Speedo vs GPS

[VA Chris]

For those of you who use GPS on your boats what kind of variation have you found compared to your speedometer. I.E Speedo reads 50 when GPS says 44. I have heard that the water pressure speedos are notoriously inaccurate but by how much?

 

[Pat Goff]

I've seen them dead nuts on and I've seen them 15 mph off. I've seen GPS off too, the only thing I really trust is a radar gun.



What'll mess you up with a GPS is current.

 

[Bill McElroy]

How would current mess up a GPS when the speed is calculated by time and distance via sattellite triangulation???...you would think it would be just the opposite,...in that current would have more of an affect on the water pressure going into the pitot tube...making a speedo read either faster or slower depending if you're going upstream or down...



I don't know,...just wondering...but it seems like the GPS would be a lot more accurate since it wouldn't matter what kind of surface you're on..water or land or in the air....only time and distance would matter.

 

[TrepMan]

WOT my Speedo (its the pitot tube not the one built into the motor) says 28mph and my GPS says 30.5.

 

[Mark Hofman]

My speedometer will read 56 and my GPS will read 50.

 

[Barry Loos]

On the Ohio River, my speed can vary a couple of miles per hour depending on going with or against the current. My speedo's error proportionately increases with increased speed according to GPS. My Speedo is consistently 5 mph too fast at WOT.



Da Bear

 

[Scott Hammer TOXIC]

My speedo shows 24 at WOT. I kinda think I am going faster because when I poke my head over the windshield, my eyelids turn inside out.



TOXIC

 

[Tony Payne]

If you have time to look at the speedo or the GPS while driving...



You're not going nearly fast enough!!!!!

 

[Al Greco]

My Speedo will read 69 when my GPS reads 61 or 62. My buddy's Triton reads the other way -- Speedo says 58 and GPS is around 74 -77.

 

[Bill McElroy]

My GPS will say 69-70...and the speedo says "0"....lol

It's plugged......and I can't get it out,..and NO,..I'm not drilling it out,..and I've already tried the fish hook idea, and as far as I can put the hook in..it's open! It's plugged up somewhere else....but I don't need a speedo..give me my RPM's and a GPS and I'm fine! hahaha

 

[Brian Bell2]

Speedo reads about 4 mph faster than my GPS

 

[TOMMY RICH]

If you have a paddle wheel speedo...they are more accurate than the tubes that run on water pressure.

Mac....use an air hose...that'll Git-R-Out

 

[Jim B]

Mac, gps while more accurate then a water fed speedo can sometimes be very off given the "right" conditions. It calculates speed by distance over time as you know but since gps accuracy isnt spot on every time it recalculates your position( 1 per second) that position can be a little off and any random direction. So on a day with overcast skys say where your gps is a little more off then usual it can really affect the speed readings. I have seen mine off as much as 5mph at wide open compared to where i normally run( when its off it almost always reads faster then i can go). Normally they are pretty good and id say mine is 99% of the time but there are times when it just isnt. I have even had days where i can be sitting still( on land) and my lat/lon position will change every second as it recalculates. This type of stuff only happens to me on overcast and stormy days. When it comes to my speedo thats a joke, my motor is jacked up enough so thaqt the hole comes out of the water and i loose pressure so the speedo stops working past 3/4 throttle. Even though gps can have its moments its still better then a speedo.

 

[Bill McElroy]

LOL @ Tom Mac.......Ask Toxic How much LEAD is in that Sled!!! I had to throttle back and WAIT FOR HIM all weekend when they were here!! ahahahhaha....

 

[Pat Goff]

Tee...

Those paddle wheel speedos are garbage bud, they fail in days from installation.



None of them are worth the trouble.

 

[VA Chris]

Well it sounds like none of us will know how fast our boats are unless we pass a cop in cove shooting radar.



For the most part is seems like speedos are reading 10% to 15% on the high side if we can assume the gps is pretty accurate.

 

[Thomas Macaluso]

I

 

[TOMMY RICH]

I dunno Pat..the one I had on my old 94 Tracker read within 2 MPH of the GPS and never had a problem but, this new one with the tube clogs all the time. I guess I could say my speed is "fast enough"

 

[Richard Whittemore]

My speedo is within 2MPH of my GPS!!!

 

[Scott Hammer TOXIC]

Mac had to wait because that speed demon 929 of mine wanted to fly OUT of the water!!LOL!! I hit the over rev warning a couple of times!! I was content to leave my hemrhoids where they belong. Now you gotta admit, runnin the river 3 in mine 2 in yours, I kept up j-u-s-t fine!!LOL!! Them there big boat throwin waves slowed me down a lot!! My idea of success......I didn't break nuthin!! On me or the boat!!



TOXIC

 

[Steve Rizza]

I GPS mine with Treps at the rally.

Gps said 34.2--speedo said 34.



Then I snapped a drill bit off in the hole...now it says 0

 

[Carlos Hathcock III]

Tox, what about MY back Or my headache on Sunday!!!!!

BTW Wish i had a pic of Neeley flying up in the middle seat! He had that down pat!



Hey mac, lets get that thing fixed ya know. you are talking about my boat now, well almost HAHAHAHAHAHAHAAHAHAH



I need to ask the members here if I can still hang even though I have gone over to the dark side.....

 

[Richard Whittemore]

Steve R...



Why did you run a drill up your GPS Unit????



:>)

 

[Bill McElroy]

C4,..no problem....I need to find an air hose as TEE suggested and blow it out. But after a whole season of use and most of it in less than ideal conditions.....a plugged speedo tube and one loose screw from under the dash somewhere is all that I've had to tinker with......that boat is rock solid!! You're getting an AWESOME rig!! No worries Mate!!



Carry on!!

Mac

 

[TrepMan]

Geeze Carlos, first you trade you're old Nitro for another members last year, now you're trading up to another Members Ranger, what's for next year?? Trading that wrapped Ranger for my Tracker!!! BBWWWAAAA



Hey, are you getting the Wrap on it or just the regular ranger colors?



Mac - If someone buys your boat can they keep the S&T wrap on it??? that would be one WICKED collectors item!!! I could see putting that boat up on blocks and in 3-4 years when S&T the Movie comes out, Mac's walking down the red carpet in Hollywood - BAM up on e-bay the S&T boat goes and the bidding escallates to $100k!!!! WOO HOO!!!!

 

[Geo F]

My speedo reads ZERO and my gps is well...up to 26.7mph going down wind and current.

 

[Bill McElroy]

Trep,....yes,..he's keeping the wrap on it,..for as long as he wants. If, in 2-3 years (or even later), he decides he wants to take it off,..Ranger will take it off for him,..and put brand new carpet and seats in it,..all at no charge to him!! That company LOVES their customers and the prove it,..day in and day out,..year after year!!

 

[TrepMan]

Mac - That is a great deal!! Now if I get Ford to hire you, double your salary from GM, promote you to VP, and carry over your retirement benefits... Then you can do a S&T wrap on a 2005 Ford Freestyle wagon!!!! Hey how about a S&T wrapped Avalanche!!!

 

[Bill McElroy]

No deal with the Ford gig Trep...that kind of responsibility wouldn't allow time for hunting and fishing!!

I'd rather keep what I have now and go home every day at 2;30pm..LOL!!! Priorities y'know!! Thanks for the offer though.....



I already ran the wrapped Avalanche proposal by TM 3 yrs ago...they weren't interested. So just for grins I ran it by Ranger and they said.."Sure,..what model do you want?"....'nuff said!!

 

[Ken Neeley]

Ok...I gotta chime in here.



I prefer Speedo's....they fit better, keep me more snug, and prevent things from falling out while allowing me to show off my physique.

I highly recommend a Brazilian Wax before putting them on...gives you a nice, clean look.

 

[TrepMan]

Mac - Shame on the Avalance, especialy when you were driving Nitros! I used to see an Avalanche at the Atlanta BPS store hooked up to Nitros, would look SWEET matching wraps!! But alas, Tracker lost and Ranger won!! Now how about a Ford Ranger and a Ranger boat!!!



Neeley - MAN, did you ever get a real job again yet?? And I read your profile over at the guns site. MAN you look like CRAP for a 37 yearold, Geeze i'm older then you!!! BWWWWAAAAA

 

[Ken Neeley]

Got a job, running a car dealership.



And what do you mean I look like crap, Mr. Kosher Chicken-Legs!!!

 

[Steve Rizza]

Chicken legs my eye....



Those things wouldn't even make a decent wing-ding !!LOL

 

[TrepMan]

New or Used Car dealer Neeley? Got any used 200hp Merc/Ford wagons with the true Dual exhausts???



Thanks Steve!!! With Friends like you who needs enemys!!!! Ship me a case of Iron City, and maybe i'll forgive you!!!BBWWAAAAA

 

[Steve Rizza]

Is it legal to ship beer across state lines?



I would gladly send you some down.If I do you may notice a strange thing about Iron City..There are always a few empty bottles in every case..... ; )

 

[TrepMan]

Just in case the goberment is watching... Steve - it is NOT illegal to ship beer across state line, BUT it IS Illegal to ship beer (or any other alcohol) INTO Georgia, its a state law! Georgia will NOT allow free enterprise and out of state distributers, to effect the Liquor lobbys paid puppets in the legislator!!



Trep

 

[Steve Rizza]

Sounds as bad as our State run liquer stores.



I can only imagine the price of booze here private business were allowed to compete for our dollars.

 

[TrepMan]

We finaly this summer got the State to alow beer over 5% alcohol!! WOO HOO!!!

 

[Jim B]

Steve R is booze expensive where you live? Up here in Mass they tax the crap out of it and its very expensive. All the stores here in Mass are privately owned and have nothing to do with the state except taxes. What a lot of people here myself included do it go up to New Hampshire and get it there. The stores in N.H. are owned and run by the state up there but booze is like 25-30% cheaper then it is here.