a surface drive .  Don't get me wrong this thing hauls I purposely over powered the boat just to see how fast we can get it.  I maybe get about 60% throttle this thing is flying then I try to give it more gas thats when she starts gettin loose. I don't currently have trim tabs but I have auto bailers where I'd have to mount them. Any suggestions that will help me keep it planted and get closer to full throttle would help.

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This part: running a Hydro & Marine with a mac 45 .... get the Mac 45 part ... Whats a Hydro & Marine ?

The words as written make no sense :huh:

Is it a hydro or a Mono ?

We can help ya, be more specific.

Scott

 

[pcdonovan]

Hydro & Marine is the manufacturer its a Maritimo Cat 36" with an 11" beam sorry.

http://www.hydromarine.de/hm_20618.htm

thanks

 

[Tofastformellow]

try a 1/4 x1 inch strip of foam under the bow stuck up across the tunnel.

and try to run the strut a little more negative , down a degree or 2.

not an expert on this catt , but we run others similar.

small tabs can help but the tunnel will start making excessive lift at speed.

lastly if you cant settle it, add enough weight at the nose to try to stop the kiteing

helpful suggestion

jason

 

[pcdonovan]

Jason, is th foam to reduce the natural lift on the tunnel? How about a small wing between the tips of the sponsons? You don't think trim tabs would do much for bringing the front down. What I know from power boating is that the since its running suface drive the prop torque is lifting one side of the boat out of the water on each downstroke causing the lifting of one side then falling back the other way, doing this repeatedly resulting in the chine walk. SInce its left hand rotation I was thinking of adding tabs lowering the right tab a little more than the left in an effort to force the left sponson to keep contact with the water.

haha well all these ideas will have to wait till atleast monday. Had a crash at about 50+ mph today broke the carrier for the rudder pivot ( MHZ Rudder 21 )

Unfortunately I think the material is a little too thin that wraps around the pivot. The rudder let loose then my prop must have hit it killing the leading edge. Well I finally find a prop that works and have to get another, or a few more.

Oh on that note is there a way of modifying the prop to reduce the lift while keeping the pitch/ thrust of the prop.

thanks guys

 

[Tofastformellow]

yes ,

the trim tabs will help alot , only a small amount is required to change its attitude.

if its chine walking bad i might suggest a different prop, one thats not so savage.

some octuras walk real bad on our catts nchanging or trying a different brand may help.

a 3rd channel wing would do it on the nose, but it sounds like your charging pretty hard already.

may be reaching terminal velocity !! LOL's

the prop question is for someone else to answer , out of my relms mate.

good luck,

helpful suggestions...

Jason

 

[Tim_Duggan]

Oh on that note is there a way of modifying the prop to reduce the lift while keeping the pitch/ thrust of the prop.

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Here you go!