sponson mod.

[TheShaughnessy]

If you had a particular hydro with a relatively low profile sponson is it feasible to mod the sponson to make it less susceptible to submarineing. I'm thinking something like what the UL1 has at the front of it's sponson.

I know the immediate answer is to buy a new hull, but that isn't really a financial option at the moment.

[domwilson]

Some have done it. Dumb question, but I have to ask...Have you played with the battery location, strut height and angle or even a different prop?

[m4a1usr]

Why modify the front of the sponson? If you know the AOA is not sufficient there are some options. You might be able to mod the ride pads with taper blocks. That in effect changes the ride angle, but not necessarily the aerodynamic effects. More detail could help us offer you some better advice.

John

[TheShaughnessy]

The problem is not so much the AOA as the boat wanting to sub. I have played with strut angle, a little bit with the height. A lot with the turn fin. So far I haven't tried anything other then a grim 42x 55. I had an m445 on it at one point with a spec motor but i was having the same issue.

In an attempt to keep all the Ms vegas info in the same place i have a posted all the info over here

http://www.rcuniverse.com/forum/m_4361937/mpage_159/tm.htm

username is asupervee72

[detox]

Heavier hulls need more ridepad height and width to get on plane quickly. My lighter weight 4s1p P Spec hydro Whiplash 20 jumps on plane instantly, but my heavier 4s2p P Sport Hydro Whiplash 20 submarined very easy if hull was not tossed. I have since built two more P Sport hydro Whips with raised and widened ridepads to cure problem of submarining (1/4" higher x 1/4" wider ridepads). The m445 should get hull on plane quickly.

If COG is too far forward hull will not get on plane easily.

[TheShaughnessy]

It gets on plane fine. It's what it does when it gets there that I'm concerned with.

[detox]

More ridepad height and width will help while running also. Especially in the turns.

[properchopper]

Mike, grab a seat and some Here's some food (popcorn) for thought. The Vegas has been offered in three incarnations. V 1&2 (you have V2) had a relatively shallow AoA. They convert sucessfully to high power FE applications like I did to it- you've seen the vid of your boat when I converted it doing 60+mph rather stably, and I've run it repeatedly with almost no problems nosing in. Once in a while it'd "catch a crab" but very infrequently - no more than other hydros. V3 was introduced as a Nitro with a smaller (.18) engine than V1&V2 and the AoA was increased to make it run faster with the smaller engine. Just like the UL-1 that has a relatively steep AoA to make it run high 40's with the stock 2030KV motor. BUT once pushed past that speed like the Iwannagofaster crowd does, the steeper AoA creates the dreaded sponson death dance. If you want to mod the sponsons for more AoA, you can do it relatively easily - kind of the reverse of what I did to my old UL-1 (which cured for the most part the dance once I pumped up the spec speed for P-Ltd Sport Hydro racing)- see photos.

Remember that, as has been posted here, strut angle, CG, and turn fin angle (and design) has tons to do with it - a turn fin is like a trim tab and will raise or suck down the sponson so attention to the fin (+ the other settings) need to be optimized.


DSC03098.JPG DSC03097.JPG

Now go get a chilled malt beveridge to wash down the

[TheShaughnessy]

Tony, I know, that's why I can't figure out why it wants to sub for me. I was not at all talking about AoA, but rather the front to back angle. So that if water hit the sponson it would want to stay ontop rather then digging in. But I realize this isn't the true issue. There are still lots of settings to try but subbing as hard as I am puts a ton of stress on the hull and I would like to avoid that as much as possible. That's all for now until further testing

[madmorgan]

hey chopper i watched your vid of the proboat conversion to fe i have a mv duece i converted over to fe i was wondering if you would know which hull is heavier ? ofcourse i did remove the rear wing on mine to lighten up the rearend a bunch.

[properchopper]

hey chopper i watched your vid of the proboat conversion to fe i have a mv duece i converted over to fe i was wondering if you would know which hull is heavier ? ofcourse i did remove the rear wing on mine to lighten up the rearend a bunch.

My conversion was done to the Vegas gen2, not the Proboat. The Proboat is @ 2"-3" or so shorter IIRC so it's probably lighter.