SETUP HELP PLEASE

[mike stover]

Prather Lap Cat 1, Thunder tiger 3.5 mildly modded by Jerry , including cut lower with hp pipe , Dubro motor mount (i think), Running 35% nitro. C/G of 8.5 inches from rear of sponsons.

Setup instructions say to add weight to acheive c/g at 8-8.5 inches, but it takes almost a full pound to get that. Then the instructions say to set the motor height at 3/16" above, bottom of sponsons. And a 2-3 degree neg. angle. Have tried an x637 and the recommended 215.

All i get with that setup is a boat that will not come up on pipe and is very slow.

After moving the motor a little higher it went up on pipe, but once you get anywhere near a corner it will spinout and drive the nose under the water. Sometimes when it comes up on pipe it will lift the right side of the boat out of the water if you are even slightly turning to the right, and it will shoot off to the left.

Have tried all different heights and angles but cant seem to figure this thing out. I know the Lap cat is an old design, but its a play boat and it has a great paint job that i would rather it wasnt just a dust collector.

Any and all suggestions would be greatly appreciated.

I'm readdy to throw in the towel.

Thanks, Mike

 

[TimothyJones]

Mike, Are you In or near a boat club.Go on the IMPBA web site and see what district your in and look at the clubs near by. I would attend one of there races and talk to them. (take the boat with you).

Does anybody consider this a good idea with the problems he is having?

Tim Jones

 

[mike stover]

Mike, Are you In or near a boat club.Go on the IMPBA web site and see what district your in and look at the clubs near by. I would attend one of there races and talk to them. (take the boat with you).

Does anybody consider this a good idea with the problems he is having?

Tim Jones

Tim,

I am in Maine, which is Namba 11 district i think. The next race for thais district is in Conn.

There is another local race in October.

 

[TimothyJones]

We have some outboard guys in the chesapeake club OBMBA. Their boats are fast and stable,like Buddy lowe,James Beasley.They are ate up with running outboards. Hopefully they will respond to your call for HELP!!!

Tim

 

[Tim_Duggan]

I agree - catch up with a club.

In the mean time, turn the boat upside down and put a straight edge along the running pads on the sponsons. If they arent dead flat, fill and sand them flat. the edges at the transom end should be sharp - they look rounded in the pics. The other thing to check is if the boat is warped. If when sitting on a sheet of glass both sponsons don't sit flat, it's got a twist in it, and you might be fighting a losing battle.

 

[mike stover]

Ok,I know this hull is old and prob. not really worth sinking any more time into.

What would be a good replacement tunnel hull to put this motor on?

One that is not last place, but at the same time i cant afford a top racing hull either.

Is the VS1 hull any good? Or any suggestions?

Or anyone that might have a good used hull that they would like to let go.

As i am ready to run this hull through a brush shreader.

Thanks, Mike

 

[Jerry Dunlap]

Ok,I know this hull is old and prob. not really worth sinking any more time into.

What would be a good replacement tunnel hull to put this motor on?

One that is not last place, but at the same time i cant afford a top racing hull either.

Is the VS1 hull any good? Or any suggestions?

Or anyone that might have a good used hull that they would like to let go.

As i am ready to run this hull through a brush shreader.

Thanks, Mike

The VS1 is better suited for a stock engine, not a mod. The 28" HTB Tunnel might be a good choice. There's also the Sniper and Vision hulls.

JD

 

[Kris Flynn]

Vision or the 290 I think would be the best

 

[Tim_Duggan]

A Leecraft would work too for that engine and nitro percentage. They pop up cheap on here from time to time.

 

[camaroboy383]

mike... i run my tt on a htb 290 hull.,, i picked one up for around 140.00... post a want add im sure you will find one...a htb 260 might be a good choice also,, seen as how its a mild engine... im located in ct, bout 30 mins from mansfield hollow... will u be at the next race??? i missed the last one...when i was there,, i think there was only like 2 tunnels,,, but if your goin i might be able to go to hopefully make a class...

anyway,, suggestions above are excellent as far as sharp edges,,twist,,ect...the x637 is spot on for the 1.04:1 ratio lower...i would think the spinning out is to much wieght in the nose when the engine starts to fly the hull... lengthen the pipe slightly to get the coming on the pipe less harsh...alot of issues i had was having the pipe come on way to hard and either blowing over or torqueing like you said...you want the engine as high as possible to the point it wont lose bite in the corners... hinge pin should be square to the ride surface to about 1° of positive..

alden

 

[camaroboy383]

oh ya,,,, i would set your hieght so the bottom of the bullet is even to 1/16" higher than the ride surface... they love to be unloaded...lose the wieght till it gets faster and needs it just to stop blow overs and porpoising... lengthen the pipe slightly to get a less snappy coming on....

hope this helps

alden

 

[dizzy dean]

that boat was designed with a turn fin, i ran mine with a mac/lawless and same mount as yours. i never added weight, i used the motor angle and height to keep it some what stable. my sponsons were straight and sharp. best i got was 45mph before i had an airplane, yhe boat saw lots of air in the beginning.

the vs1 is not for a piped motor, all other hulls are great suggestions.

tim

 

[Jerry Wyss]

Believe it or not the VS1 might be the better choice due to its lower cost and lighter weight. You would be able to add the needed weight for balance, and it will be alot due to all the metal you have back there.Its a better design than the XTR, will be easier to turn than the HTB.

That boat your using now will be a friggin NightMare!Bust that friggin' thing all to hell and get it over with.

The VS1's bouyancy should be able to handle the extra weight and I would bet $ you would be far more successful.

Plus, you would have the privilage of bruising the sensibilities of the elites.

Brian Buass (raptor347 I think) is on here sometimes,, I believe Brian use's a VS1

for his electric O/B's modified somewhat. His electric motors produce power that the O.S.XM can only dream about and he drives the boat accordingly with great skill and cunning,lol. Drop him a PM and

maybe he can give you some tips concerning the VS1.