Make your own engine earthing kit
Dead easy to do for anyone and does have marked and proven benefits for your MX and almost every make of car.
If you notice with your MX there is just a single solitary cable from the negative ( - ) on your battery that connects straight to your bodywork that acts as the whole ground circuit for your car. The cable is rated to 50 amps but that single cable has to complete the circuit for ALL electrical devices running on your car, lights, sound system engine management and all engine ancillaries.
Like lightning electricity will always take the shortest route to make the better circuit but on the mazda MX3 they have not really taken the shortest route.
Different metals also give different resistances, copper, aluminium and gold have the lowest electrical resistance so its easy for the electrons to pass along them where as Iron and types of steel electrons find it harder to travel through. The engine bay has a real mixture of metals and then gaskets separating them also stop the electrons so they have to pass through the bolts into the next section causing them to earth through these bolts like lightning hitting the top of churches etc it directs the flow around the engine bay.
Adding a few extra 50 amp cables to the engine directly cuts the corners that electrons have to take and gives a much better path for the electricity to make its circuit.
On hugely modified engines its proven to….
improve fuel efficiency
quicker engine starts
reduced audio noise
better protection from potential engine damage from poor ECU outputs
With the mazda MX3 it may not notice very much but its something that you have done that may help your car as its starting to get a bit older now.
The mazda MX-3 has 2 grounding points fitted as standard on the engine, from the engine mount on the left side that connects to the bodywork and then from the gearbox (under the air filter case) to the bodywork.
I have made 3 cables from 50 amp black earth cable, total 3m purchased for around £4 plus 6 yellow ring connectors cost £1 as pictured below.
There are 2 main areas on the engine for electricity
STARTING + IGNITION
I looked around the engine bay to make these 2 areas easy to earth with the shortest direct route for a complete circuit.
I cut the cables to the correct length with a small amount of excess length for securing and to move as the engine moves around while driving
To sort the starting side I connected a 50 amp length of cable to the same bolt that is used to ground the starter motor to the gearbox.
This is highlighted with the green arrow in the center of the 3 arrows
Next to give the shortest route for the spark plugs to earth back to the battery I chose a bolt on the inlet manifold that holds a small mount on the rear to help the rear 3 plugs with a direct route
This is highlighted with the top arrow
To give a direct route for the front 3 plugs I did have a smaller ring terminal that I mounted onto the small bolt that holds the distributer on but when buying a pack of terminals they dont mix sizes so it will connect perfectly to the right hand center bolt for the rocker cover.
Highlighted with the bottom green arrow.
Then simply connect the 3 ends directly to the battery negative terminal with the retaining bolt and its done.
I have found since fitting this…
The engine fires and starts quicker in the mornings and throughout the day.
Havent gone far enough yet to notice any difference on fuel
The interior light seems a little brighter when running
Have lost a bit of the flat spot at lower end of revs.
ALWAYS REMEMBER TO CHECK THAT YOU ARE CONNECTING IT CORRECTLY TO THE BATTERY
IF CONNECTED THE INCORRECT WAY THIS WILL CAUSE SERIOUS DAMAGE TO YOUR CAR.
IF YOU ARE UNSURE DONT BE AFRAID TO ASK SOMEONE OR JUST DO NOT RISK IT !!!
I MYSELF OR THE UK-MX3 WEBSITE CANNOT BE HELD RESPONSIBLE FOR DAMAGE CAUSED TO YOUR CAR BY INCORRECT FITMENT