I just completed a TRS to Bravo conversion. I have an 1988 Formula 357 with 525sc(clones). I took it out today for a shake down cruise and I could not get it on plane. The prop shafts are 5.75" off the bottom of the boat I figured that that was plenty of room for a good bite, but they break loose at about 1800rpms and spin. I have hydromotive quad IV's on it right now with 24" pich. I also have a set of mirage plus 25's, mirage 23's and a set of revolution 4's with 23" pitch. I figure they are all to little in pitch but I need a benchmark to get the right set. I am thinking I need spacers but I did a lot of research on this before I did it and I don't think I went to high with the drives...did I? My question is wich set of props will I have the best chance to get this thing on plane...or should I put spacers in?

Thanks Joe

5.75 off the bottom ? check and see how mch lower then the lowest part of hull. the bottom of the V. I think your drives are too high. i did the trs to konrad conversion , and had the same problem, i put in spacers and fixed the problem. i couldnt get on plane , would break loose at the 1800 rpm, now with the spacers she jumps rite up and goes

I would start with the 23" mirage+ and move up to the 25 if it worked out well.. My experience is with a much smaller boat, but the Hydromotive is much more likely to blow out getting on plane than any of my other props. If you are propped well (pitch wise) with the 24 Hydro then the 25 mirage+ may work well anyway. Boat attitude may be a whole different story.

Just my $.02

Rene

I am going to try the mirage 25" first but I figure that a 4 blade would grab better than a 3 blade so I am not going to expect anything will come of it. How does one know what size spacer to use if that is what is nessesary? Who has the spacers?

trick marine has the brovo spacers. with my konrads i tried 1" spacers and that wasnt enough. i sent them back and ended up with 1 3/4" spacers. GOOD LUCK

Maybe do to the fact that you took about 350 to 400 lbs at least of weight out of that back of the boat and it sits higher in the water your new X deminsion might be way off. I ran into the same problem years ago when I replaced my old merc two( big as a trs) and replaced it with a alpha one in a 1969 seayray pachanga. I put it in to high didn't take into the fact that the alpha was much lighter and the boat sat higher in the water. Just my 2 cents. JOHN

hey joe just did the same conversion on my 34 scarab III and set my propshaft at 4 1/2 below with no problems at all with getting on plane even 10 people and half tank of gas i run bravo 1s get a set of those and give it a try i bet you will get on plane no problem almost identical hull about same weight

Good to hear that one...I'm gonna try my Mirage Plus 25's to see if it will plane first before I start spending $ on different props...It really pizzes me off that I went a little conservative compared to everyone else and still have problems with planing. Sure glad I didn't go inside of 5" like I had planned!

Joe

The Revolution 4 propellers turning inward would be my first suggestion. If you're truely 5.5" below, it should work.

i,m surprised you are having that much trouble with yours mine comes up on plane so well, better than it ever did with the trs had all kinds of 3 blades back in the day,they would blow out on take off in rough water all the time,from my experience and a ton of researce ,try bravo 1s you can find them everywhere plus the best thing i found was my cruise speed is great