help in prop choices

[1987 175 mercury]

I have an 18.5 1987 Stratos VTROCKET bass boat with an 87 175 mercury.I will soon be beginning adjusting the set up of the boat.I am currently running an aftermarket turbo 2+2 4 blade prop.The boat jumps quickly on plane with very little bow lift and charges up to 5800 rpm's completely trimmed out and running around 60+.I feel this tunnel hull has much more performance in it.I have had great advice about a 24 pitch big ear chopper being cut down and running completely trimmed out for speed.In my mind I picture achieving the boats maximum performance without having to run completely trimmed out.Is there a prop that will give me the bow lift I need that will still give me the hole shot I need as well.Prop hub sizes or other prop adustments are there any other options available for me?Thanks.

 

[Bondo]

Re: help in prop choices

Is there a prop that will give me the bow lift I need that will still give me the hole shot I need as well.

Ayuh,... Possibly,...

Generally speakin', you give up low end for better Top end, or vice versa...

 

[1987 175 mercury]

Re: help in prop choices

Thanks for reply.What I will be trying to acomplish is getting the performance without having to trim out completely.

 

[kmarine]

Re: help in prop choices

By trimming out you are lifting part of the hull from the water to reduce drag to achieve max speed. To achieve better performance beyond what you are now expieriencing you may have to go to a prop shop where they will have demo props with different blade styles and cup varieties. after experimenting with a few styles you will need to record rpm with gps speed info at different speeds to select a final prop with your desired outcome. When racing we will change props regularly it is not only diameter and pitch, we also change blade shape and cup size. I recomend finding a shop that has prop scan.

 

[steelespike]

Re: help in prop choices

Why are you trying to limit trimming up?
There are props that will give maximum bow lift but they will likely slow hole shot
and make it harder to maintain minimum planing speed without constant throttle diddling.

 

[cyclops2]

Re: help in prop choices

Are you throwing a MASSIVELY HIGH & LONG rooster tail at maximum speed ? Have you reached the maximum of tilting your motor also ?

Who has a boat that YOU HAVE SEEN run faster than you. By how much with you holding YOUR hand held GPS in his boat ?

Most boats are slower when I ride in them with my GPS on.

 

[cyclops2]

Re: help in prop choices

Which prop did you buy TH or the OT ? Or did the boat come with it ?

 

[1987 175 mercury]

Re: help in prop choices

The reason I am trying to limit trimming out-When fully trimmed out is the time that handling issues could occur.Reaching full potential of the hull without fully trimmed out would be ideal.Probably not possible.Thanks.

 

[1987 175 mercury]

Re: help in prop choices

Yes I can reach full trim.The rooster tail is not massively huge.Big speed is nice but am going for overall performance.

 

[1987 175 mercury]

Re: help in prop choices

I dont understand your question about TH or OT.I bought the boat with an aftermarket 4 blade turbo 2+2.

 

[Faztbullet]

Re: help in prop choices

If you going to use the cut down like I suggested in other post you will need to learn to "fly" the hull at full trim,

 

[cyclops2]

Re: help in prop choices

I went to the prop website. TH means exhaust thru the hub. OH means over the hub exhaust. Also it states that your prop is to be FULLY SUBMERGED. That would include all turns.
Call the boat company & prop company.
Get some ROCK SOLID prop selection & how to trim the motor for that boat from the 2 companies.