A new dash

Posted on October 14th, 2014 in Economy,testing,tools by Julian Edgar

I’ve always enjoyed having lots of gauges in a modified car. Even in my first car – an air-cooled, 2 cylinder Honda Z – I fitted an oil temperature gauge. Subsequent cars have had gauges that show everything from exhaust gas temperature through to air filter restriction.

So it’s not surprising that I have been enjoying the MoTeC CDL3 digital dash that I have fitted to my Honda Insight.

What has surprised me, though, is how much my enjoyment of the car revolves around the dash. These days, where driving fast means that you get locked up, having the ability to be entertained by the dash rather than by just the driving is a major advantage. And being able to program the dash to show the parameters you want adds another layer of enjoyment.

So I have the dash displaying on the main screen:

– Engine rpm (bar graph)
– Speed (derived from the dash’s GPS input)
– Gear (worked out by the dash based on road speed and revs)
– Fuel level (using the standard Honda fuel tank sensor, with the result calibrated in per cent)
– Engine temp
– Lambda number (showing mixture strength, where Lambda 1 = 14.7:1 AFR)

Then, on the bottom line of the screen and able to be scrolled through by pressing the standard Honda FCD button on the dash, I can further bring up:

– Manifold pressure
– Inlet air temp
– Fuel injector duty cycle
– Engine oil pressure
– Engine oil temperature
– Ignition advance
– EGR valve duty cycle
– Water/air intercooler pump duty cycle
– VTEC on/off
– Lambda short term trim
– Lambda long term trim

The dash is also able to be configured to display different text-based warnings. I currently have warnings displayed for:

– Seatbelt
– Door open
– Engine hot
– Engine cold
– Oil pressure
– Lean
– Battery level
– Inlet air temp
– Fuel level
– Change up
– Change down
– ECU hot
– Dash hot

These warnings are all ‘smart’ – eg the seatbelt warning shows only when the car exceeds 5 km/h with the seatbelt off, and the ‘change up’ warning shows only when a certain combination of throttle position, gear, manifold pressure and road speed occurs.

The CDL3 dash is now part of the old range of MoTeC dashes that use a B&W LCD (rather than the newer models’ colour displays) and cannot be configured with anywhere near the versatility of the current stuff. However, the major advantage from my perspective is that the old dash shape fits perfectly into the Honda’s instrument binnacle.

So what can’t the CDL3 do, things that I’d really like? The answer is not what I would have thought before buying it: more than anything else, I’d like the dash to be able to perform maths functions. For example, to be able to show trip fuel economy, where fuel used is divided by distance travelled. And I’d also like it to be able to show maxima and minima of all readings, and….

In fact, the CDL3 has been such a success that I am upgrading to the ADL3 dash – same footprint and display, but the ability to do maths functions… and a whole lot else. Luckily, like the original CDL3 dash, I have found one second-hand – as I write, it’s on its way.

2 Responses to 'A new dash'

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  1. Julian Edgar said,

    on October 25th, 2014 at 7:17 pm

    Been working all day programming the ADL3 dash.

    The dash has three different modes, dubbed ‘race’, ‘practice’ and ‘warm-up’.

    I have made the ‘warm-up’ display show any time coolant temp is less than 80 degrees C.

    It displays:

    – engine revs
    – coolant temp
    – air/fuel ratio
    – engine oil temp
    – GPS speed
    – fuel level (because in the other dash modes I don’t show fuel level, just a warning when it is low – so this way I get to see it each time the car is started).

    At 80 degree C coolant temp, the dash auto swaps to the main display. This shows a huge range of parameters – I won’t list them all here.

    I also have a driver-selectable display suitable for driving for best fuel economy. The main bar graph (normally for engine rpm) then changes to instantaneous fuel economy (calculated from GPS speed and injector pulse width), and the dash in this mode also shows GPS speed, manifold pressure, air/fuel ratio (etc). It also brings up trip fuel economy and average air/fuel ratio (ie an ongoing running average of this parameter).

    I also have a special text that displays only in this ‘fuel economy’ mode – ‘Poor Fuel Eco’ that shows when instantaneous fuel economy is more than 3.5 litres/100 for more than 4 seconds AND gear is less than 5 AND equal to or greater than 1 AND throttle position is less than than 50 per cent.

    I might also add that today I tried more than a few things that didn’t work….. it’s easy to recount it afterwards when it all works!

    Another 4-5 hours*, but lots of fun.

    * I know that up above I said it was a full day… it wasn’t, but it felt like it!

  2. Julian Edgar said,

    on October 27th, 2014 at 6:42 am

    Starting to get the hang of the maths functions in the ADL3 dash / controller.

    The basics are: plus, minus, multiply and divide. Then you have greater than, less than, greater than and equals, less than and equals, equals and not equals. You also have ‘and’ and ‘or’ logic functions.

    I am currently calculating instantaneous fuel consumption by:

    (‘Fuel Inj Duty'[ratio]*0.643*60)/(‘GPS Speed'[km/h])*100

    So the fuel injector duty cycle (per cent opening time of injector) is multiplied by flow in litres per minute (3 injectors @ 214cc/min = 0.643 litres/minute), and then by 60 to get litres per hour. This is divided by speed in km/h to get litres per kilometre. This is then multiplied by 100 to get litres/100km.

    That works really well, except when you are stationary where the figure becomes infinite! That in turn isn’t so good if you’re trying to additionally calculate averages, so I am today trialling an additional expression that means the calculation for instantaneous fuel economy works only at speeds above 0.5 km/h.

    In addition to these simple expressions, you are have a range of functions: tan, cos, log and so on. Unfortunately, in this list there are not derivatives, integrations, smoothing or filtering – all of which are available in the maths functions in the i2 pro data analysis software from MoTeC. I was very much intending to use derivatives and integration, so that’s a bugger.