Jump to content

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

Speedometers


WakeGirl

Recommended Posts

Between the hubby & I, we've been on & around a few different boats recently, & I don't think that any of them had a way of calibrating their speedos (or the know-how via timer). Many of them were waaaaaay off, & it got me thinking about some of the claims that I've seen on this site as well as others as to speed, wake quality at certain speeds, etc etc. Perfect Pass isn't perfect out of the box either, ours was over 5mph off when we picked up the boat & thus needed calibrating as well. Also, the old 100 rpms per mph is generally good for ski speeds, but doesn't necessarily hold true at boarding or top end speeds. So, how many of you out there actually calibrate your speedos, including Perfect Pass, either by GPS or timer?

Link to comment

Timer. Though I'd love to check it against a GPS if anyone is gonna have one at Oroville. I went to Best Buy today looking for the $100 Garmin e-Trex and they didn't have any. Mad.gif The least expensive one they had was ~$300. I don't need one that bad. :(

Link to comment

We calibrated both the speedo and PP with GPS...thanks to Edwin. Speedo & PP were pretty close at our normal running speeds 28 & 34.2, but PP was way off at some slower speeds.

Link to comment
Timer.  Though I'd love to check it against a GPS if anyone is gonna have one at Oroville.  I went to Best Buy today looking for the $100 Garmin e-Trex and they didn't have any. Mad.gif The least expensive one they had was ~$300.  I don't need one that bad. :(

Bought mine at Circuit City. Here is the link. Currently selling for $94.99.

http://www.circuitcity.com/ssm/Garmin-eTre...roductDetail.do

Link to comment

I have a GPS speedo now, but still cal the factory speedo to the GPS... Even though I haven't had any problems wit the GPS, I still feel good about having a mechanical gauge... Problem is that mechanical gauges (including paddle wheels in my experience) are only accurate within pretty narrow speed ranges. In general, I've found that I have to calibrate at board speeds, again at ski speeds, and again a footing speeds if I really want to keep the stock needle accurate.

Luckily calibrating takes all of a second...

Phil

Link to comment

My speedo says that my top speed is 60... Origionally it never went that fast, but now that I've adjusted it, I can do 60 easily Thumbup.gif

... ok- I use a GPS, and it lives in the boat too - Michael, we can calibrate you this weekend if you want. I've found that neither the PP or speedo is accurate across the entire speed range. I use the pitot speedo for skiing speeds, and PP for wake speeds - they are both calebrated at those speed ranges.

Link to comment

Has anyone had a problem with GPS NOT being accurate? We set our speedos through the slalom course, using the magnets, so I know it has to be accurate. But a friend has a GPS handheld that says I"m going 1-1.5mph slower than what the times are telling me? Is this possible?

Link to comment
Has anyone had a problem with GPS NOT being accurate?  We set our speedos through the slalom course, using the magnets, so I know it has to be accurate.  But a friend has a GPS handheld that says I"m going 1-1.5mph slower than what the times are telling me?  Is this possible?

It would not be beyond the realm of possibilty for a handheld GPS to be off by that much at 36 or so MPH. Especially if it doesn't have "differential" capability, as I suspect many cheaper handhelds do not.

You don't have some cables attached to the buoys to stretch the course out a little, do you?

Link to comment

I also used my handheld GPS to calibrate the PP to wakebaord speeds so it is dead on. GPS is really the only accurate way to measure speed on the boat acrross a variety of ranges with timing the course only working for ski speeds. Of course if yo uare on a river then you have to adjust for the water movement and average runs in opposite directions.

I for one am willing to do whatever it takes to make sure I am really wakebaording at 22.7 mph.

Link to comment

Actually you can use the course for any speed checking as long as you have a decent stopwatch. You just might have to do some math to figure out how long it should take you to travel course distance at 22.7mph! And I am way to lazy too do it for you!

rts, maybe I should lengthen the course, get my speedo set, ski, and then shorten the course up for a really hot speed for my friends!

Link to comment
Actually you can use the course for any speed checking as long as you have a decent stopwatch.  You just might have to do some math to figure out how long it should take you to travel course distance at 22.7mph!  And I am way to lazy too do it for you!

Excellent Point.

My ideal wakeboard speed is 22.7 mph which is the same as 33.3 feet per second.

Assuming that a slalom course is 850 feet long then it should take about 25.5 seconds to drive the whole course.

I'll keep this in mind if I ever want to calibrate without a GPS.

Link to comment

I used a GPS to calibrate both the speedo and Perfect Pass. I had the GPS on my Christmas list for just this reason. My wife couldn't decide what GPS to get so I ended up with a BIG gift certificate to buy whatever I wanted. I ended up getting a Garmin Quest. It has a color display with downloadable maps. I bought the recreation lakes (and fishing hotspots) maps and downloaded the maps for all our local lakes. Now I have the channel markers and lots of other stuff on the display. A serious bit of overkill but fun. My wife used to worry about reading the contours of the lake to guestimate depths since the depth gauge is so erratic. Now she drives straight down the middle of the channel.....

Jeff/AirChair1

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...