What strut do you i need

[jsu101]

I just got done building a whiplash 20 and was wondering what strut do i need? Or does it have to be like the sport 40 where the prop dog cant be past the back of the boat, Or can i use a rigger style.

 

[larcor69]

the drive dog can only extend beyond the transom 1 drive dog length or about 1/4" so the strut must exit through the bottom infront of the transom

 

[SayMikey]

the drive dog can only extend beyond the transom 1 drive dog length or about 1/4" so the strut must exit through the bottom infront of the transom

Wrong,in sport 20 the strut can be bolted to the rear of the transom setting it back 2 inches or so. Brian sets these boats up this way as do most sport 20 guys. Sportsman 20 Hydro (Sport 20 Hydro)

Boat Specifications

1. Boat must be inboard powered.

2. Hull must be a three (3) point hydroplane configuration and resemble a limited or

unlimited hydroplane design of past or present. Hulls not permitted: outrigger,

modified outrigger, tunnels, or canard hulls.

3. Boat must have a name, or sponsor's name, or logo, or a racing number affixed to the

hull. (a local or national or fictitious sponsor name is acceptable).

4. Hull shall have a minimum length of 27 inches, and a maximum length of 35 inches.

5. If the bow is recessed behind the tips of the sponsons, that recess shall be no larger

than 25% of the overall length of the boat. (refer to Sport Hull Configurations)

6. Boat must have a driver in open cockpit or simulated enclosed cockpit.

7. A strut width no greater than 9/16 inch wide may be mounted either under the hull

or on the transom with the farthest end of the drive dog, as measured from the

transom not extending out more than 3 inches.

8. See Sport Hull pictorial for clarification of Sport Hull Configurations

 

[larcor69]

what about sport 40??

 

[Dasboatman]

Hey Mike,

Nobody asked if he was planning on running IMPBA (which you referenced) or NAMBA sanctioned contests. NAMBA Sport 21 state:

"The propeller drive dog may be one drive dog length behind the transom of the boat"

So if jsu101 wants to be legal for both sanctioning bodies - - set it up with the strut underneath with The propeller drive dog may be one drive dog length behind the transom .

Ain't it GREAT to have so many choices!!! CHEERS !!! Bob Johnson

 

[larcor69]

so I was right in Namba, but incorrect as far a Impba!!, well that will let me off the hook as far as impba because I have a miss vegas with a .18 engine, everything was fine, as far as everyone letting me run in sport 20, in a Impba race till I was beating everyone with it, then they started complaining that my hull was not legal with the strut mounted past the transom!

 

[M@MRacing]

With the Miss Vegas to run in Namba as a sport20 you need the strut under the boat.

 

[jsu101]

Ok thanks guys

 

[larcor69]

but like i said, it was IMPBA