Dyno Tuning Melbourne – Sparkplug Tips

Sparkplugs are a big part of a tuneup in a car.  Back in the early seventies, you used to replace sparkplugs every 10,000 kilometres.  Late model engines now, you’ve gone to 20,000 to 25,000 kilometres.

Sparkplug materials have improved.  Engine efficiency has improved.  Now, sparkplugs can last a lot longer.

One thing to watch out for when removing the sparkplugs, and having a look at them.  Watch out for a warn or rounded electrode.  It shows that the sparkplug has done a lot of miles.  The color of the sparkplug might be quite good, and the porcelain may look to be in good condition.

But, if the end of the electrode is rounded, it effectively opens up the gap between the electrode and the earth strap.  The greater gap requires more spark energy to jump the gap.  This can eventually result in engine misfires because the spark cannot jump the larger gap.

What a lot of people tend to do with sparkplugs as well, is, if they are modifying their vehicle, they want to go colder sparkplugs because they’re putting a turbo charger in it, or they just feel that going to colder sparkplugs is a better option.

In some cases this is true.  You don’t want to go too cold, because then, you will have an inefficient burn for the fuel.  When you have an inefficient burn on the fuel, you will have incorrect running at idle, incorrect idle properties, and other similar issues.

Another thing to look for with sparkplugs, (we’ve done heat range), is what type of sparkplug.  Do you want to use copper core, resisted, platinum or iridium.  What type of sparkplug is required for my engine?

The general rule of thumb, is to find out what the manufacturer of the engine has specified.  Failing that, most auto outlets will advise you on what you can use, and what you can’t use.

One big thing to keep note of though.  In a late model engine that is running EFI (

electronic fuel injection

), resisted sparkplugs are a big thing.  You must use them, because the amount of electrical noise that can be generated when you don’t have resisted sparkplugs, may create problems with your electrical system.

For more information, you can contact Robbie McQueen at:

Advanced Engine Management / Wolf Motorsport
22 Melrich RoadBayswater, Melbourne
3153, Victoria, Australia
Ph: (03) 9761 3161

More and more people are running engines that demand more and more from their ignition system.

Most standard ignition systems are of the inductive type.  These ignition systems can generally handle up to 15PSI of boost pressure, sometimes a little more, sometimes a little less.  Gapping plugs down is not the best answer by any stretch of the imagination.  Reduced plug gap can lead to a rough idle and increased fuel consumption.

The next step above inductive ignition systems is Capacitor Discharge Ignition (CDI).

Within the CDI range, there are also different levels of CDI units available.  Some are made for road, some for race, and others are drag racing only.  It is important to use the most appropriate ignition system for your application.  So, if you are not sure, ask someone how knows.

Now, CDI systems do tend to emit a lot of radio frequency noise.  To reduce this noise (that can affect other electronic devices on the vehicle), you must use twisted pairs of wire for both the main power and ground wires, as well as the pairs of wires going to each ignition coil.  One step beyond twisted pairs is to use twisted shielded wire.

The ultimate version of twisted shielded wire is Tefzel (aircraft grade wire). When we build a custom loom for a customer we often use Tefzel wire when the customer wants the very best.  It doesn’t cost the earth, and the result is an outstanding loom.

That’s it for now.
PS: As you’ve just read, CDI ignition systems are at the top end of the ignition system tree.  If you think your ignition system might not be quite up to the task, drop us a line, as we may be able to point you in the right direction and offer some advice on wolfemail@wolfems.com.au.