What speed will a 300XS give ?

[Gav]

Originally Posted by Tony Davis

Have you got product liability insurance Gav?

what black boat??????

[Tony Davis]

[sterling]

Friend of us have a Cyclone 21 with a 300XS,that boat runs 84 mph with a 28 bravo 1 labber,and I believe a 27 tempest is also close to 85.
The cyclone has a pad bottem,i don,t know what yours is having ? a true V ,or a modified V ?
And weight ? the Cyclone is around 400-450 kg bare.

I think you also can expect to see 84 mph .

sterling

[Gav]

Originally Posted by sterling

Friend of us have a Cyclone 21 with a 300XS,that boat runs 84 mph with a 28 bravo 1 labber,and I believe a 27 tempest is also close to 85.
The cyclone has a pad bottem,i don,t know what yours is having ? a true V ,or a modified V ?
And weight ? the Cyclone is around 400-450 kg bare.

I think you also can expect to see 84 mph .

sterling

the hull is a variable deadrise, with a vented notch, the keel length is about 17'6 but LOA is 21' , weight is about 450kg bare.

[Ph@ntastic]

Gav do you have any idea how she will handel at those speeds ?
If someone knows it must be you

By the way , this engine came of Sake's 27ft Revenger he is also a member here and a dear friend of mine !

[Gav]

Originally Posted by Ph@ntastic

Gav do you have any idea how she will handel at those speeds ?
If someone knows it must be you

I think it will be fine, she is a lot more stable at speed than similar sized boats, and requires very little work on the wheel making it a relaxing drive at speed. BUT i have only taken her to 71mph running a 24 chopper and she was a bit flighty but there was a bit of a chop on! with the ballistic 24 she ran a constant 68mph and felt steady as a rock! The sponsons/bustles extending off the transom have a lot to do with the stability and tends to correct the attitude of the boat when things start getting sloppy....

good luck and be careful.......

(if you need a test pilot......i'm available at very reasonable rates!)

[Ph@ntastic]

(if you need a test pilot......i'm available at very reasonable rates!) Youre the best mate

Thanks i will be catefull the first time i will take her out , i will keep you informed .
Anyone a idea on what prop to drive her ?

[Gav]

Originally Posted by Ph@ntastic

(
Anyone a idea on what prop to drive her ?

what shaft length is it 20"?
are you running the same height as the 200?

26" cleaver!

[Ph@ntastic]

Originally Posted by Gav

what shaft length is it 20"?
are you running the same height as the 200?

26" cleaver!

Yep same height as the 2.5L

[Ph@ntastic]

I went out today for the first time with the new engine , on a slight chopy water she go me to see 87,6 Mile / 141km/h @6000rpm with a 23p Mirage+ .
I will try the 22p Enertia next week hoping to get roud 6100/6200rpm and a litle more speed perhaps
I was out for about 2,5 hours cruising at wot 3500rpm and 4500rpm and she took 40L of euro98 in this time so i am a hapy man !

[Gav]

Originally Posted by Ph@ntastic

I went out today for the first time with the new engine , on a slight chopy water she go me to see 87,6 Mile / 141km/h @6000rpm with a 23p Mirage+ .
I will try the 22p Enertia next week hoping to get roud 6100/6200rpm and a litle more speed perhaps
I was out for about 2,5 hours cruising at wot 3500rpm and 4500rpm and she took 40L of euro98 in this time so i am a hapy man !

so Jurry how did the hull perform at that speed?

[Ph@ntastic]

Originally Posted by Gav

so Jurry how did the hull perform at that speed?

Beter then i ecpected , she runs verry smoothly truh copy water at wot !

[sterling]

Phantastic,are you sure the mirage is 23 pitch ?
Could it be a modified prop that has been tweaked to 27 or higher ?
The numbers do not match up with the prop you are turning at 6000 rpm,and 1,62:1 ratio,you should do theoretically 81 mph ,and with 10% slip around 73 mph,(if it is a 23 pitch)
Are you sure it wasn,t a 27 pitch mirage ?cause that would be the way to achieve those speeds,at 6000 rpm with 1,62:1 in the box.

sterling

[Jon Fuller]

6000 (rpm) divide by 1.62:1 = 3703 x 23 ("pitch) = 85185 divide by 1056 (magic number) = 80.66 (mph before slip) x 0.9 (10% slip factor) = 72.6mph (actual speed, assuming pitch and tachometer are correct)

EDIT> looks like Sterling beat me to it!

[Gav]

Originally Posted by sterling

Phantastic,are you sure the mirage is 23 pitch ?
Could it be a modified prop that has been tweaked to 27 or higher ?
The numbers do not match up with the prop you are turning at 6000 rpm,and 1,62:1 ratio,you should do theoretically 81 mph ,and with 10% slip around 73 mph,(if it is a 23 pitch)
Are you sure it wasn,t a 27 pitch mirage ?cause that would be the way to achieve those speeds,at 6000 rpm with 1,62:1 in the box.

sterling

sterling, there maybe a possibilty that the 600xs hull design means a much lower slip factor, when i ran the boat with a 200 @ 68.9mph the numbers were suggesting a slip of around 5%.

[Burty]

that still aint 87mph though is it

[sterling]

Its possible Gav ,I,ve seen it before some boats do have a lower slipfactor.

But generally 10 % is a perfect number ,What I see more on boats like this is a 12% slip factor.

John,guess I was pretty quick huh

[Ph@ntastic]

Steling , i am positive it is a 23p it came new out of the box .
I have no idea what hapend but the readings are there i there were withnesses .

Although i heard someting about props that were printed withe the wrong pitch on it last week at Bonestroo .

[Gav]

Originally Posted by sterling

Its possible Gav ,I,ve seen it before some boats do have a lower slipfactor.

But generally 10 % is a perfect number ,What I see more on boats like this is a 12% slip factor.

agreed in the norm 10% - 12% is about right ........ but i am convinced the 600 is a lot lower. just IMHO of course

[roofer]

With a 23 prop the engine should have been bouncing on the limiter, with that much torque you should be able to swing a big pitch prop.