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Are radar guns accurate for boat speed?


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#1 StephenLilly

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Posted 27 September 2018 - 07:22 AM

Trying to decide between gps or radar gun? I know gps will work but it would be nice to just point and shoot with a radar gun and not have to take the time to remove tape from the hatch everytime to see speed. Making adjustments to look for improvements i.e. Prop change, trimming, leaning engine etc. on the spot would be much better with a radar gun if accurate. I see bushnell has one for around $50, about what I could get a cheap gps for. Thanks.



#2 John Beardslee

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Posted 27 September 2018 - 08:17 AM

Trying to decide between gps or radar gun? I know gps will work but it would be nice to just point and shoot with a radar gun and not have to take the time to remove tape from the hatch everytime to see speed. Making adjustments to look for improvements i.e. Prop change, trimming, leaning engine etc. on the spot would be much better with a radar gun if accurate. I see bushnell has one for around $50, about what I could get a cheap gps for. Thanks.


The older Bushnell guns didnt work well over water. Not sure about the newer ones.

Thanks John



#3 Grimracer

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Posted 27 September 2018 - 08:46 AM

our stalker works VERY well!

 

Grim



#4 PaulHail

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Posted 27 September 2018 - 10:20 AM

The word you're looking for is consistent.  Even if a radar reads 10% high or low, if you get consistent readings you'll know that you're tuning is going in the right or wrong direction.  On the flip side, if the readings vary from lap to lap by 10%, then it won't be useful to let you know if your tuning is helping or not as a faster run could be measured as slower if the device gives inconsistent readings.



#5 LohringMiller

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Posted 27 September 2018 - 12:22 PM

We did a lot of testing with radar, GPS and speed through traps.  The Garmin GPS peak speed was very close to to the peak radar speed in acceleration testing.  The early Eagle Tree GPS units had a slow update speed and always lagged the actual speeds.  The later units (2008) we ran in our electric hydro agreed well with the trap speeds and a GPS speedometer.  GPS is less expensive and would be my choice.

 

Lohring Miller



#6 Terry Keeley

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Posted 27 September 2018 - 12:40 PM

Eagle Tree!  You don't have any angle error and it tells the whole story, everywhere!

 

Get the Power Panel and you can see peek speed and rpm as soon as you bring in the boat.

 

http://www.eagletree...ategory&path=62



#7 aaron alberico

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Posted 27 September 2018 - 02:24 PM

We back to back testing the new Futaba 7PX radio (with GPS) against a stalker pro radar gun on my SAW 40 Hydro and very pass was the same or with in 1mph at passes up to 120mph...

Edited by aaron alberico, 27 September 2018 - 02:25 PM.


#8 Jim Allen

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Posted 27 September 2018 - 05:26 PM

Stephen,

I use a Stalker PRO radar gun. To get the most accurate reading possible the radar gun must be placed directly in line from the front or rear of the boat. We use a dedicated person stationed at the end of the lake with a TRC-236 transceiver which allows communication as each pass is made. Standing on the shore always produces a tangent error that is hard to calculate! We have also used this gun to check radar speed readings when compared to data logger speeds derived from a pylon racing plane. As long as the radar gun is in line with the object being tested, it will read correctly! The gun comes with a tuning fork for onsite calibration.

Jim Allen

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#9 dick jones

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Posted 27 September 2018 - 07:04 PM

Radar Guns VS ????????????

I have used radar guns, 4 different guns, over last 22 years, currently using a Stalker  pro 11, with the 4 targeting, switching modes , built in to the unit, which comes in very hand,y for different applications, what I like the most about the radar gun is the ability to capture the exit and entrance speeds in the corners. These numbers, represent the ability of the boat to accelerate out of a corner, and how fast it can accelerate to, "MAXIM SPEED",  before the next corner.

I would hate to guess, how many boat races I have been to over the last 35 years, but after watching and radaring most of the heats here I was attending, the corners, and straight away speeds, will defiantly help a driver, if he knows this info, while practicing!!

JM2Cents

dick jones 



#10 Andy Brown

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Posted 27 September 2018 - 08:02 PM

We back to back testing the new Futaba 7PX radio (with GPS) against a stalker pro radar gun on my SAW 40 Hydro and very pass was the same or with in 1mph at passes up to 120mph...

 

We back to back testing the new Futaba 7PX radio (with GPS) against a stalker pro radar gun on my SAW 40 Hydro and very pass was the same or with in 1mph at passes up to 120mph...

 

....So what happened after 120mph? Lol



#11 aaron alberico

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Posted 27 September 2018 - 08:21 PM


We back to back testing the new Futaba 7PX radio (with GPS) against a stalker pro radar gun on my SAW 40 Hydro and very pass was the same or with in 1mph at passes up to 120mph...

 

We back to back testing the new Futaba 7PX radio (with GPS) against a stalker pro radar gun on my SAW 40 Hydro and very pass was the same or with in 1mph at passes up to 120mph...

 
....So what happened after 120mph? Lol

Andy were we test the lake is little small as soon as you hit the pipe your pretty much have to let off after couple seconds (no wind out) for the run down, we run straight towards us.

#12 John Finch

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Posted 28 September 2018 - 05:18 AM

Stalker radar gun is the way to go. Like Jim said.  Straight on with the boat coming at you or going away.  I have been using mine  for about 20 years and it is spot on.  If you want to have fun and not prepping for record trials leave it at home or you will spend hours upon hours trying for that next mph.  It is the fastest lap that wins races so for heat racing use a stop watch.

 

John



#13 LohringMiller

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Posted 28 September 2018 - 10:20 AM

The learning curve is steep but with the Eagle Tree you get the whole story.  It tells you the speed, position, and rpm all around the course.  Below is one lap with an electric mono at the Electric Nationals.  I find it embarrassing to plot my actual path around a course.  It also shows how curved your "straight line" was through the traps at a SAW event.  With electrics you can find the input volts and amps as well.  Below is the plot from our 98+ mph UIM record run.  The volts and amps are from one pack.  The volts to the motor are 6 times the values on the graph and the amps are 7 times as much.  The peak was over 800 amps.  It's notable that lithium polymer cells don't pull down much with high currents.

 

Lohring Miller

 

Attached File  Untitled.jpg   71.32KB   5 downloads

Attached File  UIM runs.JPG   86.06KB   5 downloads



#14 Carl Van Houten

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Posted 01 October 2018 - 08:12 PM

We have used our Stalker for the past 20 years and it does a great job once you get used to driving straight towards it.



#15 Jimmy Boatright

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Posted 04 October 2018 - 06:29 PM

We back to back testing the new Futaba 7PX radio (with GPS) against a stalker pro radar gun on my SAW 40 Hydro and very pass was the same or with in 1mph at passes up to 120mph...

GPS sensor and is it version 1 or 2? Thanks