VI Monitor Frequently Asked Questions

This is your first point of call for answering VI queries. Below are all of the most frequently asked questions about the VI Monitor.

Where does the VI gets it's power from?

VI takes its power directly from the OBD-II, so there is no need to plug in a cable to the cigarette lighter socket. Having just one cable (OBD-II) for all of it's needs reduces clutter in the vehicle.

Does VI support external gauge sensors?

At this point VI only supports data input coming directly from the ECU and not external sensors.

I have replaced my engine ECU. Will VI still work?

Aftermarket ECU replacements sure as a Power FC do not confirm to OBD protocols and therefore VI cannot understand and translate the data being received. At most you will only get a power feed which will enable you to use the ‘G’ based functions only.

Is my car compatible with VI?

Due to each vehicle manufacturer complying with ODB standards at different times for different vehicles, it is not possible to give a yes or no answer to this question for every vehicle. We recommend that you contact your vehicle manufacturer.

Can I use VI to tune or remap my ECU?

No. The data that VI uses is read-only. VI cannot effect any changes on your ECU mapping.

How many parameters can I monitor?

The number of parameters available is dependent on the make and model of vehicle. In our testing, available parameters have ranged from as low as 5 up to 18. From the list of available parameters, you can view up to 3 parameters at any one time.

How many parameters can I record at one time?

In Monitor mode, you can only record the parameters being viewed (max of 3) at any one time. However, you are able to cycle through preset Monitor screens while recording. The resulting data log will display all parameters that have been recorded, but will only show active data for the period of time that the parameter was viewed on screen.

I have installed an aftermarket ECU Chip. Will VI still work?

An aftermarket ECU chip might not alter the information being put out by the ECU’s OBD port – only the information it sends to the various components within the engine. So VI should not only continue to work, but the data being displayed will reflect the increase in power resulting from the chip upgrade.

Will it output to an external screen?

VI Monitor does not have any outputs for external video or audio.

Does VI have Sat Nav?

No. VI Monitor does not have a GPS transmitter/receiver.

Does VI have a video input?

No. VI Monitor does not have any input for external video or audio.

How long will VI record for?

It is not possible for the OBD socket to output to more then one device at a time.

How accurate is the performance measurements & dyno?

As VI relies on information from your ECU for many of it’s performance measurements and Dyno readings, it is only as accurate as your ECU. Timing readouts that are not ‘G’ triggered may experience a small discrepancy due to data transfer rate from the ECU. This may mean that there is a difference between timings done at a drag strip and timings done by VI, however timings done by VI will be accurately comparable with each other and are repeatable.

Can I run multiple VI’s?

It is not possible for the OBD socket to output to more then one device at a time.

Can VI replace my OE dash display?

It is possible that (dependant on the vehicle) VI can display enough parameters to replace your OE dash display, however we would not recommend it for everyday vehicles as you are limited to viewing three parameters at any one time.

My Dyno results are not the same as my local Rolling Road:

The reason for the results differing from your local tuning shop are that the VI Monitor works out ‘NET’ horsepower whereas your tuning shop will work out the horsepower at the wheels and will also convert that to horsepower at the flywheel. Net horsepower is how much power your car is generating in real world conditions i.e. the amount of power your vehicle needed to accelerate it to a measured speed at a measured G at any point, and will be effected by factors such as wind resistance, vehicle weight inaccuracies etc. A tuning shop dyno will not take these into account.

My Drag strip results do not match my times at the track.

This is most often caused by ‘rollout’. By this we mean that when you are at a drag strip the time starts when your wheels cross a certain fixed point on the track, this can be after you have already started accelerating so you could be doing maybe 2 or 3 mph or more. The VI Monitor starts timing as soon as the vehicle moves meaning that the times and speeds during the run can differ quite considerably. Pitch factor can also cause some very minor discrepancies but as long as the same conditions are used from run to run you can still compare your times against previous runs to gauge any improvements made.

My Speed readout does not match my vehicle speedo.

It is very common for vehicle speedos to read slightly optimistically and this can be up to 15%. This may be built into the speedo itself and will be the reason that the two values differ. VI Monitor reads the speed value being provided by your vehicle's engine ECU and displays it directly without modification

If you find that the reading is very inaccurate it may be the case that your vehicle has had some type of speedo correction device fitted (this is often the case for imported cars). In some cases this will make the ECU send out a corrected figure which is not the OBD-II standard. In this case please go to the units setting menu (page 34) and select the imported vehicle setting and then select your chosen unit (MPH or KPH).
I can drive my vehicle very slowly and the speed readout on the VI Monitor still displays zero.

This can be caused by the vehicle having some kind of speedo conversion device fitted. This can cause a delay in the signal being sent from the speed sensor to the ECU and is the most likely cause of the VI not displaying very low speeds (normally below 3mph). This is sometimes replicated by the vehicle speedo (drive very slowly and see if the vehicles speedo moves).
My Throttle position and/or Accelerator position is never 0 or 100.

VI Monitor displays the data that is sent to it from your vehicle ECU. This may mean that your vehicle ECU is not showing a fully open or closed throttle. Often this is for idle control etc and to control fueling at higher throttle loads. It is very common for this to never show 100% even though you have the accelerator pushed all the way down.

My ‘G’ readouts in the ‘G’ meter display appears to be back to front.

* Acceleration G is the force exerted on the unit in a rearward direction as you accelerate. Therefore the dot, in the centre of the VI display, moves downward to the bottom of the gauge.
* Braking G Force is the opposite of acceleration force. So the forces on the VI unit are towards the front of the vehicle and the dot on the gauge therefore moves towards the top of the display.
* Left G Force is the force exerted on the unit in the left direction so this will increase when the vehicle turns RIGHT.
* Right G Force is the force exerted in the Right direction and increases when the vehicle turns LEFT.

My RPM Needle movement is not smooth.

This is caused when the data rate that your vehicle’s engine ECU uses is not being quick enough to update smoothly. You can minimise this problem by turning off any unused VI gauges (just having the RPM displayed will provide the quickest response). You can also use the Dial Damping function (page 33 of User Manual) to smooth out the needle movement.