[Mayuri Krab]

This doesn't make me very confident in the so called 'german engineering' of bmw parts.

My 22 year old skyline is still running on original coils from Nissan with no issues (and I floor it all the time) and that was up boosted for the 8 years I owned it

EDIT: I changed my coils and plugs when I got my mods done on the bmw just to be safe as well.

[335iNavyGuy]

Originally Posted by ferocity02

How does a tune affect the coils? As far as I know, the tuNE can just change ignition timing which shouldn't be any harder or easier on the coils, it just changes when they fire. Or can the tune change the duration or intensity of the fire?

Makes them run harder and faster, causing old ones to die. Its not a direct cause but i promise you if you have a higher mileage 335i and add a jb4 you will lose some coil packs.

[torn08]

Mhd e85 back end and map 7 did me in yesterday. New delphi could arrived today, Thank you Amazon!

55K miles

[ferocity02]

Originally Posted by 335iNavyGuy

Makes them run harder and faster, causing old ones to die.

How does the tune make them run harder and faster? As far as I know the tune can't adjust any of those things directly, unless it's doing it indirectly. I'm not doubting you, I'm seriously interested

[optigrab]

Originally Posted by ferocity02

How does the tune make them run harder and faster? As far as I know the tune can't adjust any of those things directly, unless it's doing it indirectly. I'm not doubting you, I'm seriously interested

Its so common cobb actually made a video about it.

i would imagine like most components they wear and become less efficient as they get older

[335iNavyGuy]

Originally Posted by ferocity02

How does the tune make them run harder and faster? As far as I know the tune can't adjust any of those things directly, unless it's doing it indirectly. I'm not doubting you, I'm seriously interested

I dont know the specifics lol, guessing faster revs due to higher boost will induce higher voltage or faster relays of voltage that the coils arent used too making them overheat and die. But it only happens to older ones or worn ones. Wont happen to new ones too often .

[optigrab]

Here is a link to 7 pages of info about coils for anyone who is interested is it a good read.

http://www.autoserviceprofessional.c...to-know?Page=1

Highlights

The largest firing voltages happen typically in snap throttle acceleration conditions. The change in engine speed, the change in fuel ratio, and the load on the engine contribute to the higher required voltage

Coil failures can also be the result of shorted windings in either the primary coil or the secondary coil. If the coil driver fails, it may not be able to limit the coil primary current to safe levels.

The primary is not designed to handle anything like 28 amps. The heat which that amount of current will cause will surely melt and destroy the primary coil if it is allowed to happen.

Other possible failure modes include mechanical damage to the coil itself or the electrical connections to the vehicle wire harness. Coils with obvious mechanical damage such as broken or cracked connectors or high voltage towers should be replaced.

There is no wear-out factor in the coil itself other than thermal cycling and the damage it may cause. Boots and wires do age, resulting in reduced insulation value over time.