Top Heavy Tunnel Hull ? -Video-

**CUDA** · 07-04-2019, 06:42 AM

The only thing top heavy is the driver

Now get your sawzall cut open the deck 12 to 18" and move the driver forward.

**home made tunnel** · 07-05-2019, 02:37 PM

Yes - I think I'm going to grab a few bags of sand and throw them up front. Maybe 200lbs and see what she does.

**home made tunnel** · 07-05-2019, 02:41 PM

Originally Posted by CUDA

The only thing top heavy is the driver

Now get your sawzall cut open the deck 12 to 18" and move the driver forward.

Don't tempt me! haha. I'm THIS close to removing the gas tank in back, and doing something up forward, but it will be a smaller tank for sure. Not much room up there. Just getting the battery up there was a pain in the arse. Right now I have an 18 gallon tank in the rear hatch. I don't think that's helping anything.
I'll run the tank low, and throw some sandbags up front. Maybe i'll do a fuel bladder type system. That's about the only way I could get a tank up there.

**Captaincj** · 07-06-2019, 11:45 AM

Originally Posted by home made tunnel

Yes - I think I'm going to grab a few bags of sand and throw them up front. Maybe 200lbs and see what she does.

I think 200lb is probably too much, especially if you move them way up front. Start with less and add more as needed.

Maybe don't have to change or move fuel tank, just don't fill it up all the way. Wouldn't want the tank up front anyway as your balance and hop would always be changing depending on how much fuel you've burned.

Oh the fun of custom design/rigging.

**Captaincj** · 07-06-2019, 12:03 PM

I bought this bag recently to use for ballast for my side-steer Viking:

https://smile.amazon.com/dp/B0752S2F...roduct_details

It fits a 50lb playsand bag from Ace hardware perfectly. The bag of playsand is brick shaped so doesn't roll around.

Has been great so far.

**carb a rator** · 07-08-2019, 10:42 AM

Something you could try is put the boat in a slight left arc and see if it stays planted. On mine i did that untill i fixed it. My problem was the center pod was too high, even with the sponsons. I know yours is a true tunnel but maybe engine height, if not weight distribution is probably the issue. The weight up front should tell you some things, and you can fix it from there. Good luck.

**Davidlake** · 07-08-2019, 11:45 AM

Originally Posted by home made tunnel

Yes - I think I'm going to grab a few bags of sand and throw them up front. Maybe 200lbs and see what she does.

200# is definitely too much! When in real rough water, I.E. LOTO, I add 70# up front in my 28 Skater. Works well.

**CUDA** · 07-08-2019, 11:49 AM

That's an idea, Hydrostream would have a small ramp near transom to push down front.
Try easy stuff first.

**David - WI** · 07-08-2019, 01:05 PM

You might want to consider Jim Russell's Tunnelboat Design program before you start moving fuel tanks and cutting up your hull. It takes a little time to enter all your weights & dimensions in... but after that you can try any changes you want and see the results in seconds.

https://aeromarineresearch.com/tbdp6.html

**home made tunnel** · 07-08-2019, 03:06 PM

Originally Posted by David - WI

You might want to consider Jim Russell's Tunnelboat Design program before you start moving fuel tanks and cutting up your hull. It takes a little time to enter all your weights & dimensions in... but after that you can try any changes you want and see the results in seconds.

https://aeromarineresearch.com/tbdp6.html

WOW!!! $400 for the program!!! I'd consider it if it was like $40, but dang that's a price gouge for a computer program.

I'm going to try the sand bags this week first.

**home made tunnel** · 07-08-2019, 03:10 PM

Originally Posted by CUDA

That's an idea that Hydrostream would have a small ramp new transom to push down front.
Thy easy stuff first.

Don't they call this "Hook" ? I thought most guys eliminate the hook when re-doing their boats?
Mine has a pad on the bottom of each sponson, but they're flat.

**XstreamVking** · 07-08-2019, 03:17 PM

A lot or people do eliminate the hook and end up with a porpoise....That you can't ride. Tunnels typically use compression of the tunnel itself to accomplish the same thing. To provide stern lift.

**David - WI** · 07-08-2019, 04:09 PM

Originally Posted by home made tunnel

WOW!!! $400 for the program!!! I'd consider it if it was like $40, but dang that's a price gouge for a computer program.

I'm going to try the sand bags this week first.

$400 is a bargain, but you can do it the hard way, too. LOL

**CUDA** · 07-08-2019, 05:39 PM

I'm just talking about making a 3/16 high 1 inch wide strip of Bondo at the end of the running surface / sponson. easy to sand off or lower if too much.

Allison's use a low lip

**home made tunnel** · 07-08-2019, 06:21 PM

Originally Posted by David - WI

$400 is a bargain, but you can do it the hard way, too. LOL

You buy it, i'll give you all my measurements LOL :^P
I'm a single income family man over here saving to build a house next year for wifey and 2 daughters haha.