40,000 rpm........what's the problem

[Fluid]

It depends on the hull design. Keeping a boat on the water is a balance of lift versus weight. The PT SS45 is a great example, sport hydros are not cats. It was originally designed with lots of lift to go, at most, 50 mph (this from Phil himself). As we began increasing the speed with FE components, the aero lift became an issue as speeds passed 65 mph. The front tabs helped, but so did the weight of NiMH cells (24 in the case of a club member's 65+ mph record holder about 8 years ago). For SAWs the weight does not hurt, as long as there is sufficient runup and slow down room on the pond. You just have to start your run deeper....

When we went to lighter LiPo power, the lower weight hurt boat stability at speed. Phil did some hull re-design which helped, but the lift/weight physics can't be overcome with strut settings alone - not on this hull at least. It amazes me to see the SS45 exceeding 100 mph, and I know it wasn't easy to get there ($$$). Our club oval races three of them, and they are in the high-60s/low-70s in race water running 6S2P. The 2P weight helps, but they still can blow over. What we need are hulls specifically designed for 70+ mph, then weight could be reduced for better performance on oval and on shorter SAW ponds. But so far, no Q-sized hulls seem to get there. The newest ML boats seem closest, but what we really need for higher speeds are sport hydros which look more like riggers - the Insane sport hydros come to mind. But then purists would wring their hands and cry foul......


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[kfxguy]

Hmmmm. This is very interesting.

[grsboats]

Definetively the type of hull plays a big role in this subject.I only run riggers(heat and saw) and they are different animals than hydro ports,cats or tunnels.My boats don't carry too much weight and run in the mid 80's effortesly with in budget motors like Leo'and TP's.For those that never experienced these hulls can be difficult to understand but light is better.Remember the way a rigger planes at high speed with its front over sponsons as the transom is carried by the propellor,mainly lift ones.Agreed that right balance is a rule of thumb for every class but we are talking of low lift to no ground effect hulls that are placed on the top of efficiency.Just my two cents Gill

[Doug Smock]

The bigger box pictured was full of lead pieces from 2oz to 6oz a year ago. It was all confiscated by D3,D5, D12,& D13, FE Oval & SAW racers. It's valuable a tool, and very easy to use. Especially for those of us that don't understand the dynamics involved in high performance model boat racing.

DSCF5743.jpg

[kfxguy]

The bigger box pictured was full of lead pieces from 2oz to 6oz a year ago. It was all confiscated by D3,D5, D12,& D13, FE Oval & SAW racers. It's valuable a tool, and very easy to use. Especially for those of us that don't understand the dynamics involved in high performance model boat racing.

[ATTACH=CONFIG]116025[/ATTACH]

Is that....is that weight...you add to a boat...no no no...it can't be. Why would you do that? You must be like me and not understand what really keeps a boat on the water (gravity maybe?). Ok my foolishness is over. Doug, I'm glad you posted this. I was thinking for a little while that maybe I need to get out of this hobby because I didn't know what I was doing. You changed my mind. I'll now continue on my learning path. :)

[kfxguy]

Definetively the type of hull plays a big role in this subject.I only run riggers(heat and saw) and they are different animals than hydro ports,cats or tunnels.My boats don't carry too much weight and run in the mid 80's effortesly with in budget motors like Leo'and TP's.For those that never experienced these hulls can be difficult to understand but light is better.Remember the way a rigger planes at high speed with its front over sponsons as the transom is carried by the propellor,mainly lift ones.Agreed that right balance is a rule of thumb for every class but we are talking of low lift to no ground effect hulls that are placed on the top of efficiency.Just my two cents Gill

Gill, i know those riggers are light. I've seen those run and they are a totally different animal. Wicked fast and agile. I need one in my life lol.

[Doug Smock]

Doug, I'm glad you posted this. I was thinking for a little while that maybe I need to get out of this hobby because I didn't know what I was doing. You changed my mind. I'll now continue on my learning path. :)

Well then Travis my job here is done! Really glad I threw you the lifeline!

Before I get hung up to dry by the hydro guys. I've never added weight to my riggers. Apparently anyone can set those up.

[Gary]

Fluid excellent views and opinions. Thats why I always go to you for help and your part of the reason my boat is as fast as it goes.

Gill... the first time I picked up a full size rigger I could not believe how light it was. I would love to build one but my PT45 took three years to get there and I just couldn't start on a hull I no nothing about...AGAIN LOL

[kfxguy]

Well then Travis my job here is done! Really glad I threw you the lifeline!

Before I get hung up to dry by the hydro guys. I've never added weight to my riggers. Apparently anyone can set those up.

Thanks doug! Lol....like I've told you before..you Tha man!

[kfxguy]

Fluid excellent views and opinions. Thats why I always go to you for help and your part of the reason my boat is as fast as it goes.

Gill... the first time I picked up a full size rigger I could not believe how light it was. I would love to build one but my PT45 took three years to get there and I just couldn't start on a hull I no nothing about...AGAIN LOL

A rigger is possibly my next project. I want an all carbon fiber one of course. If anyone knows a good one to get, throw me a bone (link lol)

[flraptor07]

A rigger is possibly my next project. I want an all carbon fiber one of course. If anyone knows a good one to get, throw me a bone (link lol)

I'd look real close at these,http://forums.offshoreelectrics.com/...iber-4S-Rigger and Randy's a great guy to deal with. I got one of his SS 30 Sport hydros coming now..

[keithbradley]

The bigger box pictured was full of lead pieces from 2oz to 6oz a year ago. It was all confiscated by D3,D5, D12,& D13, FE Oval & SAW racers. It's valuable a tool, and very easy to use. Especially for those of us that don't understand the dynamics involved in high performance model boat racing.

[ATTACH=CONFIG]116025[/ATTACH]

Your confiscating lead? Why?
I have lead weights on the wheels of my car doug, but it's not because they need to be heavier. I can only assume anything you're taking off a SAW boat is from a rigger or hydro where there was not enough room to find the proper balance naturally.

[keithbradley]

Jay: I understand what you're saying in regards to lift, but would you agree that lift is a function of hull design and therefore can be addressed at the bottom of the hull, topside, drive angle, etc?

Travis: If gravity is what's keeping your boat on the water, what's keeping planes in the air?

[Doug Smock]

Your confiscating lead? Why?
I have lead weights on the wheels of my car doug, but it's not because they need to be heavier. I can only assume anything you're taking off a SAW boat is from a rigger or hydro where there was not enough room to find the proper balance naturally.

Better re read the post Keith.

[keithbradley]

Better re read the post Keith.

lol. Yeah it makes more sense the other way around.

I was trying to imagine a situation where you would be confiscating people's gear and couldn't make sense of it.