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pics collection for the Predator C30
http://i1238.photobucket.com/albums/...nter/c30_2.jpg
Printable View
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pics collection for the Predator C30
http://i1238.photobucket.com/albums/...nter/c30_2.jpg
That looks sweet!! Ya think shes faster with 300xs motors over 400R,s?
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I think that with 300XS, the Predator C30 is good for 105MPH. The owner of this one is still dialing in this boat.
With 400R's, the top-speed would be 112~115MPH (this is a narrow tunnel model)
The wide body hull (C306WB) should be around 119~121MPH
we shall see
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The widebody model C306WB will incorporate over 12 mold modifications from both Arnaldo and DougWright. You cannot just widen the hull, there are catamaran running characteristics that must be enhanced, like hull lift, tunnel compression, and porpoise.
This is the speed with twin 300XS. One down, two more predictions to complete
http://i1238.photobucket.com/albums/...misc/photo.jpg
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The reason I ask Noli, is because there is no data to prove that just a widened tunnel gains any speed. The wide tunnel outboard cats you see that are fast - DW32s, all the X-Cats - are faster because they also have narrower sponsons along with the wider tunnel. If you just take a standard outboard cat - Skater 28/30, Spectre 30/32, etc - and widen the tunnel 8'-12", the boat is not necessarily going to gain speed. It will be more stable in the rough, because of the wider stance, but it won't necessarily gain any speed. I just talked to Pete about this yesterday, and it's what we both agreed on - and he's been widening tunnels on race boats for 20 years now. Look at LOTO, Garth's classic 36 went within just a few mph as fast as Chip's 388 did a few years back, with PSI blower motors from the same engine builder. Not only does the 388 have a wider tunnel, but is also cut down for better aerodynamics, and has a more modern, faster bottom. Don't be surprised if the widened 30 is no faster, or even slower, than the standard tunnel width 30. And I'm saying this presuming that the only difference between the two boats is the widened tunnel - sponsons are identical.
Won't altering the tunnel affect the range that a tunnel hull will porpoise too? It affects the crossover point from hydro to aero lift I believe.
Not at all - at the speeds most outboard cats porpoise, aerodynamic lift isn't doing hardly anything. That tunnel isn't creating lift at 50-70mph. You have to remember that when you widen a boat, you also add weight and more aerodynamic drag. Why do you think aircraft with smaller wingspans are typically faster than aircraft with larger wingspans? The wings that create lift also create drag. There are tradeoffs between lift and drag. The same principles apply to cats - even though the lift being generated by a tunnel is very different from the lift being created by a wing.
Hi Dale,
Both Noli and Predator have been picking Doug's Brain on Bottom improvements. Its my understanding that those improvements will be incorporated into the next boat built. The AMT boat was one of Doug's earliest designs and he's certainly come a long way since then. In crew chiefing for Scott Porta's boat, we've found that the older DW like Scott's has a top speed very close to the newer wider boats. Its not that far apart. However where the wider boats are faster is during the acceleration out of the turns. There's two reasons for this, Scott's boat is an older boat and its a little heavier, However the additional lift of a wider boat gets the boat up out of the water sooner and running over the surface, while the narrower boats need to accelerate to a higher speed to gain the same amount of lift. That is in smooth water. In rough water the advantages seem to go away as the lighter, wider boats seem to be disrupted more with heavy seas. It does stand to reason that a wider wing will create more lift and get the boat moving faster sooner, but that absolute top speed would be a function of the running surface and horsepower available. Gary Ballough has without a doubt the fastest DW in SBI, ( that is until Nick Scafidis is completed, it has some mods that aren't even on Gary's) And his top end is about 5 mph difference. But he also shortened the running surface and is actually at about 30 ft. That allows him to run a lighter weight still, but kills his rough water performance as the bow digs into waves more than the longer boats. Cocoa was exceptionally smooth this year, but you may see that next year if its characteristically rough again. We are going to do some prop testing with Scott's boat and the 300SS's this week, so hopefully we will get some good numbers to post up. ! As an interesting side note, It appears that Canopy design and the Lift that the canopy creates has a measurable impact on Lift. Watch some videos of the HULK boat running. With that over sized canopy that they have, The low pressure area behind the canopy generates a TON of lift !! Watch how it just dances on top of the water, its really noticeable. Nick's boat will be the one to beat next year !! Can't wait to see it fly !!! Fly safe !!
Apologies Rayzor,
I'm not trying to be cocky in not responding in a better way. I am privileged to have and know about the the conversations between Predator and DW, but I cannot disclose in a public forum. Someday when we're having a beer or two, we can discuss as much as you want to :)
P.S. I am not an employee of Predator, I am a customer, which allows me to venture into other "affordable" boat ventures
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Dale, I agree with you 100 percent. If you look at the speeds from LOTO the proof is in the runs. The sponsons on DW are much flatter in the angle of attach than the 308. Personally I think it the main reason as to why they are so much faster is they are much lighter. Darren 32DW weighs under 5000lbs out the door with no fuel. I think based on the weight of my rig and 400's with the right set up i am confident it would run 118 or based on what it runs now and a 130hp increase with a slight weight increase as well.
It is great to see new boats being built just wish he could get them done Faster!!!!!!
Thanks for all of the interesting firsthand observations! I always enjoy reading about others experiences with similar setups. With no true "logged" data from just about any manufacturer, we're always left to come up with our own conclusions. There's so little money in boat racing versus car/motorcycle racing, that manufacturers aren't able to spend the money on R&D to have conclusive answers to the questions we all have. But, then again, that's what makes it so fun! We all have our own ideas, and with specialty builders like Pete and Doug, we get to try out our ideas firsthand.
No offense taken Noli, it's all good! :cheers: I always enjoy the discussion. I'm glad you take my questions as positive, and don't get upset when I question some of your posts. We're all just on here instead of a dock somewhere talking face to face because we all live in different parts of the country.
I agree that weight is a large part of the speed difference between the DW32 and the Skater 318. I think the huge windshield on Steve's 318 is also slowing him down a lot. I've heard Darren's DW weighs 4,800 dry, and I know Steve's 318 weighs 5,500 dry. That difference alone is about 5-6mph. Add another 3-4mph loss for the much larger windshield on Steve's 318, and you've now got the boats running very similar speed. Not knocking Darren's DW at all, that boat is BADASS, and the fastest 30'+ outboard pleasure cat in the US, but I don't feel it's as much hull design difference as it is other factors. And as for your 30 Ron, I agree that it would easily run high teens if you bolted 400Rs on the transom. Might even go faster than that!
Here's a pic of an XCAT DW from the back...Goldcoast
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