ODMBA Record Trials

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Who would have thought that we would have gotten the water conditions we did when Friday night that pond was getting shredded by 40+mph winds. We actually started getting some fairly decent water late Saturday afternoon but Sunday was THE day, can you say the calm AFTER the storm? :) I sure am glad I took today off 'cause I'm still tired but very happy as we all did well. Like John mentioned a BIG thanks to Steve Sutton for spending so much time manning the clock as it gave the rest of us time to be really focused on the tasks at hand. And also a special mention to Mr. Finch for the many tosses of the twin as I know your shoulder must be sore today, thanks John! Now it's time to clean up the boats and the shop then start gearing up for a couple winter projects. Thanks again to everyone, I had a great time. B)
Guys this was the best record trails event I have attended in 10 years. I have not seen the water lay down like it did on Sunday at one of these events ever. I enjoyed seeing all of the minds working hard to help one another to achive the results / records they were attempting to beat. I saw some extremely fast boats and was in awe of the sounds and speeds Mr. Porter was able to obtain in two of the Tunnel boat classes, his engines really sounded wicked. Mr. Finch showed me some intresting tech design on his scratch built mono which let this little 20 mono run over 77mph really amazing. Like has been mention before Mr. Ferrette's Twin was absolutely awesome and to watch this boat run at 109.80 mph on one of the passes was incredible. Mr. Hall's little Wild Thing / Extreme Thing turn up so many rpm's I thought the engine was gonna blow up, and the boat was wickly fast. Mr. Todd Anderson's Gas Mono ran really well and broke the record but the engine let go in some additional passes so we could not tech the engine he was pushing / knocking on the door of the 50 mph mark with this Homelite engine nice job Todd even if you didin't get and offical record. Last but not least as I have know this guy for many years and I just keep learning things about mono's and set ups from him Mr. Speas Stone Stock 23 Zen in this special set up 46" Twincraft was awesome reaching a speed of 55.40 mph I watched and helped Mr. Speas and Mr. Finch wrench / adjust several things on this boat with in 3-4 passes Steve reached the 55.40 mph mark which was amazing to see with this small stock gas engine. I would like to thank Steve Speas, Preston Hall, Todd Anderson and Christy Hibbert for helping and witnessing the recorded times obsevered on the timing equipment. Had a great time and maybe I'll have something to run next year with all of the information I got over the weekend. Great Job and Congrats to all of the New Record Holders.
 
congratulations to everyone on their new records. having met some of you at the hagerstown race, makes it a little more meaningful for me. sounds like a good job by all, racers and workers.
 
Kentley,

Great job last weekend,would you care to share some information on the #1 propeller?

I have had a lot of people ask me about it, so I thought I would ask you. My guess

would be a Octura V-937/3? Now is it time to go play with the Browning firearms?

Kentley,

Your engine RPM was aprox. 34,762 RPM!!! WHAT A BEAUTIFUL SOUND!!!

Thanks,

Mark Sholund
 
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Here is the link to the YouTube video of one of Don's record passes with his twin-

 
Thanks for posting that KP. I don't have speakers here at work so I'll have to wait 'til I get home to hear the audio. :D

I noticed you also got the video up for one of your & John's 20 mono runs, bad little ride. B)

Kentley & John's 20 mono-

 
Here is the link to the YouTube video of one of Don's record passes with his twin-


Just got home to watch & hear it with the audio this time, too cool. FWIW that was one of the early passes about mid morning with the sun to our backs, I think that was when we first busted the record. I stopped at that point to have the stroke checked on both motors, then set about upping it from there. By day's end we tacked about 10 more mph on. B)
 
GREAT STUFF guys!

And thanks for sharing the vids.

Those little Novarossis are really smokin,

But Dons twin,wow! What a great sound! Those Macs sounded like one. Gotta love em!

Very impressive vids and a job well done guys.

It's way.............. harder that it looks,that's for sure. :)
 
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Kentley,
Great job last weekend,would you care to share some information on the #1 propeller?

I have had a lot of people ask me about it, so I thought I would ask you. My guess

would be a Octura V-937/3? Now is it time to go play with the Browning firearms?

Kentley,

Your engine RPM was aprox. 34,762 RPM!!! WHAT A BEAUTIFUL SOUND!!!

Thanks,

Mark Sholund

Mark,

You are soooo Funny.................... You have a tach in your ear???? :lol: :lol: :lol: :lol:

TB
 
Bill,

Just doing some simple math on my web site.

Propeller efficency is the key on any great running boat.

20% Slippage is pretty close in our testing.

I would bet that I am pretty close on the actual RPM if it

was that propeller?

John,

I have a tach also,but I always wonder how accurate it is?

The math seems to be a easier way to go figure.

Thanks For Reading Fellas,

Mark Sholund
 
You can use a sound tach to figure out the rpm. I have one that was made from scratch but it doesn'tGo past 30,000 rpm. For real!
John,

What processor [chip]did you use in your audio tach to compensate for the doppler effect of the audio signal coming back from a moving boat?

I have been trying to find out how to do that for years.

I can get past the 30K problem but I have never been able to solve the doppler effect problem.

I'm sure there is a way to do it but to date I haven't been able to find out what it takes to do it. :wacko:

Do you have a schematic for the tach?

Thanks,

Rod Geraghty
 
You can use a sound tach to figure out the rpm. I have one that was made from scratch but it doesn'tGo past 30,000 rpm. For real!
John,

What processor [chip]did you use in your audio tach to compensate for the doppler effect of the audio signal coming back from a moving boat?

I have been trying to find out how to do that for years.

I can get past the 30K problem but I have never been able to solve the doppler effect problem.

I'm sure there is a way to do it but to date I haven't been able to find out what it takes to do it. :wacko:

Do you have a schematic for the tach?

Thanks,

Rod Geraghty
What if you sample the frequency when the boat is at 90 degrees to you?
 
What processor [chip]did you use in your audio tach to compensate for the doppler effect of the audio signal coming back from a moving boat?I have been trying to find out how to do that for years.

I can get past the 30K problem but I have never been able to solve the doppler effect problem.

I'm sure there is a way to do it but to date I haven't been able to find out what it takes to do it. :wacko:
This page has the formulas http://hyperphysics.phy-astr.gsu.edu/hbase/sound/dopp.html . Just program them into a spreadsheet on a laptop and you'll be able to quickly adjust for speed and temp. As was noted, when the boat is directly in front of you, the doppler effect is 0. As it is leaving and approaching this point, it is relatively small.
 
You can use a sound tach to figure out the rpm. I have one that was made from scratch but it doesn'tGo past 30,000 rpm. For real!
John,

What processor [chip]did you use in your audio tach to compensate for the doppler effect of the audio signal coming back from a moving boat?

I have been trying to find out how to do that for years.

I can get past the 30K problem but I have never been able to solve the doppler effect problem.

I'm sure there is a way to do it but to date I haven't been able to find out what it takes to do it. :wacko:

Do you have a schematic for the tach?

Thanks,

Rod Geraghty
What if you sample the frequency when the boat is at 90 degrees to you?
At 75 mph a boat is traveling 110 feet per second.The audio tachs I have seen have a one second sample rate or 1/3rd of the length of the trap at 75 mph.Depending where you are standing on the bank that one second could easily be 30 to 45 degrees off center.

In the past I have tried taking samples 2-3-4 times off a boat I know is traveling virtually the same speed on each run and the rpm readings have varied from 10 to 14 percent.

Obviously my audio tach leaves a lot to be desired and I was just wondering how Johns was made.His may have a much quicker sample rate so getting a rpm reading right in front is possible.
 
My tach is no better than yours Rod. I always used 21 percent slippage to figure my mono hulls and that has always been right on. I think the formula is most accurate. Just keep going shorter on the pipe and see how far you can go. The 20 mono came up too quick at the pipe length that took the boat to 77mph. The reason I gradually got to speed was to try and keep the pipe from coming on too hard, which blows the boat off the water. I think a little longer pond and a quarter inch shorter on the pipe will put the boat into the 80 mph range, because Kentley's engines will turn more than what they did at the trials. I have heard his Orlic engines stage 3 times. Awesome stuff. Maybe Bob Morton will have his lake ready for next year. That would be a great place to see it happen. Or should I say HEAR it happen.
 
My tach is no better than yours Rod. I always used 21 percent slippage to figure my mono hulls and that has always been right on. I think the formula is most accurate. Just keep going shorter on the pipe and see how far you can go. The 20 mono came up too quick at the pipe length that took the boat to 77mph. The reason I gradually got to speed was to try and keep the pipe from coming on too hard, which blows the boat off the water. I think a little longer pond and a quarter inch shorter on the pipe will put the boat into the 80 mph range, because Kentley's engines will turn more than what they did at the trials. I have heard his Orlic engines stage 3 times. Awesome stuff. Maybe Bob Morton will have his lake ready for next year. That would be a great place to see it happen. Or should I say HEAR it happen.

Ya'll come up to Flint next year and maybe it'll stage 5 times... :lol:

https://www.intlwaters.com/gallery/displayimage...m=551&pos=1
 
You can use a sound tach to figure out the rpm. I have one that was made from scratch but it doesn'tGo past 30,000 rpm. For real!
John,

What processor [chip]did you use in your audio tach to compensate for the doppler effect of the audio signal coming back from a moving boat?

I have been trying to find out how to do that for years.

I can get past the 30K problem but I have never been able to solve the doppler effect problem.

I'm sure there is a way to do it but to date I haven't been able to find out what it takes to do it. :wacko:

Do you have a schematic for the tach?

Thanks,

Rod Geraghty

That's a simple answer Roddney! Just run along side the boat!! LOL :)
 
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