Delphi vs Eldors

Bnks334

Sergeant
Dec 1, 2016
481
New York
N54 and n55 coils use the same dwell effectively as the coils are basically identical other than manufacturers, which change based on deals and bidding wars generally. You can't just copy and paste the dwell tables simply because n54 uses rpm vs voltage with a temperature scaler (not in most xdf's) while n55 indexes load as well. Ultimately the dwell to saturate the coils will be the same.
Thanks for confirming. The delphi coils that came on n54s are the same part used on n55s so how some of these rumors get started is beyond me. People were also saying the eldor cant be used on the n55 because they dont reach the spark plug. If that were true then why would every other coil be interchangeable lol.

I think there was a tangible benefit to the eldors over the bosch since the elders came with the metal heat shield. But then the Delphi coils also have the heat shield so in that comparison it's moot.
 

V8bait

Sergeant
Nov 2, 2016
432
Texas
Thanks for confirming. The delphi coils that came on n54s are the same part used on n55s so how some of these rumors get started is beyond me. People were also saying the eldor cant be used on the n55 because they dont reach the spark plug. If that were true then why would every other coil be interchangeable lol.

I think there was a tangible benefit to the eldors over the bosch since the elders came with the metal heat shield. But then the Delphi coils also have the heat shield so in that comparison it's moot.
I mean different manufacturers may have better reliability or better QC processes, maybe there's even been silent revisions, but nothing significant on a spec level at least. It's akin to injectors in a sense (although I feel this is a stretch), an index 12 may be more reliable but ultimately uses the same overall tuning and has the same limits etc. Not the best analogy since you code injectors but still parts are nearly the same. Of course a new part will generally work better than a tired old one, especially when they are failure prone.
 

Bmwfixerguy1

Lieutenant
Jun 5, 2017
861
I tested a handful of used OEM style coils including cheap part store ones, and also tested like new Bosch and delphi, they all performed almost identical although the branded ones seemed to last slightly longer, like maybe a minute, some of the used ones without branding only lasted 20 to 30 seconds when stressed. Is that because they were old or just cheap I dunno. I really doubt eldor will test any different.



Lots of issues with this write up... specifically the "part 2" at least haven't read part 1. For one he is quoting injector mosfet specs and circling injector mosfets on the board, and talking about ignition igbt. He is worried about flyback voltage for the injectors (because that is what kills their mosfets) but he's monitoring the ignition system... that system needs the back voltage to push the primary energy over 300v, so it can get to 30kV+... he even says that happens but states it's too much, which is wrong, it's absolutely needed for the ignition (but not injection). It's why there's a 500V capacitor parallel with all the ignition coil voltage leads already. It's like he confuses or doesn't realize they are isolated systems. I think he's a smart guy but he needs to go over things again imo.
Not that I'm questioning your answer I'm more questioning the internals to understand.. I have always found when a bank of mofets gives up the ghost there will always be one completely dead coil in that bank... What is the correlation.. basically who is the chicken and who is the egg... I could never understand why two different systems had that affect
 

V8bait

Sergeant
Nov 2, 2016
432
Texas
Not that I'm questioning your answer I'm more questioning the internals to understand.. I have always found when a bank of mofets gives up the ghost there will always be one completely dead coil in that bank... What is the correlation.. basically who is the chicken and who is the egg... I could never understand why two different systems had that affect
I don't know why that would be the case to be honest. When my mosfet went out it was just that, dead mosfet. Coils were all fine. Happened when I was low on gas, like really low 2 miles to empty or something, made a little pull before the gas station, misfired, done. Testing the upgraded coils on a car a few years ago it developed a misfire, and after 2-3 code clears had the internal failure code. Replaced the mosfet but no coil issues (although that was with PR coils). It seems kinda mixed in that sometimes there's a failed injector of coil sometimes not, so I can't really say with any certainty. My theory is misfires cause flyback voltage through the injector (it has a little coil internally too) and that is what frys the things, and sometimes frys the injector. Not sure why a coil would die from that, so maybe the coil failure is just a common cause of misfire?

Not sure how much it really matters anymore, only 1 year was affected and the fix is pretty easy, upgrade the mosfets or upgrade to MSD81. Curious issue though.
 

Bmwfixerguy1

Lieutenant
Jun 5, 2017
861
I don't know why that would be the case to be honest. When my mosfet went out it was just that, dead mosfet. Coils were all fine. Happened when I was low on gas, like really low 2 miles to empty or something, made a little pull before the gas station, misfired, done. Testing the upgraded coils on a car a few years ago it developed a misfire, and after 2-3 code clears had the internal failure code. Replaced the mosfet but no coil issues (although that was with PR coils). It seems kinda mixed in that sometimes there's a failed injector of coil sometimes not, so I can't really say with any certainty. My theory is misfires cause flyback voltage through the injector (it has a little coil internally too) and that is what frys the things, and sometimes frys the injector. Not sure why a coil would die from that, so maybe the coil failure is just a common cause of misfire?

Not sure how much it really matters anymore, only 1 year was affected and the fix is pretty easy, upgrade the mosfets or upgrade to MSD81. Curious issue though.
Yea I can't say every one does it but I have had about 4 personally and have read quite a few online as well.
It's fallen into the who cares just fix it part of my brain by now but has always been a curious case none the less šŸ˜
 

syn909

New Member
Jun 27, 2018
9
Had a mis-fire pretty early on with my stock delphis after the car was tuned, replaced with eldors and after 25k+ miles stage2/hybrid turbo still no ignition issues. Have had a set of PR coils in a box for a long time just waiting for the eldors to give out.
Hows your battery health?
 

Noxide

New Member
Jan 8, 2020
2
MSD80 with Delphi Coils, 29psi and port meth. Blew MOSFET 2, replaced with FDB14N30TM and been great ever since. Delphi coil didn't fail with the MOSFET and still lives on to this day.
 
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