Whats the "speed of distruction"?

[Varooom]

I realize all hulls and builds are different, with that said is there speed that crash damage starts to increase?

When I say crashing I mean blowovers, and flips, not crashing into something.

I have fliped my Revolt without damage a few time's because the fastest it has gone is 48 mph. I dont believe it is fast enough to be damaged by a flip (or blowover).

Is there a "rule of thumb" as to when a flip will usually result in damage?

I am guessing the magic number is around 60. Slower than that you are probably safe, faster than 60 is carnage.

What do you guys think?

Thanks for you time,
varoom

[Darin Jordan]

It obviously depends on the structure of the hull (how solid have you built things), but for your average boat, you get much over 45mph and things start getting damaged. A good solid flip on an IM31 will compress the deck down and pop seams, etc. Bending rudders, trim-tabs, etc. happens as well.

The guys that go 70+ at the SAW events multiple times with the same boat, after having survived the testing/tuning process, build their boats out of very solid, usually heavier layups, use stainless steel knife blade rudders, hardened props, etc...

[Shooter]

Ask my Lucas brother, John. He seems to get there often.

[properchopper]

YES ! Thank you for asking this question, easily one of the most important issues in FE to be examined given the almost universal quest to gofaster. It can be reduced to examining the relationship between increasing one's boat speed vs. the "price one pays" for such an accomplishment.

There's two basic ways to gofaster. One is to assemble a dedicated, well built, and often high-dollar rig to SAW competition standards. The other, as most frequently evidenced here, is to up-mod an existing design, often (but not necessarily always)a rtr.

To bolster my argument I'll use an example where I'll risk some deserved criticism from the accuracy police, but bear with me. Consider this :

For a moment, picture yourself the owner of a full size sportboat - let's say a 32' catamaran that does, say, 60 - 70 actual mph from the maker. Now drop in two 1000 horsepower funny car motors from John Force Racing. The boat can theoretically go well over 200 mph. Ask yourself this : Would you climb aboard and go for a WFO cruise?

Now, take a 32" FE cat and prop it/overvolt it to do well over 200 mph scale speed (I know, I know - How is scale speed really determined?). Point is that the FE boat at crazy speeds which far exceed the design/original intent speed don't stand much of a chance to remain stable OR survive the very predictable breakage.

Plus, remember that 60mph you're doing 88 feet/second. In four seconds you're more than a football field away. if the boat makes it. I've seen most ( not all, but most) of the videos of gofaster FE boats being sport run with at most 2-3 seconds of wide open throttle. Is that enough of a reward for putting your rig at risk ?
Some might say yes, but it's a point to ponder.

Getting to an answer to the OP's question, I'll agree that 60mph is, at least for me, the "safe and fun" zone. As a point of reference, my two run-for-fun boats are my Cheetah which is a 60mph rig which can be made to go much faster but can be run reliably for a few minutes at that speed without issues in handling or reliability, and my Jersey Skiff which goes maybe 35-40mph but is a total fun/gigglefest boat and one of my all-time favorites. OH, and I do have some faster boats I race, but are cut from a very different mold.

Just some points to ponder........, but GOOD TOPIC

Tony
[email protected]

[keithbradley]

I agree with both Tony and Darin. With a RTR style boat, you'll start entering the danger zone somewhere are 45mph, and with custom built boats that number may be a bit higher (like the 60mph range that Tony mentioned). Some more expensive boats can be built to take a bit more abuse and crashes at much higher speeds are possible without significant damage. The key word here is "possible". There are a couple of factors that play into this:

First: The relationship between speed and energy is not 1:1. Energy = Mass * (speed*speed), not Mass * Speed. This means that the same boat going 100mph will not carry twice the energy as if it were going 50mph, it will carry 4times the energy. For this reason, the faster you go, the bigger difference you will see in damage from an increase in speed.

Second: The way you crash has everything to do with the damage you incur. A boat that stays in the air for a while will of course loose a lot of energy before it impacts the water. Furthermore, a boat that skips, tumbles, slides, etc. will not displace all of it's kinetic energy at once, it will be split into much smaller, less devastating doses. A boat that hits the water just right and instantly stops at 70mph will take a much harder hit than a boat that skips across the water at 90mph. If you're running on pavement with a RC car, for example, you never displace all of the kinetic energy you harness at once unless you hit something that doesn't move. Simply flipping on asphalt will slowly scrub off small amounts of energy through tumbling, sliding etc. In a boat, the water can create a much more brutal environment as it has the ability to stop the boat at once.

Once you get close to 100mph, it gets difficult to build a boat that will survive the perfect (in a negative sense) crash, no matter what you do.

[properchopper]

To, if I may, further illustrate Keith's point(s), the normal and expected trials and tribulations at an organized SAW time trial : ( please dokeep in mind that these boats are majorly dedicated hard core raceboats built and piloted by those with extensive background,knowledge and considerable investment whose goal is simply to keep the boat intact and waterbound for 330 feet through the traps)

https://www.facebook.com/photo.php?v=697450810273839&oid=448732121813569&saved

Manuel W. from Austria demonstrating his Euro-Style "Whirling Dervish / Horizontal-Spin Dismount" to help in dissipating impact:

https://www.youtube.com/watch?v=QI9iR8d3Wyo

And to borrow a term from Jon Stewart, your very SAW "Moment of Zen":

DSC05246-1.JPG

[iridebikes247]

Sometimes people crash at 105 mph nothing happens, not even the RX pack pops loose and after a once over you're back on the water in 5 minutes. Sometimes a 75 mph crash blows the seam on a 1000$ hull though. Some guys get lucky and crash at 90-100 mph A LOT and nothing happens (provided everything is built and secured perfectly). so as some of the other guys one here said damage incurred has to do with the particular crash and if the boat skips a bunch of times before making contact or if its the dreaded dead stop. Nothing is bulletproof but the more time and money you spend acquiring quality parts the better the chance you've got.