CB-BLR

Bobl,

My boat usually runs 15%-16% slip using Bravo's & 12%-13% using P5x's.

I believe they are using Bravo props.

The faster the boat is going with the outdrive depth being the same ... the less boat and outdrive/prop there is in the water... therefore increased slip.

The 130mph+ Howard Bullett ran slip numbers in the 18%-20% range at top speed.

I'm beginning to value slip numbers less and less, and look at overall speed and boat handling more and more.
Who the heck cares what the slip percentage is if it is indeed the fastest prop for your boat, and speed is what you are after.

Chris

90mphRAGE

That was my thought. As mph goes up, boat gets higher, lighter, more prop out of the water & increased slip. Spring I'll try 3500 rpm vs 5500 rpm & compare slip % to test the theory.

xcpilot

Wow! Got a few people shook up. Was not my intent. Time I think to look at a few quotes. Perhaps a bit of sober thought.

xcpilot

[QUOTE=CB-BLR;2988040]Somewhere the math is off...
at 29 pitch.. which is what a 30 is stock.. slip is at 6.7%
at 30 pitch .. slip is at a little over 9%

It is hard to believe that a Bravo prop has slip that low ... Hmmm

Anyway... I agree with Steve... demo a Hydromotive 30 P5x. Hydromotive has a demo program. Going up 1 inch in the hydromotives pitch will reduce rpm aproximately 150-170 rpm.

That is my favorite all-around prop.

I regularly spin a labbed 30 p5x at 5600 rpm to 92.8 mph which equals about 12.2% slip

Here's one that's interesting.

xcpilot

[QUOTE=CB-BLR;2992996]Bobl,

My boat usually runs 15%-16% slip using Bravo's & 12%-13% using P5x's.

I believe they are using Bravo props.

The faster the boat is going with the outdrive depth being the same ... the less boat and outdrive/prop there is in the water... therefore increased slip.

Here's another.

xcpilot

Here's another.

xcpilot

Little bit of math. 5500 rpm on a 30 pitch equals 90.6 mph with Bob's 13% slip. This does NOT include anything for cupping-or anything else! Of course my slip would be higher than a 28' much heavier Heat with a shorter drive (12%). Still trying to figure out why I am a liar and no one questions how some get to 93mph with 28 footers that are 10mph slower than 25's.

xcpilot

Last day on the lake I went back to the prop shop and got the 31 P5X five blade Hydromotive to re test. It worked very well and I bought it that day. I was able to spin it 5300 rpms on glass water and the acceleration was pretty good. Thinking my slip number should be down 3% at least with the 5 blade (to like 9%) compared to the Bravo4 according to CB so my speed should be pretty good. I'll let him come up with some math to keep my speed down to maybe 89. Gotta be a way for a 25 with a deeper drive to have a bigger slip than a 28 with a shorter drive.

bobl

Any one that knows me, knows I'm a stickler(sp) for data and accuracy. I make my living doing this. One thing I've learned from talking with all these folks around the country. Weather and water conditions make huge differences. So, trying to compare Chris's, Steve's and my numbers doesn't always work. I've run on Lake Cumberland (where Steve boats a lot) and seen speeds 3-4 MPH faster than I ever saw at my home lake.

I've set up and run quite a few Rage's and Heats. I know those boats very well. You are correct that you cannot compare the 2 boats. The Rage is about 8 mph faster than the Heat and runs much less prop slip with all else being equal. Just my 2 cents worth.

I've tried my best to show that your numbers are indeed mathematically possible. However would you please clarify if that speed is on GPS or not. With the HP you're running, 93 is an exceptional speed based on my experience. Also, where are you boating and what kind of weather conditions?

I've never run a P5X on a Rage. I'm guessing a 31 at 5300 would still be around 93 +/-. My Heat spun a 29 P5X at 6200 and 95 mph. What did you think about the P5X on the Rage?

Bob

Nordicflame

iTrader: (4)

Here's an intersting quote...
Lets see a pic