Grog

Hotlavey -

85 mph on a 29' deep V sounds pretty impressive.

My first cut at a new prop was a Hydromotive P5, 26P which got me to 71 gps at 5250 rpm. (11 mph increase from pre-Whipple). I traded it in for a 27P and lost about 2 mph at 5000 rpm. The slip numbers went up from 10% to 12%. I am sold on the 5-blade prop. The acceleration and hole shot are great. I may be sacrificing 1-2 mph top end but overall performance makes up for it.
Throttle-up tells me that the new P5X will be out around the third week of May. It is supposed to run like a labbed Bravo. I am anxious to try it out.

Matt and Julie.....CAN YOU HEAR ME?!?!? VERY VERY VERY ANXIOUS!!!!!!!!!


1999 271 Formula Fastech
502MPI
1700' elev
90 deg temps
2 people
1/3 fuel

hotlavey

I've heard about the 5 blade but holy smoke are those puppies expensive! I am really not interested in hole shots as my Bravo XZ would jump overboard if I nailed the throttle now. Mid-range and up is what I like and the Bravo 4 blade works fine, even tho the 5 may be a little better mid-range. Not really sure the amount of improved performance would justify the cost. Besides, if my wife found out what I have been spending on the boat lately I'd be talking a few octives higher and sleeping with the Whipple.

Nordicflame

Hot Lavey,
Sounds like your getting her dialed in nicely. You are hooking up really well with that boat. We just got back from the Heatwave and I was spinning a stock 30 on our 28 Heat to 5600 and got got a GPS 85.2 on short blast. This hull is pretty notorious for high slip numbers though; not nearly as efficient as your Lavey. I will say though, it feels like it’s on tracks. Rock solid at those speeds.

I have a P5-X coming from Throttle Up that I’m hoping will remedy some of this slippage. I’m shouting also Grog
I think my particular boat is a prime candidate for this prop. I’ll let you know how it works out if I get it in time for a Memorial Day trip to Mead. It probably won’t be enough prop (27 pitch) because I actually bought it for our higher elevations here locally. It should still be a good indicator of how it performs overall though. If it works as well as I hope, I’ll probably sell my 28 and 30 Bravo and buy a 29 P5-X for our lower elevation trips.

Did they check your tach when setting it up? It seems most tachs read about 150-200 high. If that is the case you may be only turning 4850 or so and leaving a lot of torque load on the prop slowing it down a bit. A stock 28 may get you up around 5300 and really loosen the hull up quite a bit and she should run really good.
Sounds like your having a blast!! Good luck with all and be careful. It may not be nearly as fast as some of these rockets but it still feels fast to me
Dave

hotlavey

Dave, you must be running some major power to spin a stock 30 prop 5600. I'll be really interested in your results at Mead in a few weeks. Hope you get some major increases.
I'll be at Mead myself for the Lavey Regatta in Sept. I hear water levels there are not so good.
What is causing your high slip numbers and how do you determine that? They don't seem to be affecting your top end- 85 on a short blast is not too shabby. It took me some time to get to 84.
You brought up a good point re: the accuracy of the tach. I don't think it's ever been calibrated. I'll have to research that and see where that can be done.
I may be interested in your 28 if you decide to sell it. Keep me posted on that as well as your test on the 5 blade.
You're correct about the other "rockets". There is some major speed going on nowadays. 80's are not slow but comparred to some it's crawling. However, I still get bugs on my glasses so I know I'm moving.
Where do you do your boating? You mentioned high altitude and Mead, just wondering.
I hope you're having as much fun as I am trying to work out all these little puzzles. Gives me an excuse to get back on the water a lot, but damn, I'm blowing through a ton of fuel.
Good hearing from you again, and good luck with the P5.
Be careful and keep in touch.

Tom

Nordicflame

Heck Tom,
It’s easy to spin them that high when they slip that bad D: D: D:
Really though, I run a custom built ProCharged 548. I think the slip is from the very high X dimension in combination with the stepped hull.
Yes the water level is low at Mead but as long as the ramps are in good shape, there’s still a ton of lake.
We are from the Northern Utah region where our local lakes range from 4500-6500 feet. We frequent Powell and Mead for long weekends and such and then do most of our boating locally. Havasu once or twice a year.
I don’t know about calibrating your tach but you can have your mechanic check it with his scan tool I believe.
I’ll keep you posted on the P5-X results.
Your right, it is fun but not too economical…however, since the supercharger I haven’t noticed any big increase in fuel usage unless I’m running real hard (obviously). Actually it seems when cruising for long rides that it actually is more efficient with the bigger props ;o)
Keep us posted on you results as well,
Dave

hotlavey

Dave, a quick question. Why did you choose a P5X over a Quad 4? I noticed on the posted race results that most of the top boats were running Quad4's. Just wondering.
Tom

Nordicflame

The Q4 is probably a tad bit faster if you don't have a slip problem. A good friend of mine tried a P5-X on his 28 Nordic with outstanding results.
He also tried a Q4-X with very poor results. It's all about the boat you put it on I suppose. There's only one way to tell...TESTING

hotlavey

Now that I have the Whipple dialed in I am thinking about selling my complete 2002 EFI System. It has the mono-blade setup from ASM and the Teague Flame Arrestor. It has 68 hours on it. Not sure what the value is- anyone???

28Eliminator

NordicHeat, You said that the P5-X produced great results on your friends Heat. How muck did he gain.
We just installed a Procharger on my friends 28 Heat non-step and it is running good, but the slip is about 17%-18% with a 26 & 28 Bravo1 lab. We are hitting 71, but I think we are running a little slower than we should. I'm also running about 20% slip, but I'm running 80mph and was thinking about trying a 5 blade of some sort to see how it does.

Nordicflame

Rockie,
The numbers on your friends Heat sound about right. Pre-supercharger (N.A. 540c.i. ~575 hp) I could turn a 26 to ~5500 and run 72-73 and the 28 would run the same at 5100-5200.

The testing on my buddies Heat were close on speed runs but the handling, planning and most of all, the cruise performance were the deciding factors for me.
His testing was based on back to back runs with my personal 28 Bravo that was just balanced and trued by Bronson/Hill (not labbed) and a 27 P5-X.
The hole shot is said to feel like a Bravo 3 with no slip at all with the 5 blade. Also with the P5-X the boat could plane down to 20 mph where as the 28 cannot hold a plane under 27 mph. The cruise numbers were the big factor for me. With the 28 I can barely maintain 41 mph at 3500 rpm. The 27 P5-X would run low 50’s at the same 3500 rpm. This is where I spend most of my time when cruising up and down Powell or any other long runs.
The WOT runs he made were very close (for reference, his power is approximately 600 hp naturally aspirated and his hull is stepped) He could spin the 28 Bravo to 5150 and 72.6. The 27 P5-X spun to 5050 and 72.4. This was on about one foot of chop. The interesting part was he tested once again back to back on glass water and the 28 Bravo would only spin to 4900 and barely 69 mph, the P5-X ran the exact same numbers it did on the chop, 5050 and 72.4. This just tells me it carries the boat much, much better.

I ordered a 27 for me. This is a replacement for the 28 used above. It will be my high altitude prop as was my 28. At 5000 feet I turned my 28 5600 rpm and 81 mph consistently on GPS. So I’m very anxious to give the 27 P5-X a whirl to 5600 rpm at my home elevations. If it works out as well as I think it will, I will sell my 28 and 30 and then buy me a 29 P5-X for my Mead and Havasu trips )

Sorry for the long winded response…
I’ll keep you posted when I get it.
Dave