Pursuit Outboard Setup?

[Snowride]

I have a virgin Pursuit hull on the shelf which has been there for a couple of years. I recently purchased a ARTR tunnel hull outboard setup from HK and really like this outboard stuff. That being said I do have a spare outboard, and everything else required to set this up. Problem is I need to know at what height do I install the prop shaft in relationship to the hull? Should I install trim tabs? Turn fins?

Although the hull is longer the weight is nearly the same when I compare the 2 boats do you think this will work? That being said I hope the hull efficiency is not that far apart to allow me to actually get up and out with the Pursuit with this rather small outboard.

Can someone point me in the right direction for determining CG when installing batteries on this.

[siberianhusky]

Prop should be at the same depth as a "normal" setup, same with the cg 27-30%. Used to run a Prather mono with an outboard on it years ago, was much faster and handled better with an inboard, suffered an AM radio issue and destroyed my Hotshot Tunnel, was young and broke thought an outboard would be a cheap easy setup so I could keep racing that season. Lots of help from the older guys but that hull with an outboard was always an also ran....
I have no proof of this but I think the really high vertical CG effected the hull in turns, wasn't bad in the straights. Very well could have been the outboard though, don't like outboards where the shaft angle is adjusted along with the turning pivot, like K&Bs, think the angled thrust causes issues in turns. OS outboards have a much better setup for adjustment.
Funny, still have that hull in the basement, been dragging it around since the 80's.

[Snowride]

I am going to try this unless someone else thinks this not going to work. Bottom line is it is only 4 small holes to repair if it needs to be changed to a conventional setup. Might even go with a universal plug and play Traxxas Spartan motor tray in there.

[siberianhusky]

4 holes to mount it, 3 for the motor wires and 2 more for steering cables. I prefer a pull/pull system for steering on outboards, PITA to get a solid rod system lined up, there always seems to be binding after you get the prop depth and angle set, no matter where I think is "right" on the bench while building never actually seems to be right!
Best of luck, really hope it works out for you, no fun putting effort into a project then having less than ideal performance.
One thing I hadn't though of with electrics is you will probably end up with some really long wire runs, your packs will have to be far forwards to get the CG right, that boat of mine was nitro and took a pile of lead in the nose, at least the batteries are useful ballast. Lot of weight hanging behind the transom.

[Snowride]

Actually the outboard only weighs slightly less than 7oz. Only 1 hole is required for the motor wires. The steering rods are easy to line up, trick is to locate them where you think is best on the bench then if required to move the outboard up or down just adjust by bending the rods accordingly. The steering rod holes can easily be used as water cooling exits if I change the setup. The wire hole would need to be plugged though.

[siberianhusky]

Impossible for a complete outboard setup for a Pursuit to weigh in a 7oz! A motor big enough to run that boat by itself will weigh more than 7oz.
Ah just checked the OSE store page. http://www.offshoreelectrics.com/pro...prod=OSE-80980
If this is what you have it's not the right unit for a boat the size of a Pursuit. Way to small. Even a pair wouldn't work very well.
http://www.offshoreelectrics.com/pro...dh-os-23871010
This is what you need for a boat that size, with about a 36-40mm diameter motor minimum 74mm can length on top of it.

[Snowride]

Thanks for the input, need it as I am a dangerous newcomer. Actually have more money than brains when it comes to RC boats. I am using a mini outboard on my tunnel hull as seen here in this thread. http://forums.offshoreelectrics.com/...-Hull-Outboard Want to try this same motor on the Pursuit. I know it is not very big however it can easily push the tunnel hull to at least 46mph which is rather impressive considering everything is basically cold after a hard all out 10 min run.

That being said, today I increased the prop diameter from 32 to 35 on this same outboard but have reached the limits of the motor wiring as I managed to melt the connectors to the motor today after I hit 49mph. I probably could have taken her to 50+ but the little pond I am on although quite big is actually small when you are doing 50.

I have a feeling it may put a strain this poor little outboard but what heck, worth a try isn't it? Like I said if it fails, time for a conventional inboard setup. Thinking 3674 1600kv on 6S or 1300kv on 4S hooked to a 180A Turnigy ESC. Heck even have a couple of 1600kv 4082 on the shelf that could be used but I think they would be overkill on a Pursuit. Already have all this stuff so might as well put it to good use.

[siberianhusky]

4082 is a popular motor in the Pursuit, some go even bigger! It's a good hull that many people have pushed really hard. Castle or Neu 1515 1y is also a common motor.
I have a 29" version with a Castle 1512 in it, running a cut down 1450 prop, thing flies but my batteries are not quite up to the task, come in a bit warmer than I like. Motor comes in cool.
A mono hull has a lot more drag than a tunnel, needs a lot more power to push, if you're at the limit in a tunnel with a 35mm prop You probably wouldn't get 20 out of the Pursuit and will burn up the motor.
The tunnel hull packs a cushion of air between the sponsons, this helps lift the boat out of the water, properly set up a tunnel should pretty much be flying down the straights.
My 29" boat pulls over 100 amps on launch then settles down to a constant 70-75 ish. Running about 50mph for 3 minutes.

[Snowride]

4082 is a popular motor in the Pursuit, some go even bigger! It's a good hull that many people have pushed really hard. Castle or Neu 1515 1y is also a common motor.
I have a 29" version with a Castle 1512 in it, running a cut down 1450 prop, thing flies but my batteries are not quite up to the task, come in a bit warmer than I like. Motor comes in cool.
A mono hull has a lot more drag than a tunnel, needs a lot more power to push, if you're at the limit in a tunnel with a 35mm prop You probably wouldn't get 20 out of the Pursuit and will burn up the motor.
The tunnel hull packs a cushion of air between the sponsons, this helps lift the boat out of the water, properly set up a tunnel should pretty much be flying down the straights.
My 29" boat pulls over 100 amps on launch then settles down to a constant 70-75 ish. Running about 50mph for 3 minutes.

Really appreciate the feedback, saved me all this work only to find out it will only get 20 mph out of her. The outboard on the tunnel basically turns it into an airplane. Nothing is touching or should I say the last 1/2" at best and I question that. Very touchy on the trim angle with about a mm play before she flies or just scoots.

I will be putting in the Traxxas Spartan motor/esc/receiver/drive shaft tray into the pursuit. Always loved the idea of having everything on a removable unit. They did get that part right. All I need to do is build some side mounts to take/secure the Spartan tray.

I do also have a Spartan which has a 4082 already in her which I could simply slip into the Pursuit so basically everything is there except for the battery tray. This is going to be fun.