2021+ Aprilia Tuono V4 and Data Challenges

I was recently at Sonoma Raceway (2023-09-11, Fun Track Dayz) with my Tuono V4 and my Ninja 400. I wanted to capture data on both bikes and it was a great day with only ~75 customers so the groups were not too full. Unfortunately one of my AiM Solo 2 DL units (I have 2) is in for service with AiM West Coast so I loaded the configuration for the Aprilia E5 and the custom Ninja 400 config and planned to switch between bikes and toggle the configuration.

Since I was only a couple of seconds off the time on my Daytona, I wanted to compare the best laps on the Tuono to the Daytona. Upon getting home and downloading data, I noticed that lap times on both bikes (Tuono & N400) seemed about right but when I wanted to compare a lap from my Daytona (using the EVO4s logger with an external antenna) and the Tuono (S2DL), I saw some curious speeds and fluctuations in the speed traces between the two, not to mention some slow points that seemed way off.

Red is the Daytona from last year, Blue is the Tuono, ~2-second difference but slow points and speeds are pretty wonky on the Tuono.

This data looked like two completely different riders. I then decided to pull up the Ninja 400, which was a good 8-9 seconds off the Tuono from the same day and traffic definitely impacted my pace so there are some spots where I just wasn’t able to execute as I wanted but check the slow points (400 in green).

Same as above, Ninja 400 in green
Big giveaway – check the GPS Positional Accuracy. The Red is the Daytona with an EVO4s and GPS09 external antenna, Green and Blue are the same S2DL but the Green is on the Ninja 400 with a super simple electrical system that probably isn’t generating any EMF.

So clearly something was not correct with the Tuono data. I had to do some sleuthing to try to figure out what was going on. For those who are interested, I’ll embed the discovery video below. I added a display page to all of my S2DL configs that includes satellite data, namely positional accuracy and number of satellites obtained. I mounted the S2DL to the Tuono, rolled it into the driveway for a so-so view of the sky, and powered it on by itself. Fairly quickly it picked up enough satellites to register GPS GOOD. Then I powered on the bike. As soon as I did the positional accuracy increased quickly and the number of satellites obtained dropped. I checked in with AiM about this and they have seen it. As I see it there are two possible options:

1.) Use an external antenna, but that’s not presently an option with the S2DL so I’d have to add a data logger (EVO4s or EVO5) and I really don’t want to go to that much effort for a street bike that sees a few track days.
2.) Try to shield the EMF radiating parts of the Tuono to reduce the interference with satellite reception of the S2DL

That said, I’m going with the 2nd option. I’ve ordered the Bonamici aluminum protection case for the dash (which is likely the source of the EMF). I may also look into a clear EMF-blocking layer I can put over the screen of the dash if the enclosure isn’t enough.

Bonamici Racing Dash Case/Enclosure
Video demonstration of the RF interference between the Tuono V4 (Euro 5, 2021+) and the Solo 2 DL

I’ll recreate the test once I receive and install the dash enclosure. Hoping to have it before the Tuono’s next track outing. I’ll update this post once I’ve installed and tested it.