What about tunnels.

[sjhauge]

Let's get it started again. ;D Tunnel talk at it finest.

 

[Ron Olson]

Hopefully Tom can move all of the old stuff over here. we might have to give him a little time though, there's a lot of stuff to move! How about a "What about monos?" and "What about 'riggers?",scale, electric, etc. to help separate the threads.

 

[TomMoorehouse]

do you guys want forums that are forum specific?

i know a poll question!

i an trying to get a developer to make a converter from our old forum...

 

[ggillman]

SJ, I saw you sold some stuff, what are you planing on running next season? I am building up another Sprint for testing out some ideas.

All you other guys running tunnels, what would like to see happen in the next generation of tunnels comming out?

Gene

 

[Ed Radz]

Ok experts!

I just picked up a 3.5 tunnel that I'm going to try this spring. I know nothing about tunnels. How about a clinic here on theory on how a tunnel works, how to set up, and how to drive it!

Thanks for your help!

Ed Radz

 

[ggillman]

Hi Ed,

There is a post on the old forum called

"What About Outboards" its 14 pages of info on setup and tips and tricks for the tunnelhull, very good reading,

check it out, here is the link:

http://intlwaters.com/cgi/index.cgi

The old forum is read only, please return here for any posts, Thanks

Gene

 

[sjhauge]

Gene,

I am just about done with an HTB 290. Just need the lawless. The stock hull is still in question ??

Check your email

SJ

;D

 

[TimD]

Hey Guy's,

I'm back at last!

Just thought I'd let you all know that my new tunnel is finished and running. The Nova/Lawless works very well with the CF pipe and the hull handles very well in the windy conditions I have been running in this last week!

The details for you "regulars" on the old outboard thread are as follows.

Hull weight = 4 1/2 pounds

Prop distance from rear edge of sponson = 5 inches

Hull length 27 inches and CG set 220mm from rear sponson edge.

With this setup the boat was stable in strong wind (enough to blow the tools off the pit bench!) and doing high 40's on 25 % nitro (air temp / humidity / density very poor)

I'll post more details when the weather impoves here.

Tim.

 

[Ed Radz]

I've read all the old posts from "what about outboards". My questions is on figuring the CG on a tunnel.

1. Do you figure the CG with the motor on and all radio gear installed?

2. Is the hull length measured from sponson tip to sponson end, or to the prop nut?

3. Is 30% from the back the correct CG point?

Thanks!

Ed Radz

 

[Grimracer]

Ed-Ed and Eddy ;D

All CG checks are done with everting on,in the boat but fuel. Including paint and stickers!!

Measure the total lenght of your boat from sponson tip to transom. Leave the motor out of the mesurment.

I set my CGs at 27% from the transom forward. Remember that this is a good all around race CG. If heavy wind conditions make the water rough then you might want to move it back. But most of the time you do not move it forward from 27% point.

;Drimracer

 

[scoobydoo]

Grim,

Wouldn't you want to move the CG forward in rough & windy conditions ?? ??? ??? Please explain you logic on this one :- :-

 

[Grimracer]

Scoob

The last thing you want a tunnel boat to do is stuff. If you move the weight back (and I mean allot) the boat will just skip along on the rear edge. Its ugly but it does work.

Tunnel boats in rough water suck anyway so this is the best thing to do. You are not going to go fast anyway so you might as well finish.

Next time I give away a secret like this again, stop me..

By the way this is not a bunch of ca-ca it does work, try it!!

Grimracer

 

[TimD]

Scoobydoo,

What I do for rough windy conditions is apply more lead weight to the CG point of the hull. this makes the overall weight heavier but keeps the balance point the same( always double check the CG afterwards). On the old forum we discussed the effect of a light hulls tendency to blow over compared to a light one with a powerful piped engine out the back. I have done a fair amount of testing on this lately and you can get some very good results.

Tim.

 

[Kris Flynn]

hey all,

I design my own tunnels and i was wondering if anyone would be able to look at them to tell me if they would be any good??? :-

Thanks

Kris

 

[smokeyjoe859]

Bought a Top Speed tunnel about 2 years ago. It came with an OS .21 XM and a low end Futaba 2 channel. Finally got it together but now have to make alterations after reading the news section about this hull. Too bad I didn't run across this artical before I started. Anyway, does anyone know if those speed strips really help? They seem like a pain to install and I've never seen any other hulls with something like this on them. This is my 1st boat. Used to run with my brother's .21 glass hull but it was his (if you know what I mean). Any help is appreciated.

Thanx,

Smoke

 

[Ron Olson]

You can run it without them but they do add strength to the bottom to help with the flexing problem on this hull. You can put it close to the edge and fill in any gaps with body filler. Sand the inside edge so that it is sharp for best handling. The DPI hulls also come with these strips and is advised for other ABS tunnel hulls for the above reason.

 

[ggillman]

Kris,

I would be happy to look at your designs, you can

Email them to me at [email protected].

Smoke,

I ran the poop outa 2 Topspeed tunnnels, biggest flaw

was the radio box that came with it, Ron knows about that one too!!! Anyhow the speed strips help the hull to break away from the water and do add a measure of speed to the hull, Some guy's do the same thing with lite ply to the ABS Dumas Sprint hulls also, just take your time when installing the speedstrips on the Topspeed and get them straight, it makes a difference

and is worth the effort.

Gene ;D

 

[smokeyjoe859]

Thanx for the advice guys. The speed strips are going on. Another question: What is a good weight for this hull? After balancing it, it weighs in at around 5 lbs. on the bathroom scale. Seeing that it is all buttoned up, I'd hate to move anything. It was a pain to get the right CG. The origanal radio box seems stout enough and is sealed very well. But if lighter is better as in airplanes and the original radio box is junk, I'll build a new radio box and move the battery and RX foreward. What are your thoughts?

Thanx Again,

Smoke

 

[ggillman]

5lbs for a Topspeed with the OS outboard is about average weight for the stock configuration, lighter is not always better, the trick is to get the boat fast, but it still has to stay on the water. To lite and the boat will blow off at speed.

On the radio box and CG, if your hull is handleing good and your radio box is sealed and not flexing, (Both of mine were very flexy and did not seal well at all, the ABS was to thin, later models they may have changed) leave it alone and run it as is. The speed strips will get ya going a little faster, try some prop switching, Prather 215, Octura X440 work great on a Topspeed.

Gene ;D

 

[smokeyjoe859]

Thanx for all the advise! I'll leave it as is w/speed strips and give it a try. After the engine is broken in I'll do some prop swapping. I'll let you know how it goes. This is a great forum!!

Thanx Again,

Smoke