Tuning Tools

Misc Article... by Carlo Catalanotto


Some good tips on tools that can be very useful for tuning your boats...

GPS, Radar Gun, Stopwatch, Tachometer

I have seen debates about all of these items and which is the best way to tune your boat on all the popular forums and the truth is that none of them are the one perfect gadget. All of the items mentioned in the title can be valuable tools when used correctly, but you must remember that these are only tools that give you information and if you don’t know what to do with the information then these are all useless. None of these are going to make your boat any faster by themselves, but knowing what to do with the info they give you is the real secret to setting up a fast boat. I am fortunate enough to have and use all of these to set up boats and will give you my opinion on each of them.


If you just want to know the top speed of your boat then the GPS is perfect for doing that. It is accurate simple to use and you can do the testing without assistance from anyone else as you simply place it in your boat and go run. They are inexpensive and will at least let etrexyou know the speeds you are seeing. It is one of my favorite tools and if you use it correctly and watch what your boat is doing around the course and through the corners it can help choose a prop or a setup that will work well on your boat. If you are making a simple pipe adjustment or changing to a prop with a little more pitch then just a few laps and you have an answer.  I think the GPS works great and have helped me get many boats dialed in and up to speed.

My experience with the GPS units is that if you are going to use one then use the big yellow E-Trex unit as it always seems to be dead on compared to the little green Gecko ones that I have personally seen give false numbers on more then one occasion. If you are using it to help tune your heat race boat then make sure to drive at a slow speed to you are on the course before letting it rip as to not give you any readings that could be from a long run up.

Radar Gun

The radar gun is also useful if you want to use it to get corner speed or Straight away speeds as a reference for your boat. I am of the belief that if you are going to use one correctly that it will need to be mounted on a tripod to be at all accurate for comparison type of testing. In all of the testing that I have done I have found it to be less accurate then the GPS when standing on the shoreline holding it220_1159991720 in your hand. Unless you are standing directly in front or behind the boat while testing the readings will vary from any angle that the radar gun is submitted to. How many times have you seen a guy following the boat as it goes by with the radar gun? They are designed for reading a straight line coming directly at or away from the gun and any angles or movement will affect the reading. I still think this a good tool and used correctly can help you make tuning decisions that can help make your boat faster.

My experience with the radar gun is that there is way too much movement and angles for any kind of comparison testing unless it is mounted stationary for your testing. Mount it on a tripod have someone take notes each time you make a lap of the speeds being recorded and make changes accordingly to increase the speed and it is a great tool.

Stopwatch/Timed Course

The next thing that is becoming the most talked about testing tool is the stopwatch. It is also my least favorite among the list. I am a firm believer in lap times and consider this the best way to truly know how fast a boat is around the course. When used correctly a timed course will let you know what lanes on the course are the fastest for your style boat. It will let you know what prop is getting you around the course the fastest no matter what the top MPH is and it will let you know what adjustments are making your boat faster around the course.

stopwatchMy experience with a stopwatch is that the human element of the testing is way too inconsistent. To think that a person controlling the stopwatch is going to be accurate within a few tenths of a second each lap is unrealistic as it can vary as much as three tenths of a second or more. Excitement, adrenaline and nerves among other things when testing a new part or setup can easily effect how fast or slow the triggerman is on the stopwatch. Then there is the driver factor that you have to add to the equation. If a driver is trying to compare props or setups and makes a lap in lane 1-1/2 instead of lane 1 or over shoots a corner just a little and has to drive back to correct then all of this will make a huge difference in lap times. If the information from the lap times has varied because of one or more of these reasons combined and you are using this information to tune and adjust your boat then you can easily make poor choices. In my opinion there are just way too many variables when using a stopwatch by hand and it is because of these potential inconsistencies that the handheld stopwatch is my least favorite way of testing. . If you have access to a timed course to tune your boat with some sort of transponder system or timing lights then this is one of the best ways to tune your boat.


A tachometer is a great tool to monitor what your engine is doing while going around the course. It can also help you make slight imager.phptuning adjustments (Pipe, Carb) and see if the changes you have made are in the right direction. It is also one of those items that by itself is not going to give you a lot of information, but combined with a GPS or one of the other items mentioned can give you information about what your prop or set up is doing in relation to the engine.

My experience with the tachometer in a boat is that when used correctly it can be a great tool for tuning your engine and helping to choose the right prop or setup. Once you have your boat dialed in and have a baseline it is great for monitoring the health of your engine after each run and possibly letting you know something is wrong before major engine damage occurs.


The best advice I can give with all of these tools would be to use the ones that you are comfortable with to help you get your boat dialed in. There is not one magic tool that is going to turn your boat into a screamer all by itself. The more information you can obtain from the any of these items the better off you will be.

Carlo “CC”  Catalanotto



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Moofy07 replied the topic: #11320 12 years 1 month ago
I agree with those two pieces (speed and revs)there is no human error to comprimise the end result.
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marc replied the topic: #11307 12 years 1 month ago
I like my old faithful Garmin Etrex and Sendec Tach. :)

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