Too Stroked

Center of balance is important in a boat and stern heavy boats cause some interesting problems. Yes, a 29' Fountain with the exact same power as a 27' Fountain (both singles) is faster and handles better. (I work for a Fountain dealer.) As for a 29' Fountain (w/ twins) compared to a 35' Fountain, same deal. And the 29' looks like it's going to sink by the stern at the dock. This has to do with both balance and a hydrodynamic formula having to do with beam vs length. If you keep the beam the same, adding length (to a point) adds speed.

Getting back to your Checkmate (which we also used to sell), twin 502s is a good deal of weight in the stern. Adding weight to the bow to balance it will help it handle much better, but may take a tick off the top end. But, if you want speed you can actually use, you may have to add ballast. Why do you think many race boats can add or remove ballast at the bow?

ezstriper

How fast is the boat now ? a friend of mine had a 29 fountain w/twin 454 efi's 80mph boat if you had the balls and all the planets were aligned..that boat with that much weight sounds like could be a handfull....

rgrgoog

iTrader: (3)

My 29 Fountain with my Supercharged 502s is on rails at 86-87 GPS mph. I have never run the boat un loaded and low on fuel but I am failry sure I could see 90+ before it got scary.

Too Stroked

Stepped (and which generation) or non-stepped though? The 28' Checkmate is a non-stepped deep V.

Oops, just saw you sig. If memory serves me correctly, '97 is either non-stepped or the very first generation with a single step. Yep, it sould run like it's on rails.

Inspector

iTrader: (1)

My Checkmate would run 80 on GPS when I purchased it all stock. The boat never handled well above @ 75 mph. It liked to chine walk on smooth water and the bow went skyward in rough water. I blamed some of this on the chincy drive gauges not giving an accurate reading of drive position and the rather small (12 X13.5) Insta Trim Tabs on the boat along with cable steering. I then updated the boat with stellings boxes, imco hyd steering 12 X 16 tab plates and engine improvements. The first time out with this combination the boat hit 83 on lake MI but was again chine walking and bouncing a lot. I only made one pass and the input shaft on one outdrive broke. This was the end of the season so the drive repair was completed over the winter. Also after the one trip out the transom was covered with soot so I contacted the person who updated the PCMs for the engine upgrades and was told to install adjustable fuel pressure regulators and set them to 36 psi. Over the winter I also added 30" labbed Bravo One props. The next year the boat never ran as fast as I expected which I believe was due to the fuel pressure being too low. Now I am going through the engines and plan to add the whipples for next year. I don’t like adding weight without function so I would prefer to relocate weight to balance the boat but do not know if there is enough benefit to justify the effort.

32hustlin

hey inspector have you tried swapping prop rotations i am having similar issues on my boat and also have the stellings boxes i went from spinning out to in and found that the boat had much better manners at speeds the nose stayed down instead of riding sky high i even picked up about 5 mph

rgrgoog

iTrader: (3)

Single step

audacity

u have a 28 foot boat with two big blocks sitting in the back of it. moving stuff around will not change your CG. people that think so have never actually taken CG measurements let alone know how to calculate them. changing the CG in a 40 foot boat is difficult to do! you will have to add weight to accomplish this. big changes in weight on a 40 foot boat results in moving the CG an inch!

the bottom of that checkmate is a mess like all other mass produced boats that are not blueprinted. you should focus a bit there.

many racers talk about changing CG when all they really did was change the moment of inertia. which they have no idea what that actually is or how it works.

to get your boat to run better(more stable at speed) you will have to do bottom work and add weight to it!

Inspector

iTrader: (1)

Where can I read about the hull blue printing process? Is there more too it than just making the running surface true / flat? Are the size and shape of the lifting strakes modified? Is there an ideal hull shape (convex vs. flat) on the running surface? I am interested in finding out more about this process.

Inspector

iTrader: (1)

I have planned on trying changing the prop rotations but never got around too it. Maybe next year if the engine work gets completed...