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highest mph? (66 replies and 22 comments)

jackwilliam
7 years ago
jackwilliam 7 years ago

just wanted to start a friendly competition on who could achieve the highest speed that they possibly could, i personally have gotten 105mph before backing off of the throttle due to lack of space. i'd love to hear anybody elses numbers!

jackwilliam
6 years ago
jackwilliam 6 years ago

looked at this thread a few days ago and saw that piazz had beaten my score, somewhat jealous, i got back onto the game and tried to beat that although i couldn't manage anything over what i had gotten previously (115) looks like ill have to wait patiently for those mercury racing 400r's to come into the game to beat 116.

Todd Wasson
6 years ago
Todd Wasson 6 years ago

Would you guys be interested in an in-game leaderboard? That might make things a bit more fun. Maybe I could set up a couple pairs of buoys on Lotus Lake set some distance apart so it'd time you through a quarter mile or something to get an official speed.

If that sounds interesting, maybe it'd be a good idea too to do different classes so it's not all just about making some 14 footer with 300 hp. Maybe split things up by length and power so you've got a few classes like "18-19 foot 200 hp," that kind of thing? I want to add multiple engines too so bigger boats can be useful, so maybe "triple engine 24 foot 300 hp" class or something like that could be an option. 300 doesn't really cut it for the bigger boats..

Any ideas? What would you guys like to see there?

jackwilliam
6 years ago
jackwilliam 6 years ago

my vote?...YES TO ALL OF THAT

jackwilliam
6 years ago
jackwilliam 6 years ago

the game has been out for a little over a month now, just wondering on the progress of it..hows it coming along?

Todd Wasson
6 years ago
Todd Wasson 6 years ago

Since release I've been focused almost entirely on marketing and getting operations running smoothly (dealing with emails, trying to minimize refunds due to people with Mac's buying it, etc.), so not much has been done on the game side. It's amazing how much time the business side of things can take up. Yesterday I released a patch (1.201) to add the metric system so advertising can be done outside of the US soon.

On a perhaps more interesting note, this motion platform company contacted me about adding support:

<a href="http://www.simcraft.com/" rel="nofollow">http://www.simcraft.com/</a>

I want to do it. Can you imagine running this on a motion platform? With the big screens it'd be cool, but I'd really like to try it with the Oculus Rift on one of those platforms! I've got a Rift and it's really amazing with the game. Fighting a little chine walk while flying along on a motion platform in the Rift would be pretty mind blowing. 😀

Either way, some videos of it running on this would probably help spread the word and get some more players. The main problem at the moment is just getting exposure and sales. At the moment it's just trickling in and more than half the money is just going back into advertising.

jackwilliam
6 years ago
jackwilliam 6 years ago

i know that personally jumping right into the game i went for the 300hp outboard, i got back onto the game today to fiddle with the 150 and i wanted to know if anyone has really tried to get some decent numbers on the motor with their best speed hull...

I managed to get 86mph with a little hassle of prop selection, im sure this can be beat relatively easy but i wanted to maintain some "boatability" and make sure the boat can turn and handle jsut as well.

hope all is well todd, keep it up

Todd Wasson
6 years ago
Todd Wasson 6 years ago

I did this the other day too, tried a 150 and it seemed rather difficult to get enough bowlift at the lower speeds. I just got an email from somebody saying much the same thing, he's playing around with boats running in the 80 mph range and complained about a lack of aero lift.

I'm wondering if the boats in the simulator might be a tad too heavy. I'm not so sure we should be doing well over 100 with 14 footers. The current 116 mph record is coincidentally also the speed record for the world's fastest bassboat which is a good sign, but the Allison holding that record is a lot longer than 14 feet.

Maybe I need to lighten the boats a bit so to hit the really high speeds you'll need to be 18-21+ feet or so without it blowing over? Not too sure.

The boat weight is solved from the hull directly and is a function of surface area, so the small boats here are lighter. Lightening them would just be a matter of changing the "density" (really it's weight per unit surface area in the sim rather than volume). Maybe I ought to add two or three options there: Light, medium, heavy, for a bit more customization. Then for the hulls running in the 60-80 mph range or so you'd get enough bow lift on something closer to 18 feet.

Anyone have thoughts on this?

Todd Wasson
6 years ago
Todd Wasson 6 years ago

I've looked into this more and it looks like the boats here are indeed quite a bit too heavy. There are a lot of specs here on Hydrostreams and so on:

<a href="http://boatspecs.iboats.com/Hydrostream/bp/20br1233" rel="nofollow">http://boatspecs.iboats.com/Hydrostream/bp/20br1233</a>

Taking the default 18 foot DIDI_Boat1 example:

Dry weight: 1228 lbs
Total weight (dry weight + fuel + driver + engine) = 2018 lbs

Compare that 1228 lb dry weight to a few other boats:
15' Viper 570 lbs
17'1" Hydrostream Vector (1985) 640 lbs without passengers, fuel, or gear
17'9" Hydrostream Viking 625 lbs
17'11" Switzer Craft SK-175 Skier 900 lbs
20' Hydrostream Vulture 850 lbs without passengers, fuel, or gear
20'2" Allison 850-900 lbs
21'2" Allison XB-21 1280-1350 lb

My family had a Switzer Craft SK-175 growing up that did about 62 mph with almost no bowlift whatsoever, certainly no chine walk, and a comparably sized boat here in DIDI is about 36% heavier than that. So yeah, it looks like we're too heavy by a long shot...

The DIDI_Boat1 18 footer dry weight is about the same as the Allison 21 footer. If I increase the length of the boat to 21'2" the dry weight of the DIDI boat goes to 1438.

I'm looking into changing this to bring them more in line with real boats and display the dry and total weight onscreen somewhere while you're designing things. Mass property computation (mass, moments of inertia, center of gravity location) takes a long time to do so I didn't include any of that on the design screen originally. Otherwise you'd get a noticeable lag whenever you clicked a button. I've just changed this tonight so the weight is computed separately and the rest isn't computed until you actually leave the design screen. That's running fast enough so I'll probably include that in the next update.

I don't want to go so far as to have people entering in their own weights, but am considering an option for light/medium/heavy that you can use to tweak things to some degree and get closer to your favorite boats. Maybe what we have right now could be the "super heavy" option. 😛

Anyway, this might explain why everybody's getting away with little 14 footers. Once things are lightened up this probably won't work anymore, you'll need it to be longer to keep it from turning into an airplane. 🙂

jackwilliam
6 years ago
jackwilliam 6 years ago

honestly that sounds a lot better than what we have, the added weight of light medium and heavy sound nice but it should only be an indicator to the user, i don't think you should have it be a toggle for the layup of the boat because everyone would just pick the lightest layup to have the most efficient hull.
personally i think that prop pitch should effect more, on all of my speed hulls i'm running about 38-40 pitch props but how many actual boats are running this high of pitch? (they totally could be but i just haven't seen them)

jackwilliam
6 years ago

have you ever thought of adding aero impliments?
<a href="http://www.allisonboats.com/content/racing-boats/xr-2001/" rel="nofollow">http://www.allisonboats.com/content/racing-boats/xr-2001/</a>
for example in the third picture, adding a slope upto the engine instead of having the open bench seat for better aero. also having a closed cockpit for all out race, ive noticed in the simulator that the engine causes quite a lot of drag and i dont know if its because of the way the cowling is or not but anyway to reduce drag id be all for it

Todd Wasson
6 years ago
Todd Wasson 6 years ago

Props could be better, no question about that. At the moment each blade is just a single triangle so it's actually pretty amazing that it works as well as it does. Naturally such a simple design isn't terribly efficient, so things are raked more than they ought to be in order to get slip somewhat in the right ballpark. It's on the radar but will have to wait. I considered doing a much higher resolution version, but after analyzing it I realized that computationally it's tricky because the props are solved at very high rates (1000 per second or so, I think, would have to double check). So doing 4 triangles in the prop is the same as doing 40 in the boat. Doing 40 or 50 in the prop is like adding an entire extra boat into the mix.

This is to get good surfacing behavior. Without it being high enough you get wierd strobing effects with rotation. Long story, I'll spare the details. 😛

On the weights: I've been experimenting a bit with this and I'm not so sure people will always pick the lightest one. With a setting I've tried right now it's hard not to blow over at anything over about 70-75 mph with an 18 footer. Trim it up all the way and it'll go over at just over 60 mph. The little 14 footers don't even come close to that. Probably a bit on the light side then, but it just shows that lighter isn't always better. If your boat only weighed 10 pounds it wouldn't go 10mph before taking off, so you do need some weight there to hit any decent top speed. With this new setting I had to extend the boat to 24 feet to hit 95 mph.

I'm looking at center of gravity location too, trying to find an excuse to move it forward just a bit. Tiny changes in the CG position have a huge effect on all this too.

On top of this, I looked through bass boats and the hulls (dry weight) look like they're typically almost twice as heavy, so if somebody wanted to model something like a bass boat it'd certainly have to be a different weight. So I'm stilll leaning in the direction of having a weight option in there representing essentially how thick the fiberglass hull is.

I'm curious about blowover speeds in general though. I've read that a 15' Viper will blowover at 80 mph pretty easily even though people sometimes run them much faster than that. I could run our Switzercraft SK-175 at 60 mph with the engine trimmed up past maximum using the trailer button and it would just start to chine walk a little bit at most, it wouldn't blowover at that speed. I'm curious how many boats out there would blowover at 60 or 70 if they were trimmed up to 8 or 10 degrees, or if we shouldn't be getting that until 80 or 90. I'm curious what an Allison bassboat (the 116 mph record holder, I forget the model) could do at max trim before it went over assuming no wind or waves.

The weights are simple enough to get about right, but the CG location is critical to all this and I've only got one boat's data point on that. Comparing to that one our CG's are too far rearward, so probably lightening the boats and moving the CG forward a certain amount might get us closer to reality.

Aerodynamics of engine: Yes, there's a lot of drag on the engine and it creates a great deal of bowlift in the simulator. In fact that's the only part of the boat where I use a coefficient to reduce the forces on those polygons. Would have to double check but think it's at 0.50 right now. With it set to 1 the boats were too slow and a bit too "bow lift happy." I have considered adding aero devices too but it's a bit tricky to do given the procedural generation aspect of all this. While experimenting with the sim it became obvious that a shield over the engine would probably help a lot, then later I found that very thing on the Allisons.

What I need more of are speed targets especially regarding blowover and chine walk onset. I.e., how fast various boat sizes and types should go when chine walk starts in or the thing just blows over at max trim. I don't have enough experience with this and I don't know anybody who wants to run a boat at full trim and flip it just to report how fast he was going at the time for research purposes. 😀