What’s Changing & Why
In 2026 COM is going to be upgrading our timing system to a transponder-based system that is compatible with AMB and Westhold transponders.
Our RFID-based system has served us well for many years, but moving to a transponder-based system will streamline our timing process as the transponders will work more reliably on all cars. The transponders also work reliably when multiple cars are crossing the start-finish line together (the RFID system requires line-of-sight, which would cause some cars to be missed).
What you need to do if you’re a student
If you’re a student with COM, there’s nothing you need to do! We’ll include a ‘free’ rental transponder in your event registration. While we don’t charge students for transponders, we do charge licensed drivers. You are welcome to buy a discounted transponder as part of this group buy–this is a great idea if you think you’ll be licensed in 2026!
Please note that you are obligated to return the transponder in good working condition. Transponders are due back by the end of the day. If a transponder or holder is damaged, the cost of up to $230 will be charged to your motorsportreg.com account.
If a transponder is not returned, your motorsportreg.com account will be charged $230 and you will then own it. You can purchase a $36 charger for it at a future event.
What you need to do if you’re a licensed competitor, instructor or staff
If you’re licensed, an instructor or staff, you must purchase a transponder.
Are the Westhold transponders subscription-free? Do they have a warranty?
Yes, all of the Westhold transponders are subscription-free (lifetime). They have a 3-year warranty, and the rechargeable units are designed to be serviced. Battery and box replacement cost for rechargeable units is $40 + freight. See https://shop.westhold.com/repairs/ for more info.
Are there mounting instructions?
Yes! See below for instructions and suggestions. We’ll update this document as we get more information.
Rechargeable Transponder Mounting Instructions
See this link for rechargeable transponder instructions:
https://www.westhold.com/docs/G3CAR.pdf
The SCCA Time Trials program also uses Westhold transponders, and they shared this helpful video on mounting : Transponder Basics | SCCA Shop Manual presented by Hoosier
We’ve seen people mount them on their rear license plate area, attaching the clip below to a ‘fake’ license plate
We’ve been told the Mylaps/AMB transponder clip also works with the Westhold rechargeable transponder. This clip provides a nice way to securely mount the transponder:
https://www.ogracing.com/products/mylaps-tr2-transponder-mount
Hard-wired Transponder Mounting Instructions
Note that the hard-wired transponders have to be mounted horizontally with the label facing the track–this is quite different from the rechargeable Westhold transponder or all AMB transponders.
See this link for hardwired transponder instructions: https://www.westhold.com/docs/TXDP.pdf
Location Suggestion
We emailed our vendor a photo of the AMB transponder mounted in my Miata and asked where he’d mount a Westhold hardwired transponder. He suggested: It could be mounted in the circled area.
It doesn’t have to be perfectly parallel to the track–you just need the silver label pointed towards the track surface. Remember that AMB transponders get mounted vertically while Westhold hardwired transponders get mounted horizontally (with the label facing the track).
Examples of Transponder Mounting
https://www.inexseries.com/documents/2022-transponder-mounting-location.pdf
https://www.inexseries.com/documents/2025-summer-shootout-transponder-mounting-locations.pdf
(Note that the old rectangular rechargeable transponders need to be mounted with the label facing the track. The ones we’re getting need to be mounted vertically.)
I usually run more than one vehicle during the year, would I be able to use the same transponder and swap it back and forth?
Yes, you can easily swap the rechargeable units between cars. For the hard-wired transponder, you could put a connector on the wiring harness and use some sort of quick release fastener to secure the transponder.
If I have a AMB/Mylaps X2 transponder, will it work without a subscription?
Our understanding is that a AMB/Mylaps transponder with an expired subscription will not work. The subscription is handled in the transponder itself, not externally. AMB/Mylaps transponders with lifetime subscriptions will always work.
Are there other transponders that might work?
We’ve been told that the AMB/Mylaps 160 yellow karting transponder can work, if mounted very low. Your mileage may vary.
How is COM able to support both AMB/Mylaps and Westhold transponders?
We have purchased 2 decoders that connect to the timing loop. One of the decoders is from AMB/Mylaps and the other is from Westhold. This allows our members great flexibility if they already have an AMB/Mylaps transponder.
Will my Westhold transponder work with other organizations?
It depends on the other organization’s timing system setup. Westhold is not compatible with organizations that use only AMB/Mylaps. If the other organization has both a Westhold and AMB/Mylaps decoder, then your Westhold transponder will work with them.
If you want the most flexibility, we suggest buying a used AMB TranX260 transponder from a vendor like https://www.ebay.com/str/eastcoasttranspondersllc
If a competitor opts not to buy a transponder, what happens?
You’ll be required to rent a transponder if you do not own one. During event registration there will be an option available to rent a transponder, but inventory may be limited as we will give priority to students.
What to do if you have questions?
Send us an email at membership@comscc.org.