Sure. You have two other options for lap times./counting s/f passes…
One is an infrared beam from a mychron beacon box, often on a tripod at the start/finish line, along with a receiver on the kart that plugs into the mychron.
Another is a magnetic strip that goes on the track. This is less common though.
Here’s what the beacon box looks like.
There’s a good chance the track already has one and you may just need the infrared receiver on your kart.
Oh.
Okay so I actually have two sets of data I can reference, mine shows 1.25m average on the days the time did show correctly, the days it shows inaccurately the accuracy average is 2.51m.
For reference I have data from a next kart using a Mychron 5 and the accuracy says 0.424m average.
If you’re referencing GPS accuracy (the 1.25 or 2.51) it sounds like a lack of enough satellites. I work in the geospatial world and it takes time for a GPS receiver to ‘find’ enough satellites to get an accurate location fix. Generally, the more the merrier. By any chance, were there trees nearby when the accuracy was 2.51m? Did you turn the Mychron on and go? Just a couple of GPS related things I could think of that might affect the accuracy of the fix.
Hey David, yes GPS accuracy was referenced.
The days when I have this issue there is average 8-11 satellites available, but I’ve also seen it read correctly on other days with the same amount.
Yes our track is surrounded by a lot of trees, there’s probably a 100ft radius at most and 10ft at it’s least around the track that is clear, beyond that there’s a lot of trees.
No, I usually turn on the kart, MC4 powers on I wait a couple seconds to ensure that it does read what track it’s at before I drive off.
Currently my GPS module is mounted on the chrome bracket that’s between the steering column and the nose flare, see photo. Do you think an alternate placement would assist in a better reading? If not do you have any suggestions?
Also note the greenery in the back…yep that’s trees lol.
My hero 7 and 9 mostly fail at properly recording GPS. Dunno why it’s so fickle. It may be due to NJMP proximity to airport.
One question - thinking on it if my 5 does the same it does it if I’ve forgotten for example to switch it on before starting up the kart. When I start the kart it comes alive automatically, but I do find if I do that and set off right away as one does, it doesn’t get chance to initialise properly. Then it goofs up.
If I power it up then do helmet and gloves etc, by the time I’m in the kart it’s properly initialised.
Same thing happens with planes - you can’t just switch on and go, you have to wait 2-5 minutes for the gps systems to initialise and get the plane’s location pin pointed.
I think you’re setting off before it’s got you with enough accuracy. If it’s direct powered, you should be able to switch on the Mychron before you switch on the kart, as I do.
In theory. In my case, it doesn’t synch most of the time and the gps map comes out looking like a Jackson Pollock.
Is it the synch or the refresh rate? My Garnin watch is a bit like that but it’s because the GPS refresh rate isn’t terribly quick. . It’s a sailing watch after all, doesn’t need to be.
Jackson Pollock hahaha 
I think it has to do with airport and satellites. It’s probably a local
Phenomenon.
Nice pic! Generally you want to have the satellite antenna with the best view of the sky possible. Looks like you got that covered. If you’re getting 8-13 satellites with a good signal (high in the sky, not too close to the horizon) you should be fine. It’s when trees or buildings or other obstacles obscure the view of the horizon or you haven’t turned the unit on for awhile (or you moved some distance from where it was the last time it was on) that it could take some time for the GPS receiver to know where all the satellites should be. If a MC5 is getting a half meter accuracy, the WAAS processing (improved accuracy) is probably turned on. That’s something you might check on your unit. Hope all that is of some help!
I think this might be a critical factor!
Usually when I turn get off the track and turn off the kart/MC4 at the scales, it’s then moved on the stand to my tent and then back to the pre-grid when I restart the kart/MC4. So maybe this can be the problem.
However as I said before, I usually ensure it initializes and recognizes the track on the screen before I drive off. Do you think I should leave it a bit longer still before driving off?
Yes, you’re giving it time to know where you are but not enough to fine tune your location. Just try giving it 30 seconds or so to figure out where it is.
Noted. Will do, hopefully this solves it.
Another note, since my data shows one long session rather than multiple laps, is there anyway to retroactively correct this in RS Analysis? I thought loading the track map would have…it didn’t lol.
You might be able to use beacon shift in Race Studio: Ask any questions about karting data analysis using Race Studio - #53 by Eric_Gunderson
Turning it on earlier may allow the unit to see more satellites before you go on track and improve the location accuracy. I’d try that to see if it makes a difference. Once you’ve turned the unit on the first time and you get an accurate fix, you should be fine the rest of the day. You’ll generally run into the issue with slow lock when the unit has been off for awhile or has moved a significant distance - a hundred miles or so. The Almanac (tells the unit where the satellites should be - makes startup faster) will be out of date (if it’s off for awhile) or won’t have the right satellite ephemera (if it moved a long distance since it was shut off) in those cases. That data is downloaded while the unit is trying to get a lock on available satellites.
Even the high end GPS units we used for field data collection had to be turned on half an hour or so before we needed an accurate fix if we had taken them any significant distance from the office.
Hope that helps!
Okay will check out this later tonight- thanks!
Also @Deanbert appreciate all the help- I’ll definitely try turning it on earlier next time I’m at the track and let you guys know. Thanks a lot also.
If you go to the GPS Lap Insert feature, you can set a start/finish line manually on the GPS generated track map, and confirming that start/finish line will automatically generate and split up all the laps correctly.
Have you taken the time to set your GPS to the Start/Finish Line? I also run the MC4 and frequent 2 different tracks. I still often have to tell it which track I am at. I had to set the GPS start/finish for both tracks before it would give me good data. Its not always easy during an open practice session with other karts whizzing by as you sit there. I suggest going out on a slow day and park the kart so that your beacon is directly over the start/finish line and recalibrate the point. It may take several minutes, but well worth it. I think on the mc5 and rs3, they improved this with base maps that have already done that.
