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On the RPM/AA impeller thing, I think one fact that should be looked at is the range of the torque of the two motors being discussed. I think you'll find that the turbo motor has a higher torque range. (please don't let this start the tq/hp thing). You make that statement and say "(please don't let this start the tq/hp thing)" "Range" has nothing to do with it, and 1200 hp @ 7000 rpm is going to have the same tq. regardless of the type of engine weather it's blown, turbo'd, NA, N20...it's just a formula. (btw...1500hp@7200rpm=1093#') If Unchained's motor is making that much more torque at 7000, then it's also making that much more HP than those other engines mentioned, which could very well be, but the torque "range" has nothing to do with it. It's called boost.
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I undserstand what you are saying. Do you understand THAT BOOST MAKES TORQUE?
I have looked everywhere for the pictures of the two different types of changable on the fly nozzles that I made but can not find them. I think possibly those pictures went out the window with the tornado.
We played with them and thought they helped some, but for unknown reasons, never had them on the clocks. If I remember correctly, I think we were afraid of a malfunction at high speed that might affect steering.
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Our hull stripped (except for intake & steering) weighs 485 +/- 10 #'s (+/- 10 #'s due to accuracy of scales) ... Ready to run w/Mike, close to 1,650 #'s (a few +/- ... + or -, depends on what Mike had for breakfast).
That's pretty light Jak.
My boat weighs 1,920# without me.
Mike looked like about 200# so your boat might weigh 1,450#
I'm dragging along almost 500# more than you with my lake setup.
I seen a dyno video from the guy with a similar EFI turbo engine to mine here in Mi. Same size turbos but less boost. He had over 1000# of torque at 3500 rpm. He was turning a prop and needed low end torque. He broke so many outdrives I lost count. When it held together it pushed a 24' Daytona to well over 130 mph.
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I undserstand what you are saying. Do you understand THAT BOOST MAKES TORQUE?
I have looked everywhere for the pictures of the two different types of changable on the fly nozzles that I made but can not find them. I think possibly those pictures went out the window with the tornado.
We played with them and thought they helped some, but for unknown reasons, never had them on the clocks. If I remember correctly, I think we were afraid of a malfunction at high speed that might affect steering.Did your nozzles stay round when they changed size?
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One did, and the other one got veins in it like the end of an exhaust pipe as it opened. Seemed like the last one worked best. My guess is that round is better. Reasoning is you don't see firemen with square nozzles and we are really trying to do the same thing. (produce thrust). I'll keep looking. I've got a million pictures.
Going back on the roaD NOW AND WILL NOT BE ABLE TO RUN MY COMPUTER FOR A WHILE.
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Round nozzle openings are the optimal shape and the restriction area of the nozzle should be cylindericial ... note the length of the restriction is also very important in order to have good laminar, linear outflow (note, the more the laminar outflow, the more the thrust force is a linear, unidirectional force) out ot the nozzle. The 1/2 to 5/8ths of an inch of the Place Nozzle Inserts restriction are not of optimal length and do not establish a good laminar linear outflow.
If someone wants to get a better understanding of what I've said, I suggest researching Bernoulli's Equation as it applies to Incompressable Fluid Flow through a nozzle or a venturi ... The NASA Library has quite a bit on the subject of nozzles, etc. and, it's online.
This is vary good information here! Have you used the nozzle simulator online?
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Have you used the nozzle simulator online?
What simulator?
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Opps another slip up :D It was linked off the NASA site. Pretty cool tool to understand what UBFJ #454 had typed.
Ken F here it is
http://www.grc.nasa.gov/WWW/K-12/airplane/ienzl.html
Rockets http://exploration.grc.nasa.gov/educ...ket/ienzl.html
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I believe the dyno sheets read about 1402 HP..
was this with/without nos? how much of a shot?
Yes, I suppose that it's a 620 lb boat with pretty much full interior and gas tanks might be a factor there. I have not seen inside the pump lately either.
I've seen him run several times and it is quite impressive. I would love to get a chance to put my data acquisation equipment on the boat. It would help answer some of the questions about it here.
BP, don't take offense here, I'm claimiing no numbers; Just that it is a very fast boat.
duane, i'm certainly not offended, and i'm sure it's fast. but i've seen other boats run 128-130 followed by a pretty large steam cloud, and et reflects it. what i doubt is the AA/7k claim, for 1200-1300 hp. it is either making a LOT more hp than 12-13, it has loading issues, there's something else going on with the pump, or it's not really 7k. i'd tend to believe the 7k, so it's one of the other choices.
jak, there are other ways to get the flow straight without a longer insert.
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That was with the nitrous.
I think Unchained is making a lot more HP than that.