My ballast epiphany

[shawndoggy]

1 hour ago, DarkSide said:

We were having a similar conversation while out this morning.   The person i was talking to works at Nautique dealer and rides for Soulcraft.

Certain board's are designed for bigger waves and don't perform as well on smaller waves.  Same thing boards that are designed for smaller waves tend to be too fast on larger waves with tons of push. 

I can ride smaller waves, but it is much more work.    Because i am larger, i need more push than a 135 pound pro rider.  

I thought this was an interesting blog post from BoardCo

 

http://www.mmwatersports.com/uncategorized/do-i-need-a-pro-level-wakesurf-wave/

Obviously it's different from the perspective of the author (being 6'6" and 300).  I actually make the wave "even smaller" for newbs.  Most of our newbs/guests are under 160 (kids).  I sometimes have a few larger adults (240ish) but that's like once a year.  For the smaller people, I find that a large / steep wave sends them right into the swim platform.  They seem to do better learning on a smaller / no wedge wave and then I add ballast and wedge from there.

I don't have any special boards -- my two board quiver is what I ride on everything.

[jhartt3]

interesting i may pull some weight out of mine and just list it a little more to the surf side. 

[mikeo]

I'm reviving an old thread because I've got some relevant information to share. I wanted to know exactly what I was pushing for ballast so I could make some informed decisions on what, if any, changes should be made. My first step was to determine exactly what I've got for ballast in my boat, so I called Malibu customer service, was transferred to tech support, and spent some time talking with Ron. Before I get to the numbers, I need to state that I don't count the weight of the ballast device in my calculations; I only count the volume of water weight. I don't remove my ballast tanks, bags, or other material from the boat so the weight of the container is a fixed quantity. I haven't calculated the weight of fuel or people in the boat (yet), but I might do that at some point in the future. I use the round number of 8.3 lbs per US gallon for the weight of water, I'm doubt the small amounts of minerals, dirt, etc. in the water will make the value change much.

For MY 2015 23 LSV (your build may be different) I had the stern tanks and center tank installed, I didn't have the bow tank installed because I wanted the storage space under the front seats. The hard tanks in my boat hold the following:

center tank: 58 US gallons, 481.4 lbs
rear port: 29 US gallons, 240.7 lbs
rear starboard: 25 US gallons, 207.5 lbs

I also run a Fly High W706 bow triangle, and 2x Eight.3 - plug 'n play - tapered ballast. I measured the volume of water that fits in my ballast when installed in my boat and I have the following results:
Fly High W706 bow triangle, rated 1000 lbs: 100 US gallons, 830 lbs (actual)
Eight.3 tapered ballast, rated 700 lbs: 65 US gallons, 539.5 lbs (actual) per side, 1079 lbs total*

Ron at Malibu shared with me that the testing Malibu has done shows that the best weight distribution is 60% stern, 40% bow. My configuration is:

Bow: 158 US gallons, 1311.4 lbs (bow triangle and center tank)
Stern: 184 US gallons, 1527.2 lbs (rear tanks and locker sacs)

This puts my configuration at 54% stern and 46% bow. I have some minor tweaking if I want to get to 60/40, but it's really close and I like the wake I have.

At this point my focus is going to shift to efficiency and engine wear; I feel that I'm running out of headroom on the throttle and I'm burning too much fuel. I've sent in my latest oil change sample to blackstone labs for analysis and I've got an electronic gauge hooked up so I can read fuel flow. I currently see 12-15 GPH when surfing at 10.6 MPH with a 2315 prop on my 230kW Indmar Monsoon "350" engine.

 * I found it odd that the "700 lbs" Eight.3 ballast only holds 65 US gallons for 539.5 lbs of ballast. This number is lower than the 550 lbs number published for the smaller bags. I've owned the 550 lbs bags previously, but didn't measure them when I had them and I'm sure the bags I have now are 700 lbs (labeled) and bigger than the 550 lbs bags I owned previously. I'm going to call Ronix/Eight.3 to ask them what's going on.

The most important sentence in all this information is "I like the wake I have" and that should be your goal too. I'm sharing info here, and my logic may be slightly different than yours. Find what works for you and go with it.