Prop advice

[Mike_G]

After first tests of a new SR-23
http://boatmad.com/forum/showthread.php?t=12445
I'm preparing next one for racing
It will have completly rebuild XR2 on 8 inch set back

First tests on Yamaha 200 ProV where made with my old 21inch Laser II prop
We where spinning 6100rpm running 68mph on gps unfortunetly I don't know what gear ratio this engine has. Boat felt extremly stable on this set up

I hope my XR2 will have much more power after rebuilding that this old yammer and it will be installed higher than yammer due to low water pick up

My question is what propeller should I try to put on XR2
Don't know if I should put cleaver or chopper. Know teoreticly the difference between those 2 props and don't know if chopper will be too dangerous for offshore begginer like me couse it makes huge bow lift force. However boat felt quite heavy with Laser II

So maybe I should use cleaver.....

but what size??? 23inch?? bigger??
are over hub really faster than thru hub?? does exhaust gases really help??

or maybe some other propeller??

Any sugestions and thoughts will be great

Mike

[FrenchPhil]

Mike, what does the hull weigh ?

[FrenchPhil]

The gear ratio is 1.86 which gives negative slip...

[Mike_G]

hull weights about 530 kg
engine 200kg
fuel 200kg

everything about 930kg

[Mike_G]

one more thing... my xr2 has 1:87 cle

[Mike_G]

Any one?? Any sugestions?? Please