Basic Overview of GPS Lap Timer Options
It’s time to start logging your consistency as a driver.
Let me preface this article by stating that this is strictly for evaluating solutions for basic data such as speed and GPS location for lap timing. This is what I typically recommend starting out with for newer HPDE participants who have a few events under their belt. They should be comfortable with the car near the limits, and looking to start tracking their consistency corner to corner and lap to lap. More advanced car data can be captured separately, and I personally like keeping the two somewhat separate as it means less to worry about focusing on while at the track.
I’m not sponsored by any of these manufacturers, and paid full retail price for everything. This is absolutely not an end-all-be-all article. There are better resources for focusing on driver development and data, and would recommend these as the authority on who to listen to:
Ross Bentley’s Speed Secrets: https://speedsecrets.com/
Krause & Associates LLC: https://www.peterkrause.net/
For this article I will mainly be commenting on the lap timer/GPS solutions that I have personally used:
Phone based Apps + external GPS
Aim Solo 2
Garmin Catalyst
Phone based Apps + external GPS
RaceChrono Pro with Qstarz BT818XT external GPS
Cost: ~$100
The cheapest way to get started logging GPS and speed is by using a phone app such as Harry’s Lap Timer, RaceChrono, TrackAddict or similar.
The one I actually used myself was RaceChrono Pro which cost me $20 to purchase, plus the BT818XT was an $80 external bluetooth GPS unit. The external GPS is highly advised: You want something with at least 10hz refresh rate, or it is able to update 10x per second. The phone’s built-in GPS is generally around 1hz for reference.
When I was looking for an app to try in 2021, I chose RaceChrono because it does have the ability to log some OBDII parameters, the most useful being throttle position. I was able to trigger my GoPro with the RaceChrono app which was great. It makes syncing video and making an overlay incredibly easy and fast.
My biggest gripe with a phone based app is that trying to sync everything up, start logging, while you might be getting a surprise text message or phone call from somebody as you’re about to go out on track. While I never used it with my GTI, there are several people who have extracted a lot more in-depth data using RaceChrono since you can input custom PIDs - which may come in handy later on for logging temps, throttle trace, etc.
AIM Solo 2
AIM Solo 2: Turn it on and it just plain works. Better yet it is easily transferrable from car to car, so you can compare vs your buddies.
Cost: ~$460 at the time of this writing
I used an AIM Solo 2 for several years. It’s not ridiculously priced, but is still notably more spendy than a phone app with external GPS. If you strictly want lap times only, and that is it, this is a very reliable solution.
Where the Solo 2 falls short is in AIM’s analytics interface: Racestudio. You must have a laptop with you at the track, and whenever you return from a session, download via Wifi to Racestudio. The software is a bit clunky, and unintuitive. You WILL figure it out with some time, watching a LOT of Youtube videos, and reading the AIM documentation. It can be a relatively quick process, but will take some time to get there.
If you want to overlay your speed and G-force data, it is a bit cumbersome but you can export it as a .csv to eventually merge over video via RaceRender. You can use RaceRender for free, but the free version has some caveats like 3min max clip length, a RaceRender logo must remain in your video, etc.
What the AIM Solo 2 taught me is that data is only useful if you look at it. There is only so much time in between sessions on track, usually chatting with buddies or trying to find something to eat, etc. I found myself repeatedly not analyzing any of the data beyond just “yep I did 87mph through South Bend that one time”. It is a very powerful tool if used to it’s fullest capabilities, but the learning curve is steep, and I found it lacking in the effort required vs benefit gained. I’m a “casual” track rat and I would find myself forgetting how to do XYZ operation when attempting to change the data to .csv to make it useable in RaceRender.
Note: There is also an AIM Solo 2 DL. It sells for ~$800 and has CAN bus logging capabilities down the road. It is still a LOT of expense that still requires merging with video when done, and time taken in between sessions. AIM sells a “SmartyCam” which is $900 and will sync with the AIM data seamlessly. At $1300+ out of pocket to get set up with a basic Solo 2 + SmartyCam, I didn’t deem it as a viable option. People who have spent the money do seem to love the setup though as it doesn’t require fiddling with overlays manually.
I am admittedly not entirely up to date on the many AIM products that have come out in the last few years, and if some of this sounds like what you want, then I would highly suggest giving Peter Krause a call or email via his contact info in the link at the top of this page.
Garmin Catalyst
Garmin Catalyst: a HUGE time saver in helping you find your greatest opportunities fast, but it’s a not-insignificant cost.
Cost: ~$1000
The Garmin Catalyst is an incredibly efficient tool to help you go faster… faster. The price was initially hard to swallow, but due to my aging GoPro Hero3 (yes, 10+ years old now) needing replaced, and the above mentioned data analysis inefficiency of the Solo 2, I took the plunge to try this device as an all-in-one deal.
In short: It has lived up to it’s expectations. You start the car up and it turns on automatically. You hit “Drive” and confirm or change a few things on the screen (dry or wet, driver name, vehicle, etc), and then it automatically starts recording at 30mph.
I use the Catalyst to review in between track sessions quickly and efficiently, leaving me time to stay hydrated and fed, cool off, or just relax. It identifies 3 opportunities to work on for the next time out, with video reference of what you need to keep doing, and you can use the “advanced race coach” to give you prompts/input while on track the next time out. My favorite part is the “optimal lap” video that it stitches together based off of all the sessions you’ve already done. It is a fantastic visual reference to watch a few times right before gearing up to get back out on track.
I could go on about it for a while, but it’s probably just best to see what Ross Bentley has to say about the Catalyst.
I use the Catalyst alone to actively monitor data over the weekend of the event, not even looking at my Simos Tools data logs until I get home. Well, maybe just a little peek if I can make the time or am testing something specific.
Aside from cost, the main downside of the Catalyst is that it’s not easily transferrable from car to car. The unit itself is, but the camera (which is auxillary to the main unit) gets sticky taped to the windshield. There are aftermarket suction cup mounts for it, though I do not have the need so cannot comment on their effectiveness.
In a nutshell the Catalyst is easily the best thing I’ve purchased for dropping lap times and making the most out of every session on track. There is a Catalyst App that you can sync your data to, and view speeds/G-forces/relative time overlaid from one lap vs another, or even against your friends’ laps if you add each other within the app.
It is not without it’s flaws: I have had a GPS glitch on a cloudy day that messed up my optimal lap (teleported 3 seconds further down the front straight) which could have happened with any data system, there was one update pushed that disabled sound by default (so my current fastest lap is without audio), and I found that when you come off track and it asks you “End session?” if you do NOT press anything and shut the car off, it will not save anything. All manageable and not the end of the world, and in my opinion the benefits far outweigh the few small issues I’ve had with it. There is a Garmin Catalyst Users group on Facebook which is a great resource if you happen to go this route.
