In the June 2016 issue of Racecar Engineering magazine (V26N6, "False economy"), author Danny Nowlan makes a strong case for easing the restrictions on data logging in Formula 4 cars.
"Formula 4 has been created as the new nursery for drivers and engineers and mechanics," he writes. "If they are not data literate, they don't stand a chance." He goes on to show that a data system sufficient to create 3D track models as well as chassis simulations in ChassisSim could cost less than a few days of track testing. He proves his point with two example systems: MoTec ADL3 and Magnetti Marelli DDU 310.
But the following statement at the end of the article grabbed our attention: "These are the Rolls Royce options," he admits, "and there are other systems, like AiM, that can get you going for a lower price."
Just how much lower, we wondered?
The systems laid out in the article were specifically set up to log engine RPM, one engine temperature, oil pressure, steering angle, throttle position, brake pressure, g-force in 3 planes, suspension travel on all 4 corners, and GPS data. So let's build a similar AiM system and compare apples to apples.
The ADL3 and DDU 310 are both data logging dashes. The ADL3 has an LCD display, but the DDU 310 has a full-color TFT display. The current AiM dashes that are most directly comparable are the AiM MXL 2 Data Logging Backlit LCD Dash (similar to the ADL3) and the AiM MXS 1.2 Data Logging Full-Color TFT Dash (similar to the DDU 310).
|AiM MXL 2||AiM MXS 1.2|
With the two "Rolls Royce" options, you will have to add a 3-axis accelerometer and GPS -- both of which are already standard on the MXL 2 and MXS. The article also lists sensors for temperature and oil pressure, but FIA regulations for F4 require that those two channels must be available as part of the CAN data stream from the ECU. Both AiM dashes can receive these channels via the CAN stream, so we can eliminate them from our price list. If the engine uses fly-by-wire throttle, then FIA rules also allow throttle position to also be included in the CAN stream. But let's include the TPS sensor in our list anyway, since the full details of the US F4 engine package haven't been published as of this writing.* We will also need to add the optional Auxiliary Harness to the MXL 2 or MXS in order to access channels 5 through 8 for the shock pots.
* It has been tentatively announced that the Honda-powered US F4 will use an FIA-homologated Life F88 ECU similar to those used with the Ford and Renault F4 engines in other countries. The Life F88 will communicate with AiM systems, and so will the Magnetti Marelli ECU used with Abarth F4 engines. So, all current FIA-spec F4 engine/ECU combinations are able to send engine temperature and oil pressure data directly to an AiM logger.
Let's build the systems
|Data Package Comparison|
|Item||MoTec ADL3*||AiM MXL 2||Magnetti Marelli DDU 310*||AiM MXS 1.2|
|3-axis g sensor||$890||Included||$293||Included|
|Temp sensor||$148||CAN Data Stream||$48||CAN Data Stream|
|Oil pressure||$296||CAN Data Stream||$137||CAN Data Stream|
|Steering angle sensor||$148||$142||$167||$142|
|Brake pressure sensor||$296||$160||$146||$160|
|Auxiliary sensor harness||n/a||$350||n/a||$350|
|Suspension travel sensors**||$296||$1120***||$334||$1120***|
* Prices were converted to USD on 6/30/2016 from AUD quoted in the article.
** The article did not make it clear if the price quoted was for all 4 sensors or just one. We will assume that the price covers all 4 sensors to give them the benefit of the doubt.
*** This is the cost for 4 of the most expensive shock travel sensors (a "worst-case" scenario).
What have we learned?
As the table shows, the AiM MXS system as specified in the article is nearly $1850 less expensive than the comparable Magnetti Marelli, and the MXL 2 is over $2300 less than the MoTec option. The cost of the software is also worth considering: AiM provides the full version of Race Studio 3 software free of charge. MoTec includes the "Lite" version of their analysis software with the dash, but the "Pro" version is only available at additional cost. Magnetti Marelli does not include any software; they charge a license fee instead.
Not only that, but both AiM dashes have built-in capabilities that make them immediately useful right out of the box. If your budget doesn't allow a $4000 investment right now, roughly half that much will get you a fully-functional data logging dash that will allow you to monitor all aspects of engine health and analyze the driver's racing lines. AiM systems also allow you to add sensors later, so you can expand and customize the already powerful and versatile system on your own schedule.
But wait, there's more
The 2016 FIA F4 regulations impose a cost cap for a complete data system at €5000 ($5540 USD as of June 30, 2016). The AiM MXL 2 and MXS 1.2 dashes can provide all of the instrumentation and data logging capabilities advocated in Mr. Nowlan's article while still coming in well under the current budget cap, but his example systems would not. The AiM systems even have enough left over to add an AiM SmartyCam HD GP Rev 2.2 Video Camera without exceeding the cost limit.