slip on 5 - 6 blades
 

How do you figure slip on five & six blade props.. same? or go up or down in pitch? what slip % do you shoot for with each?

Re: slip on 5 - 6 blades
 

If they are Hydromotive or Hering props they are true to pitch. So use the pitch marked on the prop.

Julie

Re: slip on 5 - 6 blades
 

Slip is slip. So yes you figure it the same.

The boat you are setting up determines what % you shoot for.

As a general rule.........under 15% for sport applications and under 10% for race set ups.

Re: slip on 5 - 6 blades
 

It depends on the boat as far as the target slip %. Cats are going to have lower slip than V bottoms.

For example a Donzi 38 ZR with 5 blade props and staggered motors should have a slip of about 9-10%. While a 36 Skater with 6 blades should have a slip of 3-4%.

Julie

Re: slip on 5 - 6 blades
 

my 38 donzi ZR is @ 8.11 slip with the Hering 31p 5 blade @ 5300 rpm. 95.3 mph what would happen if i went with a 1" shorty imco lower... will rpm go up to around 5450 + speed? or more slip + less speed? it has standard xr its. Thanks for your thoughts Jeff

Re: slip on 5 - 6 blades
 

also Jim told me the 6 blade is down to 6% slip... but i must go down to 1 in pitch (30P) in theory its slower that the 5 blade (31p) @ 8% slip?

Re: slip on 5 - 6 blades
 

You have a great set up. When we were working with the Donzi factory F2 and Super V teams the 6 blade props were just starting to come out so we didn't work with those props on the race boats. Typically from some of the other Donzi race teams expect to see top speed about the same with either the 5 or 6 blade props. The 6 blade props typically yield better acceleration than the 5 blade props, that's why they are so popular with race boats.

Your speed isn't bad for your boat. 1" shorties may be a good idea and may give you a little more on the top end. Before you start changing lowers and props I would suggest calling someone at Donzi we work very closely with. He knows the Donzi's better than anyone and was the crew chief for all the factory race teams. I am sure he would be more than happy to give you some tips about what might give you a little more top end without spending a lot of money on lowers and props right now.

If you are interested in talking with him give us a PM or call and I will give you his contact information.

Matt