Ya ever wonder.....

[Slideblues]

Where I get all my tunnel mod ideas....

Look close at a Champ tunnel at speed:

 

[waterbug]

Gene

I noticed that last night !! also do you notice the crown on the upper center section ?? Now pan back to the second boat, it appears not to have the center piece down the middle. But has all the other features.

Thats what I was talking about when I asked my questions . Seemes like anything you can do to push the air down at the rear would help lighten the weight on the transom . I suspect they are doing the center section that way to keep the rear of the boat from settling down too much in the turns and the lift down the straight ??

WOULDN'T YOU LIKE TO BE IN THAT SEAT !!!!!

 

[Slideblues]

Yeah, the biggest thing to me was that the angle remained the same from the outside sponson edge across the center section inward to the cowling, not the usuall drop down. Hmmmmmmmm.......

Gene ;D

 

[Jeff Torgalski]

Darnit, will you guys stop? Now how am I supposed to come up with an idea I can call "my own" with all of you thinking so much?

 

[Slideblues]

Jeff,

Its a disease Man, "The Mod Flu" 8)

Gene ;D

Hey if you try out any of the above let me know how it works

 

[GTR]

Hi Guy's,

I will have to post some pics of my 7.5 tunnel. Has most of these ideas already incorporated in it - handles rough water really well. It doesn't look, or is proportioned like the usual tunnels.

I will post some pics so you can see what I mean.

cheers

GT 8)

 

[Slideblues]

Hey GT,

You bet cha I wanna see some pics

I like the different stuff!!!!

Gene ;D

 

[waterbug]

It's a good thing they screwed up on my large wood order !!! and UPS sent it back !!! DA !! Or I would only have a bunch of parts of boats ;D

Gene how about a COF hull ?? Carbon Over Foam !!

 

[Slideblues]

Hmmmmmm......

Yeah its possible,

Hey does anyone make a CF tunnel, other than that Proteus one from a few years back, a more conventional design?

Gene ;D

 

[TimD]

Gene,

we have made a CF F1-11 but it was too heavy. (it wasn't bagged)

We just use glass (chopped strand mat) and put CF cloth on the "weak spots" for reinforcment. It is very hard to get CF cloth into corners of molds properly.

 

[GTR]

Hi Gene,

Keep trying to post these but it times out with a fatal. >

Hope it works now

GT

 

[GTR]

Hi Gene

It worked but only in email size

GT

 

[GTR]

Another

 

[GTR]

And another

 

[GTR]

Last one ;D

Yee-haa

GT 8)

 

[Slideblues]

Hey GT,

Man you were not kiddin, that is close to the Champ hull, Excellent Dude!!!!!

Its called a Viper? Is it made in Oz?

Gene ;D

 

[GTR]

Hi Gene,

I thought it was a Viper (made in Oz) but I have since found out it isn't, Unfortunately don't know what it is other than where the previous owner brought it from. I'll post some dimensions to give you an idea about how different it is from standard model tunnel designs.

GT

 

[Slideblues]

Yeah some measurements would be Kewl, tunnel width and depth at sponson bottom and width at the runners

is very usefull

Gene ;D

 

[Jimboat]

Slideblues - you sure have an eye for design features... fun stuff, isn't it!

1. That inside runner is called a 'lift strake' or 'spray rail'. Lot's of controversy in design circles re: it's value. The placement height of the spray rail is very important to it's functionality, and proper location can really help to 'pop' after setting hull in corner, and can prevent over-wetting at lower speeds.

2. The vertical fin or 'fence' is intended to act to prevent air spillage or 'wing-tip' vortices that contribute to aerodynamic drag. I am not always convinced that the fences save more drag than they create, as they can often heavily disturb the laminar flow of air over the main 'wing' section of the tunnel.

3. The drop in the tunnel roof (floor) was initiated in the 1980's to lower the height of the driver, resulting in a lower center of gravity and a reduced bluff area presented for aerodynamic drag. Advancements in mod-vp style hull designs proved the potential contribution of hydrodynamic lift from this center 'sponson', and it became more prominant. They can now be designed to aid substantially in acceleration through lower velocities and recovery out of turns.

4. The full length strake (outside) has the same benefits as the 'spray rail' on the inside tunnel. Location height is really important.

5. The 'flat' center section is a much more efficient aerodynamic lifting surface design. (Look at aeroplane wings...they are all 'flat' throughout the wingspan, right?) The 'flat' design isn't used by many designers as much as it could though, 'cause it often doesn't look as 'cool'.

6. Lower frontal area - less is always more! Less frontal 'bluff' area generates much less aerodynamic drag, particularly at higher velocities. A one (1) sq. ft. area produces 4 times as much drag at 60mph as it does at 30 mph. Less is better, and streamlined airflow design is even better.

Fun stuff, isn't it. I love it!

/Jimboat

Secrets of Tunnel Boat Design

 

[Slideblues]

Hey JimB,

Thank you for all the info, that's very helpfull.

Yes it is fun to pick out all the design differences from hull to hull, Man they are changin, The Champ hull's are just amazing, that much HP and speed!!!!

Cool Stuff

Gene ;D