Nitro tuning?
 

I hear you guys talking about RPM while its running at WOT....How are you guys determining the RPM???.....By hearing it or is there a device that you use???
Also how are you getting your GPS speeds???..Its not like you can put a handheld in the boat...:)

RE: Nitro tuning?
 

SWAG! ;)
Why not put it in the boat? There's usually lots of spare room, just need to protect from water.

RE: Nitro tuning?
 

SWAG??????[sm=confused.gif]

RE: Nitro tuning?
 

Perhaps I should have said "educated guess". :D

RE: Nitro tuning?
 

[sm=lol.gif]

RE: Nitro tuning?
 

Calculate it using boat speed, prop pitch and the prop slippage factor. If the gear ratio is not 1:1 this also must be factored in.

Most are 100% water proof. I use the Garmin Geko. It weighs 3.1oz with batteries and is about 4 inches long. It fits in every boat I have dealt with. It has also been in a few planes as well.

Ryan

RE: Nitro tuning?
 

When you use a GPS to measure speed is there just a function that you record top speed with? Is there such a thing as a GPS with a TX and RX so that you can see the display on shore? Also about how much does one need to spend to get one that is accurate enough that you can detect relatively minor increases in speed that you gain from tweaking things?

RE: Nitro tuning?
 

I would think a radar gun would be the best way.....Even adding the little weight you do with a small handheld it may effect balance......JMO though.... [sm=wink_smile.gif]

RE: Nitro tuning?
 

Yea, I use a Garmin eTrex Vista and it weighs it down a lot. I can tell it leans. I just add one or two MPH roughly.

RE: Nitro tuning?
 

IMO, GPS is better. I've tried using radar and it is very tough to get it to recognize that something is moving. It has to be coming directly towards the gun holder. LOL Plus it only records max speed while your wife or friend is holding it.:) GPS records max speed from launch to bringing it in.

Many people just throw the GPS in anywhere not even thinking about balance and they never notice any differences. I also don't believe 3.1oz is slowing me down. I have done some experimenting with only giving myself 6oz of fuel and then another run with a full 12 oz. Runs were within .5 of a km/h ( .31mph )
My boat weighs 12oz lighter when my tank dries up, I don't believe the 3.1oz's of the Geko has any effect on it in any way.
If you are worried about balance just place the GPS over the CofG of the boat.

1. Find a GPS that records Maximum speed (not all do)
2. Not that I know of. Maybe the high end 2.4Ghz radio?
3. The Garmin etrex is cheap. Most GPS systems are accurate to +/-0.1mph. I would recommend getting the Geko as it is much smaller. Plus you can use it for other application, not just R/C.

Just for instance, if I have made 5 back to back runs, usually all of them will have different top speed readings. It may vary between 1km/h but its hard to repeat runs to the nearest .1mph.;)
Any changes you have made to the boat in terms of mods or adjustments can be easily recognized by the GPS. They are AMAZINGLY accurate!

Ryan

RE: Nitro tuning?
 

Eagle Tree makes a telemetry unit if I'm correct but I'm guessing that it's not cheap.
Using a GPS like the Gecko you need to have a pond or lake where you can make a good full throttle run, usually 300 feet or so to get an accurate reading.

RE: Nitro tuning?
 

Thanks for the info guys, it is appreciated. I am trying to go realitively low buck, so I will start shopping for a GPS that will record peak speed.

RE: Nitro tuning?
 

Try a Target store if you have one nearby, they've got good prices on GPS's.

RE: Nitro tuning?
 

I'd stronly recommend the Etrex or Geko from Garmin. They both record max speed along with many other features. Accuracy is .1mph. They also have a refresh rate of once per second.

This is what I have
http://www.target.com/gp/detail.html...sin=B00007MMNS

I paid $79.99 CANADIAN for it. The store I bought it from reduced the price because they came out with the Geko 301.

This is the cheaper larger brother.
http://www.target.com/gp/detail.html...sin=B00003WGP5

Ryan

RE: Nitro tuning?
 

I still go with the balance part would effect speed.......I know in our big boats we have to run ballast to get true #'s...Pad boats must be balanced properly to handle right and get proper speeds.....A boat that leans on pad is being robbed of speed....But i guess its the best you can do to get the #'s you want...;)

RE: Nitro tuning?
 

RC boats use weights for balance as well. All boats need to be balanced in order to find the appropriate COG. Once you have your boat completely balanced place the GPS system over the COG. By doing so, nothing in terms of balance/COG, will be changed! ;)

Ryan

RE: Nitro tuning?
 

Can you remove the casing? If the works is independent from the heavy plastic case, its smaller and lighter - and would probably fit under a lexan cover of a radio box.

RE: Nitro tuning?
 

That would be cool, to always have a gps on your boat like that! By doing that you would surly take away the waterproofing that the case provides, but that would be kinda cool.

RE: Nitro tuning?
 

Not that I know of. There are also too many risks involved.

Three ounces of weight should not be an issue. Size does limit things but since the GPS is waterproof you can put it anywhere you wish.

Ryan