Bottom work to increase speed
 

I know most if not all of the F-1 teams out there have their hulls "worked" for more speed. Does anyone know what this consists of? Who does it? Cost ? Etc.? I have a 29 Warlock with a whippled 502 running 79.5 mph gps and just want that extra coupe MPH:D

Run a gallon of fuel lighter ;)

Not sure what F1 teams do, but I do know that you can get it blue printed to the manufactures specs.

Flip her upside down, take a straightedge and check the hull for hook or rocker. Check with the mfr to see if it is SUPPOSED to have hook or rocker (some weird outboard hulls work well with such - 'streams all have rocker, and Allisons have a hook-like turndown - don't take these out).

Assuming your hull does not have a weird contour designed into it, start filling the low spots and sanding down the high spots. Make 'er FLAT and STRAIGHT. Add filler material on the corners of the strakes and back edge of the transom. Keep those corners as sharp as possible.

When finished, prime and seal, then wetsand. All done!

Koko,
Mc is right. you can get gel coat and mix it with cabosil (ground fiberglass) and it makes a paste. I used a piece of 1' alum angle iron folded a piece of wax paper to fit, mixed the gel coat and poured it into the wax lined angle iron and then pressed it up to the rounded corners of the chine, strakes, backs of the steps and transom. It works great and most of the sanding is eliminated and your starting with a square corner! getting the bottom "straight" is tougher. I bought long aluminum rulers and fastened angle iron to them for rigidity, 2,4,6,8'. I still use them for other things too . Hold a light up behind the ruler and you can see concave spots. outline them with a black marker rough them up and acetone wipe and apply gelcoat. always cover with wax paper to help it cure to the surface and reduce balling up of the sandpaper. I'm going to do my eliminator this year in the fall 1 step at a time to monitor the results. Any questions you can call me or PM 815-218-1603 Greg

You may also concider doing just the actual running surface the back however many feet that is actualy in the water at speed. Should save time and money unless you want better no wake performance:rolleyes:
I would think the addition of sharp trailing edges would be a plus. The water will leave the hull and not wrap around the curved edge.

This is what is referred to as "Blue-printing" the bottom. Basically, it involves taking long straight edge to running surface. From there it's just sanding to improve straightness,add gel to low spots,etc.any hooks or rockers that are suppose to be there, if eliminated can/will change handling. In addition, the edges of strakes are typically sharpened up. Cost depends on how bad your bottom is to start with, as well as the size of the boat. Typically only the wetted running surface is worked. Results will depend on how bad the bottom is to start with. I had mine done last year.....no gain. but, bottom was pretty good from factory. Another guy had his Scarab done, picked up 5 MPH.

Where were you guys and OSO a few years back?? I had to learn all that stuff the hard way. Great advice! But I just love the casual way you say "flip her upside down". The stripping and flipping is the worst of the job. Anyone know of a good compound that is proven to stick if applied upside down or on the verticle if the hull were rolled on it's side? This would make these upgrades much more do-able for the "facility impared". Thanks --- Jer

If the hook is right at the transom, is that just built up fiberglass that can be sanded off?

be careful with taking out a hook. one like that might be there from the factory for a reason. I would make sure you check with the factory befor removing anything from the hull. you dont want to make a big mistake .

see HBs comment.
Check w/ the porters' tech guys.

Without seeing the straightness "trend" from about 8' forward of the transom back to it, it is hard to tell what part is "curved" and what part has a "kickdown" to it.

Even if you opt to keep the kickdown (if that's truly what it is) then you can still benefit from sharpening the back edges of the strakes and transom.

I have a long castiron straightedge that is 2" wide on the base and weighs 80 or 90 pounds. I use 3M self stick sandpaper on it and it does a wonderful job. I cannot IMAGINE using this bastage upside down from the underside.

I've never done a sterndrive boat hull. Only outboard raceboats. they weren't very hard to flip over. Don't know what the best answer would be for a big 35'er.

Maybe you could get bunch of kids to sand on it from the bottom if you feed them lots of those Tony's Pizza Rolls (it works for that kid in the commercial for his yardwork).