SBH2OMan
Well-known member
OK boys and girls... The Honda just had its 20-hour initial service and while it was out of the water, I had the shop install a new Perma-Trim unit (Andy recommended the "under-the-plate" type).
After about an hour on the water with the Perma-Trim, I have a bunch of data about speed and RPM both before and after the Perma-Trim, and honestly, there is not a big difference in terms of optimum performance. The big difference I see so far is that prior to the Perma-Trim, the boat required full tabs to get up on plane easily, whereas tabs are no longer needed at all to get up quickly onto plane. All testing so far has been done with 3/4 tank of gas and one person (light load). Heavier loads will probably demonstrate a greater benefit of the Perma-Trim in terms of getting on plane.
The boat is now more sensitive to engine trim, and this seems to make the difference. She comes up on plane smoothly and quickly now, but still doesn't truly plane out (stern completely up and bracket not dragging & throwing spray) until about 20-22 mph unless I give her a lot of tabs, which makes her very inefficient obviously. The boat is also now more sensitive to side-to-side trim, so I have to be more careful with the tabs, depending on sea state and course.
Bottom line, the Perma-Trim did not have a dramatic impact (good or bad), but did make it so that I don't have to fiddle with the trim tabs while coming up on plane, and I consider that a benefit worth the price. I can now leave the tabs retracted (all the way "up" or "bow up") and use the engine trim (down) to push the bow down into the sea while coming up on plane. Then depending on sea state, I can trim the motor up a bit for more efficiency. The other effect of the Perma-Trim is that the transition from plowing to planing is very gradual and smooth now - you can't feel a sudden transition like you use to feel with my old motor and prior to the Perma-Trim.
I think I can still get better performance by playing around with the prop and engine height, but I'm going to spend more time with the current setup before I make a decision. I think a 15" Mirage or Enertia prop would be beter and also give better cruising speed than the current Solas 13 prop. Cruising speed now is probably around 22-25 mph (for best economy) which is about 4200-4500 rpm depending on sea state.
I did notice that WOT used to peg out at 6,000 rpm (rev limiter) before the Perma-Trim, but now seems to stop at around 5800 or 5900, so there is apparently some loss of top end, but it may have been that I had the engine trimmed down too far.
After about an hour on the water with the Perma-Trim, I have a bunch of data about speed and RPM both before and after the Perma-Trim, and honestly, there is not a big difference in terms of optimum performance. The big difference I see so far is that prior to the Perma-Trim, the boat required full tabs to get up on plane easily, whereas tabs are no longer needed at all to get up quickly onto plane. All testing so far has been done with 3/4 tank of gas and one person (light load). Heavier loads will probably demonstrate a greater benefit of the Perma-Trim in terms of getting on plane.
The boat is now more sensitive to engine trim, and this seems to make the difference. She comes up on plane smoothly and quickly now, but still doesn't truly plane out (stern completely up and bracket not dragging & throwing spray) until about 20-22 mph unless I give her a lot of tabs, which makes her very inefficient obviously. The boat is also now more sensitive to side-to-side trim, so I have to be more careful with the tabs, depending on sea state and course.
Bottom line, the Perma-Trim did not have a dramatic impact (good or bad), but did make it so that I don't have to fiddle with the trim tabs while coming up on plane, and I consider that a benefit worth the price. I can now leave the tabs retracted (all the way "up" or "bow up") and use the engine trim (down) to push the bow down into the sea while coming up on plane. Then depending on sea state, I can trim the motor up a bit for more efficiency. The other effect of the Perma-Trim is that the transition from plowing to planing is very gradual and smooth now - you can't feel a sudden transition like you use to feel with my old motor and prior to the Perma-Trim.
I think I can still get better performance by playing around with the prop and engine height, but I'm going to spend more time with the current setup before I make a decision. I think a 15" Mirage or Enertia prop would be beter and also give better cruising speed than the current Solas 13 prop. Cruising speed now is probably around 22-25 mph (for best economy) which is about 4200-4500 rpm depending on sea state.
I did notice that WOT used to peg out at 6,000 rpm (rev limiter) before the Perma-Trim, but now seems to stop at around 5800 or 5900, so there is apparently some loss of top end, but it may have been that I had the engine trimmed down too far.
