R12X Honda Hull Pictures

[supermac]

Pisonwash, these are for you.

[Green Hulk]

WOW! i see 3 things you can do to improve the speed of that craft.

Now i see why nobody has broken 70 yet.

1) that grate has got to go!
2) the pump inlet is too large. it's letting way too much water in (overstuff)
3) rideplate is waaaaay too flat. Weld some chines on it. This will create lift

Lets see what the guru pistonrash has to say

[01xdime]

That intake is HUGE!

[Green Hulk]

Yep! bigger is not better in this case

[RXP-REX]

I bet if we got some giant potatoes from Alaska, we could use that intake grate to slice some killer french fries.

Then we could throw some tomatoes and such through the pump to make some ketchup.

[Pistonwash]

Mac...a couple of things to experiment with:

1. Cut the #2 and #4 bars out of the intake grate..if you need details, just call..but they have to go. Leave #1, #3, #5 in place.

2. Reduce the size on the inlet gullet to at least GPR specs or close. I would try adding a half inch on each side, from front to rear with a gradual slope to the top of the intake gullet using a good fiberglass body filler.

3. Cut the end of the ride plate off..start with 1 inch and then go 1/4 inch every cut after that to see if the speed increases. If it begins to porpoise, stop. You can probably shim w/ washers from that point to get the ski to stop porpoising.

If that intake grate is hanging below the hull (check this by using a straight edge going across it) then you need to take the intake grate off and machine the rear of the surface that attaches to the hull, until it will recede higher into the hull, than the hull. It cannot hang below the hull.

I would also do one thing at a time..testing what it does before I move to the next modification. I would cut the bars off first and machine the rear of the grate fit first. then #2 would be to fill in the inlet gullett with filler to close to the 5 1/2 inch width.

Lastly I would work on the ride plate by cutting it off.

You will pick up speed somehwere with the forementioned changes.
If the inlet begins to starve for water, you can begin to widen it again by sanding the filler material off..but I would start out small then make it bigger.

Take copious notes on important data with a tachometer and gps..so you'll have baselines on your changes.

[Pale Rider]

Damn, that intake IS huge...
no woner why my friend dumped his Honda turbo for the RXP...PR...

[Pistonwash]

If that rideplate is'nt a heat exchanger..you might want to machine an angle in it towards the rear upwards, I would take out at least 2mm on the rear plate where the bolts are to get the negative angle up. This will loosen up the hull.

[RXP-REX]

If that intake grate is hanging below the hull (check this by using a straight edge going across it) then you need to take the intake grate off and machine the rear of the surface that attaches to the hull, until it will recede higher into the hull, than the hull. It cannot hang below the hull.

I know you don't want the intake grate to hang below the hull, but are you saying its ok to have it up in the hull a little? Like not flush with the hull, but up it in a little?

Rex Robinson

[Pistonwash]

Yes Rex..your goal is to step up everytime you have a surface going towards the rear of the ski. Nothing should ever hang down towards the rear..everything goes up all the way to the end of the rideplate. This something thats very important to the guys at Fountain racing according to their head mechanic Tommy Jordan.