I’ve been developing this conversion in my head for a number of years because I always thought that, eventually, our OEM coils would no longer be made and I wanted a back-up plan for my car. In the last four or five months, I noticed that I was getting some missing/bucking under WOT, and high boost, at high speed. I figured coil (or POS) but I didn’t want to spend the money on replacing old (but perhaps robust) technology when newer technology is out there.
I know all about the 1.8t coil pack recall on some of the Bremi-made coil packs but I think that VW/Audi is through all that now. For whatever reason (excess supply, the need to do some good PR), these coil packs are now very reasonably priced. Since I had the need and the price was right (about $200 – $250 for the parts versus the OEM equivalent of about $900 for five coils, two OEM POS units and five spark plug connectors), I decided to make the conversion.
This conversion is intended as an alternative to the original equipment (OE) ignition system that uses two 3-channel power output stages (POSs) and five individual coils each with a replaceable sparkplug connector. The 1.8 t coil pack conversion described in the pdf on S-cars.org works but there are no guarantees about improved performance or freedom from failures. The 1.8t coil packs have built-in POS units as well as coils and plug connectors. At the time of writing this, these 06B 905 115L coil packs were about $30 each. In comparison, the OE POSs were about $150 each (and you need two) and the OE coils were about $115 each (and you need five). So even if the odd 115L coil pack fails every once and awhile, they are far less expensive than the original ignition system.
Conversion story and PDF contributed by Dave Forgie