Checkmate Pulsare 2400 with 300R performance

**Pulsare2400** · 05-25-2021, 08:31 AM

Originally Posted by wicheckmate

I would be tempted to try a Bravo 1 on there with a set of vent holes.

I ran a 26P Bravo 1 on mine and it only turned 5800 rpm at 70 mph, vs the 24FS that turned 6250 at 72 mph (also turned the FS at 6450 but it was trimmed a bit high). The Bravo 1 26P actually accelerated my boat on the plane much faster than the 24FS did. Likely due to the longer barrel and full length diffuser and it had no chine walking (but never ran over 70 mph either). Neither prop needed vent holes open with my 300R. Based on Trace3's comments, perhaps my tach might be out as well. I looked at the digital recall of the highest rpm (Livorsi) and it is connected to the Smartcraft system so I assumed it is accurate but maybe not. Based on Trace3 comments, I think I have to be looking for a ProMax to try next.

**wicheckmate** · 05-25-2021, 09:17 AM

pulsare 2400 you have a PM.

**Pulsare2400** · 05-25-2021, 02:30 PM

If you only hit 6350 rpm with the 23PM with the tech on board and it was not pulling any power based on his comments, then that is almost perfect. A 24PM at the same slip would likely run 6100 perhaps 6200? I think you might want a 24 labbed PM which is what Mercury Racing told me to try. If you really were not pulling power, a 24.5 or 25 PM might be too much unless you get them worked later. Just my best guess, I could be wrong.

**TraceF3** · 05-25-2021, 02:56 PM

I agree almost perfect (at this point) but as I get better at managing the chine walk and as the motor gets more broken in I think she'll develop a little more power. We'll see. Also I haven't run at WOT more than a mile or so.

Spoke to Randy, his prop is a Hill Pleasure 5. It's what he runs on his Superboat. Just spitballin'

**Pulsare2400** · 05-25-2021, 03:18 PM

I agree with you, but I doubt you will need more than a 24PM, or a labbed 24PM. I ran a Hill Pleasure 5 on mine. It was 23P. It looked like tug boat prop but it surprised me. It was very smooth, but 23P is the highest they make. I turned it at 6400 rpm, going 68 mph with 17% slip. I think the diameter was just too small. I also guessed the engine was already pulling power but that was a guess. When the tech checked yours, was the laptop hooked up while you ran 72.7 mph with the 23PM prop? You turned the 23PFS very close to what I think I would have turned one based on my 24P FS. I have about 60 hours on mine and it still runs the same mph as it did with 3 hours on it, I was hoping for more. My friend has a BRX with a 300R and his sounds much faster than mine but has uncontrollable chine walk around 71 - 72 mph.

**TraceF3** · 05-25-2021, 03:38 PM

Yes the tech was in the boat on the computer while I was driving.

**mjw930** · 05-25-2021, 05:08 PM

These are the 4 setting I like. There are about 40 to choose from in the tool.

DemandLinear = What the operator is requesting
Demand = What the computer decided to apply
abs_TPS = Absolute Throttle Position

This was a couple runs I made with the 250 on the Key West. Note the Demand is rarely equal to throttle aside from 100% or idle.

Click image for larger version.

Name: B0F0EC6B-9491-4B2D-B1FB-E0183DBCD61B.jpeg
Views: 23
Size: 196.2 KB
ID: 487604

Click image for larger version.

Name: 34E798B6-DC00-4337-88C1-5E1B8CDE7BE1.jpeg
Views: 14
Size: 203.1 KB
ID: 487605

**Pulsare2400** · 05-25-2021, 07:44 PM

Thanks Mark, I am learning. The bottom one is easy since all 3 are at 100% and the rpm was 5647 so I assume the stick was pinned. The one above at 3823 rpm I want to understand. Which of the 3 are the demand linear, demand and butterfly position? Thanks for your help.

**mjw930** · 05-25-2021, 08:37 PM

Demand linear is what you are requesting (the position of the control)
Demand is what the computer is demanding of the motor based on a number of things, including your throttle setting
TPS is just the raw number the butterfly is open in response to the computers Demand.

There’s another one I didn’t display called Demand Linear with Guardian. That’s used when the motor goes into guardian mode such as overheating or in reverse where you can’t get full throttle and at the rev limiter.

Here’s an extract Mercury published to explain how to prop with ASC.

IMPORTANT: Propping of the boat can be done as normally done with all other MerCruiser products, but to achieve the best optimum propeller selection you can use the propping procedure below with the G3 tool to verify your propeller selection.
A special propping procedure using CDS G3 should be used for optimum propping.
• Install the best guess propeller.
• Run the engine at 100% Demand Linear (demand request by operator) with optimum trim. The Demand (demand request by control software) and Demand Linear with Guardian (demand request by Guardian) should both equal 100%.
• If RPM is less than 4800 but the Demand (demand request by control software), Demand Linear (demand request by operator), and Demand Linear with Guardian (demand request by Guardian) are all 100%, install a smaller pitch propeller.
• If RPM is greater than 5200 even momentarily, and Demand (demand request by control software) and Demand Linear with Guardian (demand request by Guardian) cannot both reach 100%, install a larger pitch propeller. (This means software Demand is pulling back on the throttle to stop from overspeed.)
• If RPM is between 4800 and 5200, the propeller is correct, depending on the customer’s preference.

Obviously this is not on a 300R but you get the idea.

**Pulsare2400** · 05-25-2021, 10:06 PM

Thanks for the explanation Mark. I was actually interested in the exact numbers you displayed in the screenshot on your post. 60.69; 75.26; 35.32. Is the lowest number (35.32) the butterfly position? Then if I assume that 60.69 is demand linear, why has the ECM decided to apply 75.26% but the throttle blade is barely open. Was this screen shot during acceleration or steady state cruising at 3823 rpm.

**mjw930** · 05-25-2021, 10:37 PM

It was at cruise so I assume the motor was commanding more to maintain speed. You can’t correlate TPS with demand. Demand controls timing, injectors and throttle and when I was watching the replay, demand moved a lot more than TPS, demand linear, the throttle setting, was static. At these settings the motor is probably not making much more than 120HP so a 4.6L motor doesn’t need a big air opening to make that much power.

I think I have a recording of this run, I’ll see if I can make a video with a lot more data, including speed over water, it’s interesting how much is happening depending on load, speed and throttle setting.

**TraceF3** · 06-14-2021, 06:57 AM

It's getting faster! 73.5 on the GPS this weekend. Trick is to keep it from walking. Still trying to get a 24p Promax.

**TraceF3** · 06-14-2021, 07:05 AM

Originally Posted by kct11

I had a 24 crawl through with a 300xs. By myself high 70's was the norm with a hydromotive 27p. Borrowed a 28.bblades baster and went just over 80. Torqmaster and 21 inches of set back.

Any chance you have a picture of the set back set up?

**kct11** · 06-14-2021, 07:44 AM

Originally Posted by TraceF3

Any chance you have a picture of the set back set up?

Best I can do, long time ago. 5.5 cmc bolted to a 16 static i made out of flat plate and angle.

Click image for larger version.

Name: Screenshot_20210614-083951_Facebook.jpg
Views: 32
Size: 292.7 KB
ID: 488744

**Pulsare2400** · 06-14-2021, 07:59 AM

Hi Trace, when you ran that 73.5, were the water and air conditions better, or did you pick up the speed due to controlling the walking better? Any idea how far it was trimmed out? Even on the gauge? My Livorsi gauge is set up so that it goes to the 4th line, and after that the trailer trim engages. I am usually running between the 3rd and 4th line but you have a different prop and a bit less weight. If I trim mine to run 70 mph, I do not have to correct the walk but it will rock a bit side to side. If I trim more and get it to 72 mph, I am steady correcting the walking to keep it controlled but I am trimmed out higher as well.