Re: 5.0 MPI Albha or Bravo III
Re: 5.0 MPI Albha or Bravo III
Going to the B3 is one thing, but why skimp on a 5.0 and not go 5.7. I couldn't imagine putting a 5.0 in a 25' boat.
Bingo....For the luv of god you could lose 2 drive's and repelace them with SEI for less money. Dont know who suggested doing a bravo on a 260 hp boat but find another salesman...350 ...here
http://www.stingrayboats.com/products/reviews/tb5-95.html
SINGLE-PROP VS. TWIN-PROP
For the first test, the boat was powered with the MerCruiser 350 Magnum using the Alpha One single-prop drive. Theoretically, we expected this single-prop configuration to be the fastest and most efficient, because it has less lower unit and prop in the water to produce drag. And, sure enough, the performance charts show this to be the case. From the charts, we can see that this package was fastest, with a top speed of 50.6 mph, although the difference was slight, with only 0.4 seconds separating first from last. The charts also show it to be most fuel efficient, giving us 4.2 mpg at 3500 rpm and 36.0 mph. In our measured data, the only place the Alpha One drive finished less than tops was in acceleration from 0 to 30 mph where, as expected, it finished last. However, we were surprised that the Alpha's 7.4-second acceleration time was only 0.l-second longer than the second-place Volvo Penta Duoprop. The Alpha also had a slower planing time than both twin-prop units.
With the Alpha drive, the Stingray had a light and free-running feeling, crisp predictable cornering, and as is common with many vee-bottom hulls, a moderate tendency to wander from side to side at displacement speeds. Docking and handling maneuvers were easily controllable, and about as expected for a boat of this size. Overall, the 350 Magnum with an Alpha One drive is a very satisfactory package for the Stingray 719 zp.
Both the Duoprop and the Bravo Three twin-prop units exhibited the same handling characteristics. One attribute of twin-prop drives is that they provide a lot of stern lift, which helps the boat come on plane with much less tendency for the bow to rise. This also allows the hull to maintain a planing attitude at a lower speed. Once on plane, the trim system is less effective at bringing the bow up. Consequently, the boat has a much more glued-to-the-water feeling. Nonetheless, as our figures show, this has little effect on top speed. Other characteristics are that, with counter-rotating props, there is no tendency for the hull to list from side to side as trim angle is changed and there is a secure feel to the handling that just isn't there with single-prop drives. Cornering is another area where a twin-prop drive excels. While the Stingray 719 zp corners quite well with the single-prop Alpha One drive, when equipped with a twinprop drive, the boat maintains a tenacious grip on the water and it is nearly impossible to get the props to ventilate or make the boat slide sideways or spin out. Furthermore, you can take your hands off the steering wheel in a turn (although we do not recommend this) and it will still maintain its turning radius; the counter rotation of the props eliminates steering-wheel torque. So,even though the Alpha One was a shade faster, for overall performance we'd opt for a twin-prop drive.
Hmmm Stingray does not offer a Volvo drive
