As suggested by Mark, my prop needs...

[ohmagoo]

Well, I don't know what I need yet. That's probably the biggest issue.

I do know the boat is sluggish getting out of the water. Often, a weight transfer has to happen for the bow to set back down and get her up on plane...i.e., anyone in the back has to move forward to get the nose down.

As mentioned, squeezing every last MPH of speed out of this boat is not top priority. I've been told she should be a 60 MPH boat, and been told I should see 65. I have seen 59 on GPS @ about 5050 RPM...just not sure if this is the best it will do. At 59...the boat seemed reasonably stable and controllable. Getting there, though, between a bit of chine walk, and the bounce...well certainly kept the attention level up there.

I've been told this Mirage Plus 23 is a bow lifting prop and I should have more of a stern lifter. Also been told that the X dimension on this boat is very high which will have some sort of impact on speed and handling. Again, I don't know yet, since I do not know what different props will do for the boat. Yet.

Ice is gone on the upper lake today, but still some on the lower one....soon very soon.

 

[flyby knight]

Well, I don't know what I need yet. That's probably the biggest issue.

I do know the boat is sluggish getting out of the water. Often, a weight transfer has to happen for the bow to set back down and get her up on plane...i.e., anyone in the back has to move forward to get the nose down.

As mentioned, squeezing every last MPH of speed out of this boat is not top priority. I've been told she should be a 60 MPH boat, and been told I should see 65. I have seen 59 on GPS @ about 5050 RPM...just not sure if this is the best it will do. At 59...the boat seemed reasonably stable and controllable. Getting there, though, between a bit of chine walk, and the bounce...well certainly kept the attention level up there.

I've been told this Mirage Plus 23 is a bow lifting prop and I should have more of a stern lifter. Also been told that the X dimension on this boat is very high which will have some sort of impact on speed and handling. Again, I don't know yet, since I do not know what different props will do for the boat. Yet.

Ice is gone on the upper lake today, but still some on the lower one....soon very soon.

If you are looking for a prop that improves handling of that boat in every way I would recommend you try a 22 bravo. I ran the 23 mirage plus on my Persuader & switched to the bravo and never went back. A bravo may scrub a couple mph from top end but well worth it imo.

 

[Mark]

Ok Mr Magoo, I have some info that may be helpful. Although my I/O is not a ZT230 it is very similar and has the same drive. It is a Caravelle Interceptor 232. 23' long, 3300 lbs and has a pad bottom like a ZT. My motor is a 320 HP 6.2L MPI with a 1.65 Bravo 1 drive. Your rig should be good for 60 MPH, I would doubt you will see 65... although I am not an expert on the ZT.

First you need to check and see what gear ratio yours is. It will be stamped on the starboard side of the Bravo. Most of the time they mated the 6.2L with the 1.65 so that you could use the same props as the 454 Mercruiser it replaced. Here are my numbers. All speeds are GPS and rounded to the the nearest 1/2 mph as different runs gave different decimals as the condition changed.

Props :------------------------20 Enertia-------------22 Enertia-----------21 Vengeance------------21 Mirage (detuned 23)----23 Mirage---------23 Tempest

Holeshot---------------------- Excellent --------------Very Good------------Excellent-------------------Very Good------------------Good--------------Very Good

3000 RPM ---------------------27 mph-----------------30 mph---------------31 mph--------------------33 mph--------------------34 mph--------------34 mph

4000 RPM----------------------39 mph-----------------43 mph---------------42.5 mph------------------44 mph -------------------45 mph--------------45 mph

RPM @ WOT-------------------5,400--------------------5100------------------5200-----------------------5100 -----------------------4800-----------------4950
-----------------------------Hit Rev Limiter
GPS speed WOT---------------55.5-----------------------57.5------------------58-------------------------60---------------------------60-------------------61

This is what I can tell you. If you have the 1.65 gears your boat is going to like a big diameter prop like the 23 Mirage best. If you have 1.50 gears your rig is going to prefer a smaller diameter prop like the Enertia since the motor has to spin it faster. In which case you will likely need a 21 Enertia. They have superior holeshot and grip but in my case I preferred the superior cruise speeds from the Mirage.

Finally, you can improve your holeshot immensely by putting in larger hole PVS plugs in your prop. That is assuming you are running your exhaust thru the prop. Once you switch to thru hull exhaust the plugs are useless. Some Mirage props do not have PVS holes. If that is the case you will need to find a PVS prop. Even though the PVS system was designed for outboards I find it makes a huge difference on my Interceptor. Here is a pic of my ride. Good luck.

[/URL]

 

[ohmagoo]

If you are looking for a prop that improves handling of that boat in every way I would recommend you try a 22 bravo. I ran the 23 mirage plus on my Persuader & switched to the bravo and never went back. A bravo may scrub a couple mph from top end but well worth it imo.

Thank you...I'll add this to the list for testing.

 

[ohmagoo]

Ok Mr Magoo, I have some info that may be helpful. Although my I/O is not a ZT230 it is very similar and has the same drive. It is a Caravelle Interceptor 232. 23' long, 3300 lbs and has a pad bottom like a ZT. My motor is a 320 HP 6.2L MPI with a 1.65 Bravo 1 drive. Your rig should be good for 60 MPH, I would doubt you will see 65... although I am not an expert on the ZT.

First you need to check and see what gear ratio yours is. It will be stamped on the starboard side of the Bravo. Most of the time they mated the 6.2L with the 1.65 so that you could use the same props as the 454 Mercruiser it replaced. Here are my numbers. All speeds are GPS and rounded to the the nearest 1/2 mph as different runs gave different decimals as the condition changed.

Props :------------------------20 Enertia-------------22 Enertia-----------21 Vengeance------------21 Mirage (detuned 23)----23 Mirage---------23 Tempest

Holeshot---------------------- Excellent --------------Very Good------------Excellent-------------------Very Good------------------Good--------------Very Good

3000 RPM ---------------------27 mph-----------------30 mph---------------31 mph--------------------33 mph--------------------34 mph--------------34 mph

4000 RPM----------------------39 mph-----------------43 mph---------------42.5 mph------------------44 mph -------------------45 mph--------------45 mph

RPM @ WOT-------------------5,400--------------------5100------------------5200-----------------------5100 -----------------------4800-----------------4950
-----------------------------Hit Rev Limiter
GPS speed WOT---------------55.5-----------------------57.5------------------58-------------------------60---------------------------60-------------------61

This is what I can tell you. If you have the 1.65 gears your boat is going to like a big diameter prop like the 23 Mirage best. If you have 1.50 gears your rig is going to prefer a smaller diameter prop like the Enertia since the motor has to spin it faster. In which case you will likely need a 21 Enertia. They have superior holeshot and grip but in my case I preferred the superior cruise speeds from the Mirage.

Finally, you can improve your holeshot immensely by putting in larger hole PVS plugs in your prop. That is assuming you are running your exhaust thru the prop. Once you switch to thru hull exhaust the plugs are useless. Some Mirage props do not have PVS holes. If that is the case you will need to find a PVS prop. Even though the PVS system was designed for outboards I find it makes a huge difference on my Interceptor. Here is a pic of my ride. Good luck.

[/URL]

Thanks!! Nice boat.

A lot of good information there. I've been told about the PVS holes before and will certainly keep that in the equation. Playing with that many props could get expensive. I do believe the ratio is 1.65 but I'll confirm that. From all this info, a good starting point would be a day on the water with a Bravo 22, Mirage 21 and a 23 Tempest.

Again thanks....looking forward to this testing.

 

[Mark]

Right... I was trying to save you the expense of trying all these props. Depending on your gear ratio most will do fine. No magic bullet that stands out. I would eliminate the Tempest for a Checkmate as it will probably cause porpoise since it has the most lift. The Interceptor has an extended running surface (acts like trim tabs) and does not porpoise ever. The 22 Bravo is a good choice if speed is not your only criterion and if you are trying to minimize porpoise.
Generally the Mirage has been the go to prop on similar Bajas for years. My 21 Mirage is actually stamped Baja Performance Boats on the side. BTW I would sell you any of these props. I got carried away prop testing. You might like the 21 Mirage since it actually is more like a 22.

 

[ianz]

That is a great prop comparison