Picking gauges

Posted on April 2nd, 2014 in Economy,Honda,Hybrid Power,testing by Julian Edgar

It’s not often that you get a clean slate in terms of designing an instrument panel.

With my Honda Insight project, where the standard instrument panel is being ditched and replaced with (primarily) a MoTeC CDL3 digital dash, to some extent the type of display becomes obvious – it’ll be dominated by the MoTeC unit.

But what about the factory-fitted warning lights – things like ABS, EPS (electric power steering) and airbag malfunction indicators? And how will high beam, low beam and the action of the indicators be shown? And will there be data that I will want to be able to see but the MoTeC dash won’t easily show?

Despite the dash not likely to be installed for many months, I’ve been mulling over these ideas.

At this stage – and things may well change – this is what I am thinking I’ll need:

Warning lights for:

 – high beam

 – low beam

 – left indicator

 – right indicator

 – EPS

 – ABS

 – airbag

 – handbrake / braking system fail


Small backlit numerical LCDs for:

 – high voltage battery voltage

 – electric motor current flow


MoTeC dash display of:

 – engine rpm

 – coolant temp

 – fuel level

 – road speed

 – manifold pressure

 – intake air temp

 – gear

 – oil pressure

 – oil temperature

 – turbo exhaust back-pressure

 – water/air intercooler pump drive voltage

 – 12V battery voltage

Some of these MoTeC-displayed parameters (eg intake air temp and rpm) will be communicated via the CAN bus from the M400 ECU.

One parameter (selected gear) will be internally calculated in the dash, while other parameters (like oil temp and pressure) will require dedicated sensors.

Note that the MoTec dash allows different data to be displayed depending on the mode selected – so not all of these things will be available all at once!

On the list above there are a couple of unusual ones.

I want to be able to see turbo exhaust back-pressure because, in order to provide low rpm torque, the turbo that is being used is small. However, if as a result of its small size, the exhaust back-pressure is overly high, then fuel economy will suffer. It’ll be good to be able to see this figure.

So why show the water/air intercooler pump drive voltage? The pump will be varied in speed by the ECU. This is needed because I want to control the intake air temp, rather than just keep it as low as possible. For much of the time, I would expect that the pump will be operating at less than full speed. Displaying pump drive voltage will allow me to see at what speed the pump is being driven. Not only will this be interesting in itself, it will also allow me to assess how effective the control strategies are that are being used to operate the pump.

As I said, all still a long way off, but I need to start sourcing bits and installing sensors right now.