The New Gen-2 Torquemaster (aka: Wingmaster) was designed to utilize existing Verado-Gearcase gearset and internals (which have a WELL PROVEN track-record), with a new housing/propshaft that includes several performance improvements:
-Cambered skeg (w/Torque Tab) that reduces steering torque at higher speeds, and improves handling/stability
-A widened/vented strut area (above the bullet of the case) to reduce drag, and improve handling at speed
-Spray shield (looks like a mininature "wing") at forward end of gearcase, that directs water toward side water inlets (and helps reduce drag by limiting area of gearcase exposed to water)
-Only 3 side-water inlet openings on each side of the gearcase (plus low water pickup inlets), allowing for higher-mounting height running, while still maintaining adequate water pressure (recommend 18 psi as the minimum target pressure).
APPLICATIONS: This gearcase is best suited to LIGHTER boat hulls, that will CONSISTENTLY (as in most any day of the year) achieve speeds in excess of 80 MPH. For heavier hulls, or hulls that will not CONSISTENTLY reach this speed, the Servicemaster/Verado gearcase is likely a much better choice.
Keep in mind- at present there are TWO SEPARATE model numbers for 225 or 250 ProXS 20" engines. When ordering an engine, your selling dealer should be capable of assisting you in determining the CORRECT model for your particular application. Due to the complexity of making the proper choice- it is strongly recommended that you deal with a LOCAL Authorized Mercury dealer when purchasing engines.
GENERAL SETUP GUIDELINES:
-Additional setback required for best performance. These gearcases will usually perform best with a MINIMUM setback of 24" from the pad or keel (to the engine mounting surface). Reports we're receiving are that the further back you go (*within the maximum capacity/rating of the transom of course*), the better they perform. Many are seeing excellent results at 24+ inches (and are achieving previously unheard-of slip numbers).
-Engine mounting height will need to be INCREASED, as compared to previous Gen-1 Torquemaster Equipped models. In most cases, 3/4" (one mounting hole) to 1" height increase works best (but may vary, based on the setback achieved). Monitor water pressure, WOT RPM's, and GPS Speed as indicators of how effective the setback and engine height is. If replacing a Standard (Servicemaster) Gearcase model engine with a new Gen-2 Torquemaster model engine, start ONE MOUNTING HOLE HIGHER (3/4" higher).
For applications where a NON-TORQUEMASTER gearcase was previously used (or no documented previous setup information is available)... the following calculations may prove helpful (achieve optimum setback FIRST for best results):
1. Level the engine “cavitation plate” with the keel of the boat (running surface, or “pad” on a bass boat) by using the power trim button. This measurement is best achieved using a digital level.
2. Measure from the back of the boat’s running surface (pad) to the gearcase nose cone in inches
3. Multiply that figure by 0.181
4. Using a laser or a straight edge, extend the plane the keel is on out to the gearcase.
5. The measurement from the top of the straight edge, or where the lazer contacts the gearcase, up to the bottom of the cavitation plate needs to be the distance you calculated using the 0.181 multiplier.
-Prop Selection: Propellers with LARGER BLADE AREAS work best. The choices MOST preferred would be the Bravo-1 FS, Bravo 1-XS, Fury, Trophy Plus, Tempest Plus, Mercury ProMax, Trophy Plus. Larger blade area propellers better utilize the improved gearcase geometry, resulting in excellent slip numbers (in some cases, bordering on "unbelievable" by previous standards). Keep in mind- achieving lower PROP SLIP may require the use of a SMALLER PITCH (often one pitch point LOWER than was used with previous Torquemaster model).
-PVS Opening Sizes: PVS ventilation openings must be reduced by approximately 50% of the size used on previous gearcase models (to lessen chances of blowout on holeshot). Essentially, reduce plugs ONE SIZE from previous used sizes, as a good starting point (see BRAVO-1 XS notes below*).
-Propping RPM Target: Target for 5800-5850 RPM's, loaded with a FULL TOURNAMENT LOAD, Two Persons, and FULL FUEL TANK(s). This will ensure that the engine reaches it's peak Torque and Horsepower range when FULLY LOADED... and leave adequate room within the acceptable RPM band for LIGHTER loading at other times.
*Bravo-1 XS propeller PVS opening reduction can be challenging. One useful option is to install TWO (2) 1" Freeze Plugs in the prop, which can then be DRILLED to achieve adequate ventilation. In many cases, two 1" freeze plugs installed, and drilled to 3/8" openings work well.
Another option is the Bravo-1 FS (which now has standard PVS openings, allowing you to fine-tune for best holeshot).
The above are GENERAL guidelines... and though they are certainly useful, your EXACT results may vary. When working with setback/engine height, use reasonable care and caution to ensure the SAFETY of you, your passengers (and those around you or within the boat's proximity).
IF your engine will not perform when setup via these guidelines, there's likely something WRONG with the engine. Have your local (Authroized) Mercury Dealer refer to the latest service literature and bulletins for guidance.
*This post is now pinned to the "Commonly Asked- Commonly Used" Sticky post, at the top of the Forum, for future reference (near the top of the list, directly below "Engine Break-In").