Top speed numbers

[08087]

Newbie here, I've been trying to find top speed numbers on ZAPCAT/DUX type boats with stock engines in the 40-70 hp range. I'm looking to replace a jet ski and top speed is one major factor in making up my mind.

Thanks in advance, please no guesses or inflated numbers.

08087

[Polwart]

Originally Posted by 08087

Thanks in advance, please no guesses or inflated numbers.

this is FIBnet - it is almost mandatory to do a bit of rounding! Top speed for a zapcat is going to vary depending on the seas it is in. The race courses are also often quite tight so I suspect they rarely spend much time at top speed.

This previous thread (Zapcat slow speed?????) says 43.1 knots with a standard 50HP tohatsu. Thats a smidgen under 50 mph or 80 kph if you prefer those units.

[9D280]

Welcome!

If it's top speed you are after, keep the weight down. There is a whole discussion about props lurking in the background, but suffice to say that Yam used to sell a series of smaller diameter props for speed. Theory was that the engine powwer not used to drag the big diameter blades through the water could be used to up the pitch (effectively higher gearing) and push the boat along faster. Only really worked with light boats, as a heavy boat needs "grip".

Having said that, a Zapcat weighs pretty much next to nothing, so you may be surprised what you could get away with in the HP dept......

What sort of speeds did you get from the jetski?

[rik_elliott]

43Mph on my cars gps on my zapcat with 40hp with a semi cleaver prop. Could have got more with a better balanced set up. It was quite fast enough though, hit a wave at that speed and youll certainly soil your wetsuit.
The girlfriend didnt enjoy it all that much tbh- there isnt a great deal to cling on to as a passenger. Id go to the australian thundercat forum if you need more info (google it)- they really know their sport and can give you a ton of tips for speed and props etc

[08087]

Thanks to all for the welcome and information.

My Jetski was able to get into the 50-52 mph range. It is a mid 90's modle yamaha w about 140 hp.

I can pick up many stock jet skis now that will get me to almost 70 MPH in stock form, they just don't have much fuel capacity/range at high speed. 15-18 gal. on most and @ 20 gph burn rate you are limited 2 an hour or 2 of fun befroe fillup.

I was looking toward a zapcat type boat for room, ability to carry extra gas can, ride as I would use it allot in a bay with sheltered waters. Much of the time you can run full out for several minutes at a time then you cut back to 35 or 40 until you reach the next segment of sheltered water.

How is the ride on these things? any better then a good jet ski? A jet ski nowa days comes in at 800 lbs or more.

The big problem with them is boaters don't like jetskiers as many gave themselves a bad name by coming too close to other boats trying to wake jump and other risky tricks. They have limited storage, you have to sit front/back and if you beach it and the tide goes out it could take a while to get it back in the water.

Looking to the zapcat as a good option, what do you all think? I'd like to go with a 70hp and get close to 70 MPH with a chopper prop. I just worry about it flipping on me if I don't have any lbs. in the front to hold it down.

[rik_elliott]

You can ballast the nose with a big fuel can full of water if going out alone. You are a braver man than I to be thinking putting 70hp on the back - you will need a steering damper if you intend on tiller control. Thought about a thunderbolt instead? They are about 5m so bigger and can get console controls etc.
The ride was very smooth on the cat but pretty wet. At full whack it did feel a bit flighty, but that was probably more my set up.

[Polwart]

Originally Posted by 08087

I was looking toward a zapcat type boat for room, ability to carry extra gas can, ride as I would use it allot in a bay with sheltered waters.

The big problem with them is boaters don't like jetskiers as many gave themselves a bad name by coming too close to other boats trying to wake jump and other risky tricks. They have limited storage, you have to sit front/back and if you beach it and the tide goes out it could take a while to get it back in the water.

Looking to the zapcat as a good option, what do you all think? I'd like to go with a 70hp and get close to 70 MPH with a chopper prop. I just worry about it flipping on me if I don't have any lbs. in the front to hold it down.

Firstly there's more to top speed than the "numbers"... although I realise that for some people its all about bragging rights in the bar - but I'd think unless you do stunts on a jetski then a zapcat might still give you similar thrills and spills.

However there isn't any real storage on deck either so its going to be dry bags and fuel cans bungeed down and bouncing around. If you want sensible "cruising" type luxuries a Zapcat is probably not the ideal boat.

I think 70HP would be stupid, especially with only 1 person on board. They race with 2 people and 50 HP and still flip them if they overcook it. I can't see what 70 HP will gain you except to say that on one perfect day you went faster than anyone else you know.

I wonder if anyone sells aquaquads over your way? They might be an option - a kind of cross between a Zapcat and a PWC or perhaps a ceasar surfcat which is somewhere between a Zapcat and a traditional Inflatable (or SIB as they are known round here) - which will do 50 mph.

[C-NUMB]

I think 50 hp is enough.....

YouTube - Worldrecord attempt 2007 thundercat crash

[08087]

Thanks for all the concern, it means a bunch!

I'm asking about a 70hp cause I see that some are rated for that power. If I understand it all correctly they much of the time run in the surf or ocean where it is churning up.

I can hit the Atlantic via the Little egg harbor inlet which is right by my house but we have a large bay with rivers that run for miles that are a great place for bird watching, fishing, crabbing, etc. Not to mention you can run full out with barely a ripple on the water most days as these rivers are not much more than a couple hundred feet wide at most points and have great snake turns in them! Loads of fun! I've just outgrown the 50+ speed of my jet ski and am ready to bump it up.

We have power boat races in these rivers which break 100 MPH every year, deep V's, Cat's, you name it!

I don't drink so I don't brag to my buddies at the bar, (I know there was no offense intended) I just enjoy the speed but being safe is also paramount on the list. I may go check out the other site recommended and ask around some, but the high end jet ski may be the route for me. 15K and 70 MPH is a bargain!

PS I'm at a cpu that I can't view YouTube but I will look into it later, thanks

[08087]

I just went on both aquaquads and ceasar surfcat and the aquacat is out, but the Ceasar cat looks like a good option but it does run expensive when you add a motor.

Thanks a bunch for the recommendations!