SIB Trim & Performance

[Steve509926]

I have always thought that the set up/trim I had in Redneck was pretty much at its optimum, two up, dog in the middle. Two lightish dry bags at the stern, builders bucket with the usual in & 15 ltr fuel at the bow. Yesterday proved that not to be the case The sea was very choppy at times and Diane wanted to sit on the deck, so I moved the 15 ltrs fuel to the stern to give her more room. When the sea had calmed down, I left it exactly as it was, opened up Redneck and noticed a distinct improvement in performance and speed. On the plane the same, but handled much better and increased speed by 1.2knts.
I wonder if the 5hp extra power moving from a 15 to a 20 could change the trim needed?

[jeffstevens763@g]

Originally Posted by Steve509926

I have always thought that the set up/trim I had in Redneck was pretty much at its optimum, two up, dog in the middle. Two lightish dry bags at the stern, builders bucket with the usual in & 15 ltr fuel at the bow. Yesterday proved that not to be the case The sea was very choppy at times and Diane wanted to sit on the deck, so I moved the 15 ltrs fuel to the stern to give her more room. When the sea had calmed down, I left it exactly as it was, opened up Redneck and noticed a distinct improvement in performance and speed. On the plane the same, but handled much better and increased speed by 1.2knts.
I wonder if the 5hp extra power moving from a 15 to a 20 could change the trim needed?

Sounds like you were bow heavy giving some drag, I always like to see my boats attitude when out camping as on this last trip then I know I have kit balanced right. In my experience 5hp gives around 2 knots more at WOT but it also gives more scope to down pitch for a crisper performance in the chop when getting back on the plane again plus a better cruising speed.

[paddlers]

I changed from a 15 hp 2 stroke Mercury to a 20 hp 4 stroke Tohatsu ( much heavier) and the improvement in performance was pretty dramatic .
It was on a 3.5 AE Honwave and the extra 5 hp really got it moving.

[Steve509926]

Originally Posted by paddlers

I changed from a 15 hp 2 stroke Mercury to a 20 hp 4 stroke Tohatsu ( much heavier) and the improvement in performance was pretty dramatic .
It was on a 3.5 AE Honwave and the extra 5 hp really got it moving.

It's not so much the extra hp I was meaning, it's the shift in weight/trimming the SIB better which has given better performance and handling with the same hp.

[paddlers]

Originally Posted by Steve509926

It's not so much the extra hp I was meaning, it's the shift in weight/trimming the SIB better which has given better performance and handling with the same hp.

I get that but I certainly found the trim and weight distribution much less critical with the extra hp .Popped up onto the plane quicker and stayed there but I must confess I never checked the propellers both of which were factory originals.

[Steve509926]

I've checked both the OE and Polarstorm 9.25 props, OE is running bang on 6300 rpm and the Polarstorm is running at 6275. So not a lot in it.