gofast53

Boat is heavy on left side due to header and pipe. Tank is mounted in centre of hull and would be difficult to move as is a weedeater type with screw cap.
Remounted trim tabs 1/4" up from bottom of hull (see picture) as suggested and also folded plate ends up, will be interesting to see if any improvement in handling.
Took some measurements and rear engine mounts (nearest drive coupler) are 16" from transom with CG at 15" from transom. Based on total hull length (excluding hardware) of 47" this makes my CG at 32%.

stevblutu15

if you want an even boat- i mean if your racing you could move the tank to the right side- this would level you out a bit- if not racing just adjust the trim tabs to run level- thats what theyre there for. I included some images of my setup for comparison- just trying to help you out-

Steve

Roxyflash

I dont like the hooked water pickup running that low could be like a anchor causing drag.Could you get by with the rudder pickup only?Is the skeg staying in the water in the corners?I had mine that was alittle short causing some issues it would come out of the water at times so i mde it deeper.

gofast53

Thanks for the advise guys...boat was originally set up by someone else so any suggested changes to improve performance is appreciated. In regards to water pickup I have not tried using rudder pickup only will try and see how hot engine and pipe run. Have no problem with skeg leaving the water!
Adjusting trim tabs to run boat level, is this done by leaving right side plates level and angling left side (heavy side of boat) slightly downwards to lift hull up so that it is running level on water? Also my plates are split (two plates per side) and have read in other forums that the outer plate on either side controls ride of boat when cornering and that the inners plates (nearest prop shaft) control ride of boat in a straight.... is this true. If not then why have them split?
Do not want to start relocating tank to balance boat out if I can help it.

Roxyflash

Could add weight to balance it side to side

stevblutu15

cant help you with the split but yes lower the left to make it run level

dicko

Sorry to dig up an old thread, but thought it'd be better than starting another one.

Question - How big are the Skegs you run on your crackerbox?
Also, what is the best prop for a stock Zenoah? any mods on the prop?

hosnoopy

My new cracker turns very well my Skeg is offset to the left stringer (Shark Fin 50mm deep) and a large turn fin ..... My COG is at 34% slow in smooth water but comes alive in the chop when others are flipping

dicko

Thanks,

I got some plans from Tony at Warehouse Hobbies, it's about 2.5 inches tall, narrowing from base to tip. The hull I'll be putting it on isn't a conventional hull, it's a stepped vee to rounded stern (pic below). The skeg will be just behind the step, so the deeper skeg will probably be better.

any idea on what prop is a good one to start with? it'll be going on a stinger strut (surface drive), not the type usually used on a crackerbox.

martno1fan

Try a prather 275 prop for a stock zenoah,im currently using an ali prop on my new boat its 78 mm and runs well on that .not a cbox but the 275 or similar size seems to be the prop of choice for a stock zenoah.

dicko

If anyone has the WHH 1/4 scale driver figures could they let me know the dimensions of the base? I have some in the post, but need to know how wide they are & how long they are so I can start building the hatch they will be mounted too.

Cheers
Jason

dicko

nevermind, they just arrived. Now I have got some painting & gluing to do.