Trex350

Appreciate if anyone could shed some light on the following.
1.Why did Subaru abandon the coil pack design for the later version WRX ?
2.What are the alternatives available to improve on the coil pack design instead of changing coil packs when they break down ?
3.Do they break down because of the normal life span of the unit or is there an inherent design flaw due to its location in the boxer engine ?

MorayMackenzie

The plug-coilpack system is potentially better in some ways... there are no losses associated with plugleads... the coils only have to fire once a cycle for each cylinder, so they have longer to recover/charge... emi is reduced a bit... and so on. Prodrive use plug mounted coilpacks on the WRC cars and, IIRC, the "new-age impreza" engine may well have returned to a plug mounted coilpack system.

On the other hand... Coilpacks are know to degrade over time and so are likely to need replacment at some time during the cars life... they are, IIRC, about £50 a unit, so it's around £200 for the set.

Moray

Trex350

Thanks for the info. Some tuners claim that if you run higher boost the spark produce by the coil pack may not be strong enough. Is this true ? Maybe they mean really high boost. Or is it a marketing hype to sell some sophisticated ignition system.

Cheers.