I am curious to know the transom angle of the various boats. My 18 is a converted I/O and the transom angle is 14 degrees. What is yours? jim
That's a darn good question! I thought I remembered hearing that the 18' outboards were 11 degrees, but I can't verify that.
I guess I have no takers,so I will take this to the next level and say that I think 17-18 degrees is ideal for a modern motor. I am at 19 degrees with the wedge and I have plenty of in and out trim for any situation. jim
Jim I'll bite. I'll try to measure it tonight and plug it into the formula. I finally set up my hangar computer with direct ethernet cable, as my wireless out there was just too unreliable (and too slow for uploading 28 day nav database updates on the GPS units for the a/c). Now that I have reliable internet service on that computer, it will be easier to post boat related stuff while I'm right there next to the 'ol tub. I am concerned about RiverRat's comments concerning his test drive as respects trim - specifically the "tuck" but it sounds like he can still make a trim stop adjustment to get a bit more tuck. I did not install a wedge, with the idea that I could try it without first and add one if I need one. I'll be curious to see what the angle is. I hope it is closer to 17 rather than 11. Is there something different about modern engines that would require more transom angle for low speed planing?
Mark, I doubt if there is any difference in the transom angle on any of the boats. There has been a lot of talk but no measurements. I don't know the specific answer to your question about the modern engines except to say that my modified 18 is the only boat I have ever owned that now has enough in trim. I don't always use it and it still has plenty of out trim, so I see no disadvantage other than it is different which is fine with me. When I look at my 50's to 60's Merc manual it says that the motors were designed for 12 degrees. If you look at the specs for modern boats they are mostly at bigger angles. My guru likes 18 degrees for his boats. I like my 19 degrees. This is a personal thing. I post this stuff in hopes someone will be helped. I have heard twinrig drivers complain about not enough in trim, but I have yet to see a wedge on one. I got into this originally because I was trying to minimize the turn around wake in the swivel tournaments. The upstream wakes tend to drift down into the show course before the session is over and can trip up the skier because the waves are unexpected. In a tournament they are doing very difficult moves that you never see in shows because they need calm water which does not exist in a show. I have seen swivelers fall in tournaments because of this and they never knew what happened. Then I realized that it made the boat easier to drive in the slow stuff. It makes the wake a little easier on my neighbors water front erosion which I am sure they appreciate. The wedge is certainly not a requirement for recreational or club skiing. jim
Pete had a wedge on his boat when I first rigged a motor for him in 1997. It works well on the 17.6's I don't really feel that 20 ft singles need it. A twin without counter rotation with wedges is almost undriveable when fully tucked under. Even with Hydraulic steering it is hard to drive so the wedges are counter productive. We tried it back in 2002 and took them off right away. Speed holding with a twin has never been a problem with our boats. Never tried wedges on a counter rotation twin because we've never had counter rotation on a twin.
It does increase the torque steer a little. I have always wondered if the bow ballast could be reduced on a twin rig with a wedge. I guess it would have to be a counter rotator. jim
Jim I measured mine tonight. It is between 13 and 14 degrees. If I use a smaller square, "X" is 1.5 and "Y" is 6, which comes out to 14 degrees. When I use a larger square, "X" is 3.8 and "Y" is 16, which comes out to 13 degrees. MarkBano
That is close enough for me. I think they are all the same. If you measured it on the other side, it would probably be a little different. I doubt if the transom is perfectly flat or uniform. jim
