70 mph Insane Hydro ?

[knpc]

I've been running my Insane hydro with a 1515/1y (x545) on 4s running ovals in the low 60s mph. I wanted to see what the hull was capable and if I could get to 70mph. I tried an v937 on 5s but couldn't get the boat to settle down. Today I tried a x442 on 5s and got 68.6mph . I was able to run w.o.t. the first few passes until the water got chopped up, then it got a bit loose. I ran about 8-10 passes and everything came back under 120deg. I can go up a prop and probably get 70 but am not sure how to settle the boat a bit. What do you saw guys adjust when pushing for higher speeds? Add wieght, adjust strut, adjust turn fin? I ran it twice, probably 18-20 passes total, and it never crashed or blew over. If I go up in prop I will certainly decrease the number of passes, I know it was alot.

Thanks
Kevin

[britscoot]

Hey Kevin

I ran on 5s today also but used a 2000kv castle and a H5 prop
It was fast!
Good to hear your 2200 came in with good temps.
I will be trying my 1515 1y next week.

Cheers

[m4a1usr]

SAW hulls normally do not run a turn fin. Since SAW is typically straight line passes. And some things to check for high speed is,1) play in your servo linkage. There should be absolutely none. 2) Sharp and I mean dangerous sharp rudder edge, sharpened equaly on both sides and the back needs to be square. 3) Strut depth and angle need to be close to perfect. That is obvious but what is perfect for the FE30? COB can be critical but I dont own one yet so I dont have the answer what the layout should be. Theres much more but others with more experience will need to chime in.

John

[Fluid]

FE SAW competitors seldom make more than 2-3 passes then bring the boat in. Hydros in particular need smooth water to reach the highest speeds - the sponsons will float above the water surface for the absolute minimum drag. This cannot happen with rough chopped up water. I have no doubt that the FE-30 can hit the 90s on 4S with the right setup and smooth water. The Whip did it years ago.

The best prop for beginners is probably the v900 series. This is a lifting prop so the strut needs to be dead flat, with around 35% to 40% of the boat's weight on the prop. They take a while to hook up and stabilize, but set up right they are very very fast.



.

[knpc]

Thanks John and Jay. I will make some adjustments and try with the turn fin off next time. I will have to add some weight to the rear for the v937, it kept hopping and blowing out last time I tried it even with the strut perfectly flat. The c.o.g. has been 2.75'' behind the sponson for the runs so far.

With it running so well and coming back cool on a x442, would a m445 be another logical prop to try? it runs right at sixty with this prop on 4s.

This is the fastest I've ever run a boat, it definately gets the blood flowing driving a boat at close to 70mph.


Kevin

[dana]

Thanks John and Jay. I will make some adjustments and try with the turn fin off next time. I will have to add some weight to the rear for the v937, it kept hopping and blowing out last time I tried it even with the strut perfectly flat. The c.o.g. has been 2.75'' behind the sponson for the runs so far.

With it running so well and coming back cool on a x442, would a m445 be another logical prop to try? it runs right at sixty with this prop on 4s.

This is the fastest I've ever run a boat, it definately gets the blood flowing driving a boat at close to 70mph.


Kevin

[Fluid]

With it running so well and coming back cool on a x442, would a m445 be another logical prop to try? it runs right at sixty with this prop on 4s.

You'd probably be better off with an x642. More pitch, enough diameter. Up from that would be an m645.

Try moving the pack back with the v937 to put more weight on the prop. You have lots of room to move that pack. Flip the motor over and gain another inch under the motor wires.






.

[electric]

Just did a quick run with my FE30 on a highly modded m447 prop. The eagletree gps let me down so I did not get a good mph. Peak Amps where at 179 with the average in the low 100's. I hope to get another run and get a speed, but I must say, everytime I run this boat I am simply amazed at how fast it is going and how stable it is. Without question the most solid boat I have owned to date.

[andym]

Amps are on the money Electric, the V series props stop hopping by rounding the ears and .020 back cut. Still a handful on most hulls doing circuits but that aggressive lift will be gone.

[carlcisneros]

If you can not move things back to get a bit more weight on the prop, get ahlod of one of the IV
bags the gas guys use for fuel (250ml would be good) and start adding water in it till it settles down to your liking.

Carl

[knpc]

I havn't had a chance to try the V-series prop again, but when I do I'll try moving my pack back and maybe adding some lead weight to the rear of the boat. I'm sure it's a balance of enough weight on the prop without making the front so light it blows over. If addidng weight doesn't help the hopping of the V 937/3 I'll try modding the prop as andym suggested.

I also have a X640,X642, M545, and M645 that I'd like to try on it as well. It was too windy this weekend to try to break 70, hopefully next weekend is calmer.

These are the props I have in my prop box if there are any other ones you guys think I should try.
x440
x442
x637
x445
m445
x640
x447/2
x447/3
x642
m545
x448
x450
v937/3
m645
x452
p230
x455
x648
x457


Kevin

[Fluid]

The problem with back cutting the v900 is you loose most of the trailing edge cup. Do that and you'd probably be better off with an X series prop as it slows the boat down. IMO if you can't get a stock v900 to work then don't bother modding it. They are great speed props as-is, proven on dozens of record holding SAW boats. They aren't the only way to get there, but they are a proven way.


.

[britscoot]

do you have enough props?.....lol

I was very happy with my Mark Sholund H5 prop until it got messed up by a mystery object.
Thanks for all your test results btw Kevin.
I am looking forward to finding out what prop you use to break 70.
I was up to 64.8 on a m445.

cheers

[britscoot]

Hey Kevin,
what is your strut setup?
Are you using a flat or round bottom?

[electric]

The problem with back cutting the v900 is you loose most of the trailing edge cup. Do that and you'd probably be better off with an X series prop as it slows the boat down. IMO if you can't get a stock v900 to work then don't bother modding it. They are great speed props as-is, proven on dozens of record holding SAW boats. They aren't the only way to get there, but they are a proven way.


.

What kind of props have you tried out to date and what speeds are you getting??