Tunnel Hull Setup ???

[steinersamuel]

So I finally tracked down a PTI Racing PX335 kit and it will be on its way to me shortly. Ive got a power system laying around already, so its what I'm going to use. Its a Leopard 3674 2650 motor on a OS leg with a Swordfish 220 Pro +. I know there's going to be a lot of people saying UL-1 system blah blah blah lol, but I'm not racing, just running for fun at the cottage. But I'm just curious what everyone else is running in their tunnels. Whats the HOT servo and linkage for these, and what power system and batteries you are running. I know there is an art to tuning a tunnel properly with prop depth, angle, and CG, and I will have to learn that. But trying to see whats out there.
Thanks everyone!

Pics are welcome

Sammy

[Doby]

Whats the size of this hull?

[steinersamuel]

Hull length is 33.75". newest 001.JPG

[Doby]

Nice looking hull.

I assume you are going to run 3S on that motor....the kv is a bit high for 4S.

You will want to run a metal geared servo.

[steinersamuel]

Nope, gonna run 4s lol. I know its a bit much, but for the brief time i'll be able to hold it wide open should be fine. had the same setup in a CF Daytona with no issues. as stupid as it was, even saw 5s for a brief run, was on its lid in no time!!

I figured a metal gear servo, some are better than others tho and wasn't sure if some have had better luck with one vs the other.

[siberianhusky]

As far as linkages I use pull, pull cable systems on outboards. Never had much luck with solid pushrods, they never seem to end up in exactly the right location after you start tuning then bind or rub etc....

[steinersamuel]

Good to know, Thank you!

I've seen both and wasn't sure on that. plus the cable would be enclosed in a tube and not be able to rub on the side of a battery or something like that.

[Doby]

Remember tunnels dont turn well unless the prop is moving!

[steinersamuel]

Remember tunnels dont turn well unless the prop is moving!

Not sure I understand

The boat doesn't move at all unless the prop is moving lol

[Doby]

With an outboard, when you steer, you turn the prop, which is essentially your rudder as well. If you are not on the throttle, the skeg of the outboard unit is now your rudder and with the prop not moving (providing forward movement) the skeg does next to nothing if you try and turn.

Kinda like a seadoo with a jet drive..they don't steer unless you are on the throttle.

[steinersamuel]

Funny!!
I was thinking about that later and figured thats what you meant!
sorry to be a wise @33 lol

[Doby]

No problem :)

[Fluid]

As far as linkages I use pull, pull cable systems on outboards. Never had much luck with solid pushrods, they never seem to end up in exactly the right location after you start tuning then bind or rub etc....

Pull-pull is best from an engineering standpoint, but the use of a good digital servo would solve most problems with pushrods.




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[olwarbirds]

Sam, I use pushrods in mine. I have them routed thru pieces of secured cf rod to keep out the flex or chance of rubbing etc... I really have gotten to the point on all my hulls 29" and up of using Savox servos...me being the speed freak I am would run that on 4S too...my buddy runs a 1515 2200kv on 4S in his 29" tunnel and its impressive...it is going to be very sensitive to cg. Also start small on the prop, around a 42mm, 642 maybe....I know your going to really like this hull as much as I do mine... DJ

[steinersamuel]

Cant wait!! Its in the mail as we speak!!
Never had a savox but heard good things. What model are you running DJ?