31SS Sonic spinning IN???
 

I have a 31 with 525sc's spinning 4 blade 30 Bravo's. Every single Sonic I have seen has the props spinning out, yet most other boat manufacturer's spin their props IN to maximize top end speed. Has anyone tried swapping the drives on a 31 to spin in? If so, what were the results???

You do not need to swap the drives.

Go out with the props reversed and test, your shifters will be backwards but it will not harm anything, can make docking tough but not impossible.

If you like the results you can leave the props and change the cables on the controls. They are set up reverse of each other, swap the way they connect to the shifters and go.

Bravo drives are identical, the reversing is done with the controls.

My mechanic said the way the cables are set up on this boat a mere swap wouldnt work. Said it wasnt a major ordeal to swap the drives. Was just wondering if there are any gains to be made and if its worth the effort. may try running in reverse to test.

If you just swap the drives the shafts will spin the exact same way. Get a new mechanic. The direction is determined by which way the cable moves

+1

What he said. ^^^

ok, back to the original question. Regardless of what needs to be done to spin the props in, WILL IT MAKE A DIFFERENCE on top end? I want to hear from someone that has done it before I try it. I just find it odd that every single 31 Ive seen all spin out. I have friends with other boats and they all spin in.

For most boats in is faster, but can compromise handling and dock manners. I can't answer for a Sonic, but is it usually the rule.

From what I understand, spinning in is most beneficial to stepped and/or staggered boats. I tried it on my 31 with 496HO's and it made no difference in top speed or in docking. However, you have a lot more power. So, give the above mentioned method a try.

the boat presently gps' anywhere between 80.7 and 82.9 depending on load and conditions. I just want to squeeze a little more out of it before I have to resort to extension boxes and smaller pulleys on the blowers, lol

I tried spinning IN on my 30' Mystique with 500 EFI's, seemed to get on plane a little better, but top end was the same. Top end felt more stable with them spinning out. I keep them spinning out now.

My last boat was a 94 31ss with 502 efi's it ran 70.2 with my wife and i with 3/4 tank of fuel .I swapped the props one day just to see and we got 72 on gps .The ass end felt a little loose but not bad at all .Hope it helps i just swapped the props and ran in reverse for the day. Props were labbed 26 four bladdes
:boat:

With spinning them in what is a realistic gain 2-3 mph? I have thought about switching them to see if I pick up anything on the top end. I have whippled 500hp's and i am running in the low 90's gps. Best I have seen was 92.7. I think I am gonna try this and see if there is any benefit. Would nose cones help or hurt the switch?

Usually worth 2mph, much looser boat, worse docking. Nose cones would probably help with stability.

Make it easier on yourself and pull the center cushion on your rear bench seat and you will gain 2mph. I had a 1998 31ss with 525s running anywhere between 84-86mph

spinning in words should help the top end on all boats in good chop do to the fact that it helps give your boat more stern lift on flat water mabe not so much IMO

i would deff try thow

If you spin in... you will see a 2-3mph increase. However, you will notice more instability along with poor dockside handling. Not worth it in my case... I am happy where we are at... :)

Best day ever so far... http://imageshack.us/a/img140/452/dsc02665e.jpg

I spin the props out now just for the stability and dockside manners... pic shown was spinning in.

i dont think it is hard at all around the dock with them going in. its just an agistment u will have to get use to

Do you have a 31' SS or are you using your Donzi as a comparative subject? If you don't, take note that the X dim on the sonic, the hull degree along with configuration leads to "problems" while spinning inwards. Sure, you can get used to it but as stated, outward rotation is the easiest on this hull. Plus, specifically on my hull due to a raised X dim.

im using both i was looking to buy a 31 ss that was set up in. drove and docked good to me. but u r right about my 33 it is different. the 31 was a nice boat and would have bought it but the wife wanted a bigger cabin.