Does a sports coil increase performance?

[waynne]

Just wondering if there was any point to adding a sports coil? Does it give more power? Will upgrading the HT leads also help with power cos Im looking at some leads with a resistor that is meant to give a stronger spark when voltage increases.

[HDi fun]

You can never have too much spark - resistive leads are pretty much standard nowadays so don't pay too much.

You should also consider high performance plugs that can take the extra wellie without needing to be replaced constantly. Be certain that the plugs have the same reach as the standard ones otherwise your likely to have valves or piston crowns smashing into them.

Plug heat rating is another factor, this is determined by the profile of the insulator on the anode. If you tune your car in other ways you may need a colder plug to prevent over heating. If you do short journeys then hotter plugs help as they literally get hotter, faster thereby shifting the carbon deposits that cold running causes.

[waynne]

Cheers m8y that helps a lot. What does to much heat rating do then? Is to low heat rating also bad?

[HDi fun]

You have to match heat rating to the car. If the plugs overheat then fit a cooler one. If they foul up (assuming that engine tune etc is correct) then a hotter one will allow the deposits to be burned off sooner.

An overheated spark plug can cause major problems - misfires and pre-ignition (pinking) and can destroy an engine. They look kind of glazed and white if this is happening.

Tuned engines are always an unknown quantity so you might have to experiment a bit.

Some of the Japanese NGK and Nippon Denso plugs are superb with three platinum tipped electrodes. These really belong in race cars at about twenty quid each but they will take ANYTHING you throw at them.

If you can, go for a coil per plug setup, these are pricey but you'll get stunningly even fuel burning, which means better economy and LOADS MORE TORQUE AND POWER!!!!

[waynne]

You're Torque mad my friend!

[HDi fun]

I am indeed, let's face it we all talk power but what we all drive is torque.

Power is only a function of torque and revs