tuneda4

i have an 04 and a ton of people say that they are not the way to go. you really noticed that big of a difference?

MikTip

it was a noticable difference in the engines performance. However the engine did run smoother, just not a lively as with the R's. So I re-installed the R's and lively engine was back! :O)

This is with GIAC K04, Genesis injectors, and OEM NGK plugs.

I was thinking about trying the Hitachi's with a set of Bosck FRD plugs....

MikTip

it maybe a long time before one of the Hitachi's goes south on you! ;O)

Mrkrad

i mean they are both $24.99 at clairs (audi super store dot com) and alot easier to get due to shortage of "R" packs.

but if others claim you can run more gap then the hitachi's must output more power and your car would feel more spritely on their own.

something doesn't jive. maybe they respond differently to the dwell time the tuners use.

MikTip

From 2002-2005, we all have different mods on our engines, different ECU software, injectors, plugs, etc, etc....

Maybe data-logging engine data, with the various modded engine configurations?

But who would this serve, and is it really needed?

Who here, could provide such a test, and have reliable/repeatable data useful for everyone?

The biggest mystery is why the coils fail in the first place! Heat? Voltage? Material failure? Other?

The Hitachi's arose as a suitable replacement, in the name of longevity sake.

To date, I've never heard of them as being a "performance" replacement! ;O)<ul><li><a href="http://www.mylemon.com/VW_18T.html">http://www.mylemon.com/VW_18T.html</a</li></ul>

diagnosticator1

The Hitachi coilpacks, and the stock Bremi "X" revision coilpacks "look" about the same to the ECU. The method the ECU uses to operate the coilpacks, is by using a transistor switch inside the ECU, that connects the coilpack primary circuit to ground, completing a path for current to flow thought the coil primary circuit. At the exact moment, referenced to crankshaft/piston position, that the ignition spark is required to occur, the ECU transistor switch "switches state" (IE, the transistor state changes from ON to OFF,) disconnecting the primary circuit connection from ground, resulting in the collapse of the magnetic field in the primary coil winding, and from magnetic induction, a high voltage is induced in the secondary coil circuit, creating the spark at the plug.
In consideration of the above, the ECU is not effected by the variation in the coilpack electrical properties/specs directly.
IHTMS :&gt;/

diagnosticator1

For sure!

diagnosticator1

Being the only possible reason for the differece you experienced. Possible if the Hitachi coils present a different current load on the ecu output transistors, compared to the Bremi coils, and maybe a resulting variation in ignition "dwell" time. I don't know how/if the separate log runs could be arranged so that other variables could be disregarded in the results.

MC Hammered

But aren't yours a different variant than the coilpacks being sold now?

diagnosticator1

I am convinced the cause of the failures of the stock coilpacks, is provoked by chipping, and the higher secondary voltages that accompany the higher cylinder gas pressures existing at the ignition point, eventually breaks down the insulation inside the coilpack, that then allows the high voltage discharge to jump/short inside the coilpack.
This also occurs with stock unchipped cars, and demonstrates the susceptibility of the stock coilpack design to fail, caused by weakness of the insulation design and or materials.