MyChron4 w/ e-Box vs MyChron5 GPS

I’ve been using a My4 with e-Box, speed sensor and timing beacon forever, which has provided data that is consistent and useable. What I find most useful for tuning and improving driving is time comparison and splits from session to session or sessions from another day. So overlaying is important, which the My4 set-up does perfectly. I’d like to go with the My5 but my experience with GPS and the MY4 wasn’t good because that the time data had to be manipulated to overlay properly with data from another session, which doesn’t invoke a lot of confidence that the data is good. A couple of questions to those using My5:

  1. Are the session overlays with the My5-GPS perfect from session to session?
  2. Can a My5 w/ GPS also run timing off a beacon?
  3. Are there other strong reasons to move to a My5-GPS?
  4. Is the track position data useful in the My5-GPS?
  1. Yes. As a test, I just overlaid the same track, two years apart. Except for slightly different driving lines, the traces did line up. I haven’t figured out how to insert jpeg photos into a post on this forum.
  2. Yes, but believe the GPS has to be turned off. Check w/ AIM support.
  3. I think so. The accuracy of the M5-GPS is much better. It uses two satellite systems in stead of one used by the M4.
  4. That would be up to you.
    Don’t quote on this, but I believe that you can connect your existing e-box to the M5. Downloading data with the M5 is wireless. Also when downloading the M5, there is an option to save a second copy of the data as a backup. An extra bonus is the M5 comes preloaded with tracks from around the world and are managed by RS3. No separate GPS management program. With the M5, will have to give up RS2.

Fwiw, just a few days ago on a Youtube thread, Ryan Norberg said this re Mychron 4 vs 5 when asked about it (he was using a Mychron 4 at this years Supernats), " I prefer the 4. The data is much more accurate".

GPS can still be on when using the IR Beacon.

Also, to post photos, when I am on my computer, I just drag and drop the photo in.

Thanks Michael Z. That’s a lot easier than putting a photo on a public server and then adding the link to my post. And that should exceed the minimum 20 characters required for a post.


Yeah having externally linked images only for them to get taken down by photowhatever drove me nuts when looking at topics on forums.

If you’re on mobile you can use this “upload” icon at the bottom


I have both and use the 5 because you just bolt it on and go…Its very easy.

  1. Usually yes, but very often I use the laborious ‘GPS lap insert’ function to correct data between sessions which lines it up very well.
  2. I’m pretty sure you can and in conjunction with GPS
  3. Mychron 5 GPS data is way better than Mychron 4 GPS like Larry says.
  4. Hmmm, not sure, I’m often tempted to use it to explain things to drivers but always with the caveat that I don’t fully trust it. It gives us clues that we talk about but I don’t use it as a definitive measure.

The 5 isn’t compatible with the eBox which is a terrible shame. I’d prefer to have the ebox option but honestly with the mychron5 I haven’t missed having a wheel speed sensor all that much. Wheel speed has plenty of potential for inaccuracies itself. I don’t miss having to make sure the wheel speed sensor and magnets are all fitted and functioning, especially in changing conditions.

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The big advantage for me to use gps instead of beacon is that i can add sektors for the track. We have here some tracks with only one stripe on the start finish. So i can add mor to compare the sectors on the track

With the My4 and a speed pickup, the track can be split up into segments.