AIM Solo Data Logger Review
AIM Solo is my preferred portable data logger. I specifically bought it to use in cars other than my own - be those drivers I coached or drivers I hoped to learn from. I also use it when I drive my own cars for comparison data.
The distinguishing feature of Solo is its compactness and self-containedness. The logger is battery powered, although it can be connected to a 12 volt outlet for power. The GPS receiver is internal, requiring no wires. I attach Solo to the windshield facing rearwards using a Ram suction cup mount which is of excellent quality.
Solo has a backlight which I normally leave off to extend battery life. With the backlight off, I typically charge Solo before the weekend and the battery lasts the entire weekend without problems. As I instruct, on many weekends I datalog quite a few sessions.
Screen backlight is handy for evening and night sessions. I try to charge Solo overnight if I am using the backlight.
Solo compares favorably to using data acquisition software on a smartphone. Phones typically cannot run all day, much less a full weekend, with the screen on.
On the track, Solo just needs to be turned on and it will automatically record data when the vehicle it is in begins to move. Unlike smartphone applications there are no screens to go through. Because the operation is so simple, I often install Solo into various cars (by which I mean I stick the unit on the windshield) and the only instruction I give to the drivers is to press the power button when they are going on track.
Another advantage of Solo over a smartphone is that Solo's buttons are easily pressable in gloves, whereas depending on the phone it may be impossible to operate the phone with gloves on.
As with all satellite-based data acquisition systems, Solo needs a bit of time in the morning to find satellites. This is best done with the unit stationary and I typically turn the unit on at the same time I warm up the car.
Solo contains an internal database of tracks with their GPS coordinates. When the unit turns on, it will show a list of nearby tracks and prompt to select one if there are several (for example, as would be the case with NJMP Thunderbolt and Lightning). The last track used is pre-selected.
When Solo is at a new track it needs to be told where Start/Finish is. This procedure requires going through several screens, and the unit has a timeout on setting start/finish, but fortunately the procedure only needs to be done once per track.
Solo's display is small, both in size and in how much information it can display, but the unit's functions are similarly concise.
My default screen shows best lap time on top and real-time delta on the bottom. This is not a screen that comes pre-set in Solo but one that I configured because this is the data I want.
Automatic Data Overwriting
A displeasing aspect of Solo is its automatic overwriting of old data. The data is stored in a ring buffer, and when the memory is full the old data is silently overwritten with the new data. The unit provides no indication of how much memory is used up, or that it is overwriting old data. Depending on how much you drive, the memory can be used in about 10-20 days. I've had data overwritten dating back two months or so.
The solution to this problem is to retrieve the data soon after the weekend is over. Realistically it gets harder and harder to remember which session was what as time goes by, so this data retrieval practice is a good one to have.
Predictive Lap Time
Solo seems to require a full lap of data, start/finish to start/finish, to show predictive lap time. This means, in practice, that the first hot lap has no predictive lap timing, as often pit out is past start/finish line.
Racepak IQ3, in contrast, is able to show predictive lap time on the first hot lap.
Continuous Predictive Lap Time Delta
A feature that AIM data analysis software has has that Racepak software does not have is continuous time delta. Racepak software requires track segmentation and only shows deltas for each segment. In contrast, AIM data may be analyzed without ever setting up track segmentation (although AIM software does offer the segmentation option).
There are two versions of Solo: the Solo itself and Solo DL. Solo DL can connect to the car's ECU and - I imagine - record and/or display data from the ECU. I bought, and have only used, plain Solo because the whole point of the unit is portability and clearly I won't be plugging a Solo DL into someone's OBD-2 port. Also, none of my cars are new enough to interface with Solo DL.