Lund Pro-v 1900 w/Optimax 150 prop opinion

[erixgarage]

Like the title says, 1900 Lund/150 Opti, running mercury black max 19 alum. now & getting 5050 - 5100rpm @ 44 Mph with light/normal load. Just ordered a Tempest Plus 17..... any thoughts or opinions? I'm thinking 5500 - 5600rpm & a whole lot less ventilating in the corners & better rough water performance with 44-45Mph top speed....

[staylor]

..but you may find to get the best performance out of the Tempest Plus you may need to raise the motor 2 holes or so- the Tempest will bite the water a lot better than the aluminum. The Tempest will probably come with 3 of the "L". or large diameter PVS plugs. This should also be in the ballpark for a good holeshot with a rig in your weight class. I would think that with the agressive cup in the Tempest that you'll end up around 5400-5500 rpm with just the prop swap, and raising up the motor 2 holes should pick up another 100 rpm or so. My 2002 150 Opti runs fastest when propped to around 5500-5600 with a normal fishing load. This keeps me under the 5750 limit when running light.
Doug

[erixgarage]

Yeah, I was thinking I could raise the motor at least one hole cause it's all the way down now. Tried it one hole up with the aluminum prop & couldn't trim up much or turn at higher speeds...

[staylor]

..than the aluminum, due to its high rake blades and a little extra diameter. This will carry the bow without needing as much trim- and this alone usually gains some speed since the motor is running more parallel to the water surface. On my 17 ft Starcraft, motor up 3 holes, I run a 21 Tempest or 21 and 23 Trophy Plus 4 blades. If I'm working rough water then I always run the Tempest- it's 14.62 diameter bites a lot better in the rough than the 13.75 diameter Trophy Plus. For absolute top end in smooth water, the Trophy Plus 23 is the quickest, with the other two props very close- within 1-2 mph. I tried running an alum prop once with the motor up 3, but I couldn't get the prop to hook up on hole shot- it just vented and wouldn't plane unless I opened the throttle up to 4500 rpm and waited for the prop to bite.
Doug

[erixgarage]

Tried out the Tempest Plus with the family today, great holeshot, awesome cornering, same 43-44mph & can trim up completely with out blowing out but only 5200rpm. Raising the motor two holes this week & will try it again, hope I gain at least 200 more rpm

[erixgarage]

What do you think, am I on the right track?

[propmann]

Originally Posted by erixgarage

What do you think, am I on the right track?

Yes, raise the motor and see what it does it should give you some more rpms.

[erixgarage]

So I raised the motor up two holes, cav plate is totally out of the water at speed & the Rpms came up about 100 - 150 to 5300 - 5350. Corners really well with no slip, holeshot is great with the three large opening plugs that it came with & speed is up slightly to 44 - 45mph......Still would like those rpms higher though, may have to have some custom work done on the prop?

[staylor]

...or with a light load running at 3/4 throttle in a light 4-6 inch chop coming in at a 45 degree angle....then go up another hole. Raising the motor gives you rpm and speed for free by cutting drag. So I suggest to keep going up until you have venting show up. The reason I check with a light load at mid-speed in a cross chop is because the better props like the Tempest and Trophy Plus stick like glue in turns, but sometimes will vent in a cross chop at a fast cruise speed. The venting will be slight- just a 150 rpm rise or so, and the steering wheel torque will change such that you will need a slight course correction.

If you get to the point where you do start venting on turns or in a cross chop with light load then you just drop the motor down a hole and see what the rpm is. At that point you can figure out what to do with the prop. On props like the Tempest Plus it is easy to drop rpm by raising the pitch- often by adding some cup- but reducing cup to increase rpm doesn't work too well. The Tempest Plus has an area on the back of the blade out by the outer edge that is there to allow a prop shop to add cup. But dropping pitch to raise rpm is not as easy. If you raise the rpm by reducing the cup, then you run the risk of having the prop lose it's bite at the raised motor setting. If a prop shop works the blades themselves to reduce pitch, then you should be able to reduce pitch by 1-2 inches, but you will probably not gain any more speed.

You still need to find the best transom height- or as the bass boat people used to joke when the first Merc and OMC chopper SS props came out in the 1970s- "Find out How High is Up?
Doug

[erixgarage]

Don't think I'm raising the outboard any higher..... just don't feel good about that. Might get the prop pitch worked down an inch though, just to get another 200 - 300 Rpm. Want to keep all the cupping it has now, cause the way it carries the bow & holds in rough water is awesome