set-up advise for tunnel hull

[dana]

so i ran this once and conditions were really bad. wasnt quite fast enough either, so tonight i put in ul-1 motor/esc. should rip now. just looking for some advise on these type of hulls. the one run i did notice some porpoising in the turns. not too sure where my outboard should be....is this because my prop is too deep or does the outboard need to go down? i'm running 4s and octura X440/3

[steveo]

try and run it when water is cleaner, its hard to say where the prop should be i had this hull for along time and used it with os .21 motor then a few years ago just for fun i tuned into an fe boat. now this was only an expirement and did not get much test and tune i did seem to me that the prop needed to be deeper but i never changed it

i think due to the extra length of sponson and that it is a stepped hull it planes a little different and may need to be deeper it might not be getting enough bite

i hope this helps i know the boat ran well when it was nitro its all in the set up

[steveo]

is you prop already below the sponson, take a measurement of where the prop is from the bottom sponson to the center of the prop

[dana]

is you prop already below the sponson, take a measurement of where the prop is from the bottom sponson to the center of the prop

the prop is centered with the sponson bottom, just like i would if i were setting up a cat. i figure this is a good starting place

[steveo]

i would say run the boat when the water is nice then report back

[dana]

ok so i got a good run in. boat porpoised a little bit getting up on a plane,then ran smooth at full throttle. it def porpoised in the turns ( which were taken sharp ) and rode on the very rear of the sponsons in the straights. should the boat ride more level? or is this normal? how do i get it to stop hopping in the turns? thanks

[steveo]

if you ever watch these boats race on tv they are on the ragged edge, as long as the boat stays on the water and have as much boat out of the water that you can then your on point. try not taking sharp turns but a nice sweep like you would during racing, they all might bounce taking sharp turns i dont know though

[properchopper]

ok so i got a good run in. boat porpoised a little bit getting up on a plane,then ran smooth at full throttle. it def porpoised in the turns ( which were taken sharp ) and rode on the very rear of the sponsons in the straights. should the boat ride more level? or is this normal? how do i get it to stop hopping in the turns? thanks

Tilt the motor with a few degrees negative [ prop angled down] & move CG back to compensate. This has worked for me.

[LiPo Power]

Try M445 prop...

[dana]

i will try chopper. my second run i tried to pay closer attention. i noticed that the boat almost wants to come out of the water cause its so fast. second i noticed that it runs smooth on flat water but starts to porpoise when it runs over its own wake, and doesnt stop till i let off the throttle. lipo...what will m445 do?

[HOTWATER]

When I bought mine, Remy told me that if I wanted an increase in speed to move the motor back 1 1/2" from where it normally would mount on the transom. I made an extension and I tried it... he wasn't kidding! Definately a gain in speed and it made the boat seem "bigger". Also helped spread the workable CofG out a bit....could be worth a shot Dana......

-Kent

[bigwaveohs]

I agree...the lower unit/hinge pin is way too far inside the rear of the sponsons. Needs a lot more setback...

[dana]

interesting... im thinking if i just use the stand-offs people are using to offset the miss geico rudders i could mount the whole bracket to those..... but will this help with handling as well? cause its really quick the way it is. what speeds are these hulls capable of?

[bigwaveohs]

The setback will give you more OAL which should lessen the tendency to blow over...

[HOTWATER]

Yep! More stability....although, at a high enough speed, she will still take off out of the water...

Here's a pic of the Dubro mount I used. I took the black peice to a machinist and had him duplicate the peice out of aluminum (and had holes cross drilled through the sides to lighten it up), but had 1-1/2" of length added to it....very strong...worked like a champ!

I'm sure there are a couple of guys on here or IW site that could EASILY make that peice for you.....