Prop rotation
 

Any ideas about propeller rotation?The boat is a 38KV with notched transom and high X-dim.I have been forced to spin my props inwards because of incredible poor hole shot with Mirage plus.But I will replace them for Bravo 1 (4 blade) this year,and think that problem is gone.Most of my friends twin engine V-hulls are spinning their props outwards.What can I expect by swaping the drives.Bowlift,handling,top end,etc?

Thanks in advance.

If you have bravo drives - swaping the drives wont change the prop rotation.
How you change prop rotation when you have bravos is to just change the props and then change the shift cables at the shifters.
If you just want to test - just change the props over and pull the shifters into reverse to go forward.
BE REAL CAREFULL DOCKING

I have TRS. Thats why I'm asking this question.It takes a lot more job to "just test".I want some opinions before I start.

My boat is 38 KV also. Not a notched transom, or aggressive x-dimension. I am spinning props inward tho with Bravo 1 four blade 24 pitch. I plan on going to a 22 because my motors aren't turning more than 4600rpm's and that's trimmed out. The hole shot with the 24's isn't to bad. I never even touch the trim tabs and it usually pops right up, but I am carefull coming on plain, since I blew a drive coming out of the hole two summer ago.
Good luck!

OBNOXUS21,Have you tried to spin your props in opposite rotation(out)?What I want to know is the difference in overall boat behaving.I am convinced that I get better hole shot and less slip (28%)with my new props .I think 22" is perfect for you OBNOXUS21. I had mirage+25"on the boat last spring and also 4600 on the tachs,I changed to 23"and turned 5000 and gained 4 mph!So I am also going for bravo 22" this year.But,can I improve performance by changing prop rotation?

From what I have read and been told, spinning the props inward should increase the performance of the boat. I know you said most people with twins you've seen have there's spinning out, but most I have seen have theres spinning inward.
What knid of power are you running? I am running 468 cu.in. 500hp's. I was also told I should gain about 4-5 mph with the different props. I guess it's time to start shopping :p

BTW, I just realized that you are in Sweden!!! I am in Nederland!!! I will be here until Mid to late April. I spoke with some people in Denmark that said there are some nice boats there!! I want to get around if it is warm enough before I leave and meet some OSOer's from here in Europe. Especially if one has as good of taste in POWERboats as I do ;) :D :D

Hope that helps,
Justin

Hey guys ... do a search on this topic...it has been talked about alot...... Dave... on TRS drives you have to physicaly switch drives... pretty easy though....

That's right Justin,I am in Sweden. I really hope we can meet before you are leaving Europe,I think we have a lot to talk about:D

I am running 454cui/420hp's, but going for 8-71's and stellings next year. Very strange that most of you in the US are spinning your props inward,when they are out here in Sweden.That makes me even more confused.

I guess I have to testdrive the boat as it is,switch the drives and take it for a new ride to really find out:( ... But if some of you guys have experiences in this case,please let me know.:)

Thanks for the info so far,
Jonas

Just to be shure we don't missunderstand eachother.This is what I mean "inward"(Picture of my drives)

For what it is worth my 29 has them spinning out. Also my friends 33 outlaw has them spinning out.

I have been around the powerboat sites at the web looking for pic's and it seems like 98% are spinning out :confused:
tssteph,I can't see your pic(I'm not a goldmember yet).But I suppose it shows the opposite rotation compared to mine. Is it anyone out there who had tried both directions at the same boat?:crazy:

Right hand engine prop is spinning clockwise from the rear of the boat. I assume this is spinning out. I just got the boat so I have not tinkered with anything yet. My understanding is that if mine was switched then handling is a issue but speed will increase.

"Handling an issue but speed will increase." That is also the type of things I have heard. I cannot verify that myself as i have never switched before. Eitherway, my boat handles very well and is predictable.

38KV---Try posting this topic in the "Technical Q.&A." section or the "General Discussion Section." I know you will get a much broader audience and more knowledgable people than myself. Outherwise, just do the switch and feel it out for yourself!!! I think you only need to switch the lowers?

BTW...
When do you usually "wake the baby" for spring time? I would like to plan a long weekend out you way before I leave. I had planned on visiting Sweden anyway and what better way than boating ;) :D :p

OBNOXUS,It is unfortunately too cold here for powerboating before early may,but I'll give you a "garagetour"when you arrive.
If you try to come here as late as possible before you're leaving Europe there is a chance some cool rides are "wet".
Send me an email before you're planning to show up.

Posting a pic of my "baby" to tempt you come here:D :D :D

Props spinning IN creates more bow lift (props tend to pull the transom down) and thus is usually faster top end due to less wetted surface. You lose docking manuverability and some stability at speed. Props spinning OUT (props tend to raise the transom) usually makes the boat handle better around the dock and at speed (more wetted surface) on most boats. This is a general rule of thumb. There are many set up factors (weight distribution, hull steps, staggered engines, X dimension, etc) that could alter these results.
Try as many combinations as you can and see what works best for your needs and your particular boat. That's what is fun about boating. Good luck.

OBNOXUS21, When you say spinning the props in gives more "performance," please clarify. It gives more "speed," but you often loose handling.

For example, I blew forward in one of my drives in the middle of the Florida Keys, so for a quick fix, I switched the props and put the shifters in reverse, which now made me go forward. Switching the props from spinning out to spinning in caused my 38 AVS to drive like I was on ice/grease -- but it got me back on two motors rather than one.