Video of JAE21

[shoboat]

Marty,

It is going to need to be aprox. 84mm of pitch or 3.3" to get into the 80's

at 35,000 RPM with about 25% slippage. We are currently working on

a different propeller project to go close to 90 MPH with a lot less slippage.

We have it down to 6% slippage so far, and more testing to come soon.

I will post more when we have the next set of prototypes ready to test.

Thanks,

Mark Sholund

 

[LarryConrad]

Awesome video Aaron! The boat looks great on the water, and the sound of that high revving Nova is like sweet music to my ears!

 

[Tim Kish]

Very nice Aaron the sound is dead on.

Kently were's my boat ??????

Tim K

Zippkits, in stock.

Can't work with wood anymore , alergic to the dust ended up in hospital a couple times before I figured it out

.

Tim K

 

[Ron Zaker Jr]

Very nice Aaron the sound is dead on.

Kently were's my boat ??????

Tim K

Zippkits, in stock.

Can't work with wood anymore , alergic to the dust ended up in hospital a couple times before I figured it out

.

Tim K

CD Machine (David Pruesse) well worth the fee! Do it man!

 

[Marty Davis]

Marty,

It is going to need to be aprox. 84mm of pitch or 3.3" to get into the 80's

at 35,000 RPM with about 25% slippage. We are currently working on

a different propeller project to go close to 90 MPH with a lot less slippage.

We have it down to 6% slippage so far, and more testing to come soon.

I will post more when we have the next set of prototypes ready to test.

Thanks,

Mark Sholund

Mark:

So you supplied the prop that he was running in the video?

Tell us a little about the prop if you will.

Thats a big gain from 25% to 6% :blink:

 

[Tim_Duggan]

Who said those carbon fibre SPP pipes and Nova 3 ex port motors don't work.........

I am supposed to race against this thing in a few weeks. I know mine isn't running 80mph, not even in the trailer on the freeway. I might have to scratch mine and be a spectator instead. Video rarely does a fast boat justice.

 

[aaron alberico]

Marty

NO!!! I do all my own propellers, Mark had nothing to do with this boat.

The boat launched real easy, on that video it was not thrown well and I was adjusting the steering the for first couple of laps,

if I had more time I would have propped up a little. In smooth water I think it would be even better.

Marty/Mark

As you know, a boat can only go as fast as the leading edge pitch x rpm's,

so if you know how much LE pitch you are running and the speed you are doing you can work it out.

The modified propeller I was running has 2.42 in of LE pitch and the boat was doing low 80mph, so

the LEAST rpm's I would have to run that speed is 34900rpm, it was most likely doing more.

The pipe is S.P.P NR special that we have been working with.

Dont forget this was the first time I put this boat in the water,

it was blowing about 25mph winds and there was rough water...

regards Aaron

 

[mtruex]

Marty,

It is going to need to be aprox. 84mm of pitch or 3.3" to get into the 80's

at 35,000 RPM with about 25% slippage. We are currently working on

a different propeller project to go close to 90 MPH with a lot less slippage.

We have it down to 6% slippage so far, and more testing to come soon.

I will post more when we have the next set of prototypes ready to test.

Thanks,

Mark Sholund

mark, if that is true i need to try one

 

[Tim_Duggan]

I can't understand if you guys aren't logging rpm and speed at the same time in the boat for each run then why slip figures are nothing more than an educated guess and shouldn't be considered a constant.

Hypothesizing an rpm by speed and the mysterious slip figure seems somewhat flawed to me. What am I missing?

 

[mtruex]

I can't understand if you guys aren't logging rpm and speed at the same time in the boat for each run then why slip figures are nothing more than an educated guess and shouldn't be considered a constant.

Hypothesizing an rpm by speed and the mysterious slip figure seems somewhat flawed to me. What am I missing?

i agree, without knowing rpm and speed, slippage is just a guess..even with both i would think it would be hard to nail down a number, because of the difference in pitch from tounge to trailing edge? i guess it doesnt really matter anyway, if it sounds better and goes faster it is better!!

 

[Tim_Duggan]

i guess it doesnt really matter anyway, if it sounds better and goes faster it is better!!

True that!

 

[Marty Davis]

I can't understand if you guys aren't logging rpm and speed at the same time in the boat for each run then why slip figures are nothing more than an educated guess and shouldn't be considered a constant.

Hypothesizing an rpm by speed and the mysterious slip figure seems somewhat flawed to me. What am I missing?

Tim:

I AGREE 100% with your post. Slip is so elusive but it is interesting to talk about. I remember that Andy Brown always preached that the leading edge pitch was the control of speed. Guess his accomplishments lend credibility to that.

I can't wait for the NEW 6% slip props, that are coming

 

[Tim Kish]

If the radar gun says it's running over 80mph then thats good enough for me , anyone who has been in this hobby long enough knows that a good Radar gun means a hell of alot more than calculating pitch , slip and rpm .

I think Terry said it the best you can't bull **** a good radar gun.

Great boat Aaron and Kentley

Tim K

 

[Tim_Duggan]

It's also hard to bullsh1t a fastest class heat time on a measured course at a big race. Radar guns are great tools but in oval racing it's the first boat to finish the required race distance that matters, and thats not always the radar gun hero..... right Aaron?

 

[aaron alberico]

Tim

spot on buddy...

its the first one to cross that line B)

looking forward to catching up with you guy's

in couple of weeks

regards Aaron

 

[Terry Keeley]

If the radar gun says it's running over 80mph then thats good enough for me , anyone who has been in this hobby long enough knows that a good Radar gun means a hell of alot more than calculating pitch , slip and rpm .

I think Terry said it the best you can't bull **** a good radar gun.

Great boat Aaron and Kently

Tim K

LOL! BTW I call my Stalker Pro my "BS Eliminator".

I think Andy was bang on with his theory that the boat will only go as fast as the LE pitch, we've found that to be very true - at least with low drag hulls.

Nice runnin' boat! C'mon back in Tim, the water's great!

 

[shoboat]

Boaters,

Have fun testing this weekend.

Thanks,

Mark Sholund

 

[Jeff Lutz]

If the radar gun says it's running over 80mph then thats good enough for me , anyone who has been in this hobby long enough knows that a good Radar gun means a hell of alot more than calculating pitch , slip and rpm .

I think Terry said it the best you can't bull **** a good radar gun.

Great boat Aaron and Kently

Tim K

LOL! BTW I call my Stalker Pro my "BS Eliminator".

I think Andy was bang on with his theory that the boat will only go as fast as the LE pitch, we've found that to be very true - at least with low drag hulls.

Nice runnin' boat! C'mon back in Tim, the water's great!

Andy's theory???? Mercury racing would tell you the same thing. Not knocking Andy,but in model boating it seems if people learn something from some one they assume they are the discoverer.

 

[Tom Foley]

Great thread , awesome rigger Aaron .

 

[Marty Davis]

If the radar gun says it's running over 80mph then thats good enough for me , anyone who has been in this hobby long enough knows that a good Radar gun means a hell of alot more than calculating pitch , slip and rpm .

I think Terry said it the best you can't bull **** a good radar gun.

Great boat Aaron and Kently

Tim K

LOL! BTW I call my Stalker Pro my "BS Eliminator".

I think Andy was bang on with his theory that the boat will only go as fast as the LE pitch, we've found that to be very true - at least with low drag hulls.

Nice runnin' boat! C'mon back in Tim, the water's great!

Andy's theory???? Mercury racing would tell you the same thing. Not knocking Andy,but in model boating it seems if people learn something from some one they assume they are the discoverer.

Jeff:

You are probably correct about that. Check my post, I didn't say that Andy came up with that theory, just that he talked about it. The big boats and the toy boats sometimes run in a paralell universe. Really doesn't matter who came up with it unless the person saying they did objects. Knowlege is what is important and I really don't care where it comes from. Andy is just the first person that I had heard talk about the leading edge pitch being the limiting factor for SAW. I have know for a long time that cutting the tongue off of an X series prop did a lot to eliminate the governor effect of the tongue. I have seen Mercury MArine props for MANY years with aboslutely no tongue (like our V series Octura Props). I bet that Tom Preschenka would say that he copied that from Mercury MArine.