Technical Ignition Coil Secondary Spark Energy Comparison (N54/N55, B58 and PR)

[wheela]

I ll answer the question myself

Judge yourself (@Torgus, u got a "like" as you have been right)

3 years old OEM Eldor with ~50k miles on it:
View attachment 73615

Brand new Dinan with 5 miles on it:
View attachment 73616
PLUS:
View attachment 73617

Of course thats not the scientific way to proof things. But its true street experience...

With the Dinan i got corrections while with OEM Eldor coils i had none. Also i got long crank with the Dinan on 2 out of 5 engine starts (including the shadow code above). The logs have been taken one day apart of each other.

Thanks for sharing, the more information the better!

But I'm skeptical that the coils are the cause here? Can anybody explain how a less energy coil could cause timing corrections? Unless the DME responds to misfire events (failure to ignite mixture) with timing corrections, but I didn't think that to be the case. I suspect the timing corrections and hard starts you saw with the Dinans may have been due to some other factor(s) (bad fuel, different ethonol %, iat, etc.), but that's just my own suspicion. Some days I get corrections, other days I don't - on the same coils.

If anybody knows if/how coils could influence corrections, I'd love to hear about it! I just replaced my stock Delphi's with Eldors (i'm n55), but I didn't expect, and haven't seen an improvement in corrections.

 

[Slowagon54]

It was the same car, just a day later. Same gas (100 oct), same road, same conditions. I am running an OTS Stage 2 MG Flasher 100oct. map which i top off with meth injection (70M / 30 W) to clean the corrections. To me the logs show a difference like night and day.

Would love to see some others comparison betwen OEM and them.

Also, they caused a shadow code and a long crank on startup to my car. Switched back to OEM and everything was ok again. No codes what so ever.... Never had any issues with the car.

 

[wheela]

It was the same car, just a day later. Same gas (100 oct), same road, same conditions. I am running an OTS Stage 2 MG Flasher 100oct. map which i top off with meth injection (70M / 30 W) to clean the corrections. To me the logs show a difference like night and day.

Would love to see some others comparison betwen OEM and them.

Also, they caused a shadow code and a long crank on startup to my car. Switched back to OEM and everything was ok again. No codes what so ever.... Never had any issues with the car.

This is very interesting, it does seem like very little changed, other than the coils. Between the two logs how do load actual, IAT, and engine & coolant temps compare?

 

[Slowagon54]

Eldor
https://www.spoolstreet.com/graphs/...=10,11,12,18,19,20,21,23,25,34,36&zoom=-2,160

Dinan
https://www.spoolstreet.com/graphs/...=10,11,12,16,17,18,19,21,23,32,34&zoom=-1,148

 

[wheela]

Eldor
https://www.spoolstreet.com/graphs/...=10,11,12,18,19,20,21,23,25,34,36&zoom=-2,160

Dinan
https://www.spoolstreet.com/graphs/...=10,11,12,16,17,18,19,21,23,32,34&zoom=-1,148

Thanks for posting those logs Looks like load actual, and IAT were slightly higher on the Dinan log, but hard to say if it's enough to matter

I haven't driven much since I replaced my original Delphi's with Eldors, but i've already noticed my horrible mileage has gone from the 14's up to 17 and rising. I didn't actually expect to see any improvement, since I wasn't getting misfire codes until I hit a limp mode out of the blue one day, and saw my #2 coil had dislodged from the plug. I'm really anxious to get more miles on these coils and see if the trend continues.

It has me thinking about multi-spark, and at what point the DME considers a misfire to be detected? I know very little about it, but i've read our DME's have multi-spark. I wonder if the DME will register a misfire if it takes the 2nd or 3rd spark to iginte the mixture every now and then? If that was happening, average effective timing advance would be less, as you'd be igniting closer to TDC than per the timing map. Just trying to get my head around how (assuming no misfire codes were getting thrown) changing coils can influence timing corrections, fuel mileage, power, etc.

I've probably had an oversimplified view of the process of igniting the mixture, and misfire detection. At least on my initial log with eldors, my corrections did not look great. Perhaps i'm actually igniting consistently on the first spark now, so actually running per my timing map now vs. closer to TDC than my timing map if I was igniting on 2nd or 3rd spark attempt before

Or maybe I'm totally over thinking this! I'd just really like to understand what's going on here.

 

[Slowagon54]

True. The Dinan Coils had a IAT disadvantage of a few degrees celsius. Not sure if thats enough, but at least something to consider.

Still, the long crank and shadow code remains a mistery.

Wheela, V8bait was quite into this topic, maybe he ll chime in to explain I ll get my popcorn meanwhile...

 

[wheela]

I haven't driven much since I replaced my original Delphi's with Eldors, but i've already noticed my horrible mileage has gone from the 14's up to 17 and rising. I didn't actually expect to see any improvement, since I wasn't getting misfire codes until I hit a limp mode out of the blue one day, and saw my #2 coil had dislodged from the plug. I'm really anxious to get more miles on these coils and see if the trend continues.

Just following up on this, my mileage hasn't improved. After a week or so of normal driving it's back down to 15-ish again.

 

[dfbpurcell]

Does anyone have data on the R35 GTR coil conversion for N54?

 

[Traf]

I could't tell you where i saw a test of R35 coils but they are less poweful than PR's and we know PR's are less powerful than B58.

 

[dfbpurcell]

Thanks for the info. I expected a lot more considering the ridiculous price

 

[Greenie]

Hi, guys, check this: https://bimmerprofs.com/ignition-coils-revolution/

 

[juan_antonio]

@V8bait Confirmations of my thoughts and I'm quite surprised we're not seeing more IGBT failures. The higher inductance of the PR coil is contributing to very high flyback voltages of over 430 V. This exceeds the IGBT's rated collector to emitter breakdown voltage of 390 V. In the stock N54 coil & B58 coil the IGBT is able to quickly clamp the flyback but with the PR coil that isn't the case. If you look very closely at the falling edge of the light blue (IGBT gate voltage) you can see a small step near the bottom of the edge on the PR coil, that appears to be leakage (which make sense since we're above the rated breakdown voltage).
View attachment 49012

Stock N54 Bosch flyback voltage: 344 V (within maximums)
View attachment 49014

Eldor B58 Flyback voltage: 336 V (within maximums)
View attachment 49013

I will be testing more coils tomorrow and hope to have those results added into this post early next week.

@V8bait Confirmations of my thoughts and I'm quite surprised we're not seeing more IGBT failures. The higher inductance of the PR coil is contributing to very high flyback voltages of over 430 V. This exceeds the IGBT's rated collector to emitter breakdown voltage of 390 V. In the stock N54 coil & B58 coil the IGBT is able to quickly clamp the flyback but with the PR coil that isn't the case. If you look very closely at the falling edge of the light blue (IGBT gate voltage) you can see a small step near the bottom of the edge on the PR coil, that appears to be leakage (which make sense since we're above the rated breakdown voltage).
View attachment 49012

Stock N54 Bosch flyback voltage: 344 V (within maximums)
View attachment 49014

Eldor B58 Flyback voltage: 336 V (within maximums)
View attachment 49013

I will be testing more coils tomorrow and hope to have those results added into this post early next week.

I design ignition timing controllers. A client directed me to this old thread, asking if these coils would be compatible with my system on his Supra.

This is excellent data and great scope photos. One minor correction regarding the first photo in post #40:

The small step on the gate signal with 4.2ms dwell is due to the internal protection network of the IGBT being activated.
Refer to the data sheet here: https://www.onsemi.com/download/data-sheet/pdf/isl9v5036s3st-d.pdf

Note the collector voltage has a flat top, indicating it has been clamped by the protection network. Yes, it is higher than the advertised spec, but they would not make the protection network turn on so late as to allow the coil to destroy the part. Evidently the designers have factored in a safety margin between the break-over point of the zener and the fatal breakdown point of the transistor.

The zener breaks down at "some" voltage, allowing current to flow into R1 and R2. The voltage developed across R2 is the small step in the gate signal seen on the scope trace. This step in gate voltage turns the transistor on "just enough" to prevent the collector voltage from going any higher, thus saving transistor. It can afford to gulp down more current, but can't stand more voltage. Note the collector voltage in the two other photos is lower and not flat, indicating the zener has not turned on. To me that's the sign of a wimpy spark. I like to see the flat top, indicating activation of the protection network.

 

[Greenie]

Guys, not so simple.
Onboard voltage. During overrun, it could reach 15+V [and ignition is not interrupted in these conditions; requested voltage could reach 16V]. Higher if outside temperature is less than 8oC and/or AGM battery coded;
Accuracy of measurements. Even for perfectly trimmed/calibrated probe/scope, at higher frequencies, it is lower than +/-5%. In your pics/data, we see a theoretical ''headroom'' of 1..2%.
See Datasheet - dynamic parameters (swich=off time) and its tolerances!
Spike on Gate - Miller's area. Not clear - ''typical'' or intended by clamping circuit. Needs to be measured differently.
Guys, please read the link I sent [and a few more entries about ignition issues].
Triggering of overvoltage circuit results in huge [additional] heating of IGBT. Part of the energy is additionally dissipated in heat, not ''delivered'' to the spark plug.
And finally - max voltage depends on the air gap of the spark plug [higher for a larger gap], pressure in the combustion chamber [higher for higher pressure], peak pressure right after the ignition [depends on ignition angle, fuel mixture], the temperature of ignition coil, etc.

 

[juan_antonio]

Guys, not so simple.
Onboard voltage. During overrun, it could reach 15+V [and ignition is not interrupted in these conditions; requested voltage could reach 16V]. Higher if outside temperature is less than 8oC and/or AGM battery coded;
Accuracy of measurements. Even for perfectly trimmed/calibrated probe/scope, at higher frequencies, it is lower than +/-5%. In your pics/data, we see a theoretical ''headroom'' of 1..2%.
See Datasheet - dynamic parameters (swich=off time) and its tolerances!
Spike on Gate - Miller's area. Not clear - ''typical'' or intended by clamping circuit. Needs to be measured differently.
Guys, please read the link I sent [and a few more entries about ignition issues].
Triggering of overvoltage circuit results in huge [additional] heating of IGBT. Part of the energy is additionally dissipated in heat, not ''delivered'' to the spark plug.
And finally - max voltage depends on the air gap of the spark plug [higher for a larger gap], pressure in the combustion chamber [higher for higher pressure], peak pressure right after the ignition [depends on ignition angle, fuel mixture], the temperature of ignition coil, etc.

Very nice write up. I would like to see the diagram for your snubber.
A few years ago I added code to my single channel "Universal" version to make multiple sparks. It was two weeks of hard fun making it work. As you noted, it creates heat while reducing power at the same time. What a concept. So I shelved it.

 

[Greenie]

schematics of snubber; schematics of coil tester, snubbers for B58 series engine, issues with ignition, etc.:

BMW N series petrol engines ignition coils problems misfires

BMW N series petrol engines N43, N46, N52, N53, N54. ignition coils problems. misfires

bimmerprofs.com

(check part 2..4, too)

Tester of the ignition coils - Bimmerprofs.com | NOx emulator NOXEM 129 | 130 | 402 developed for BMW N43 & N53 series engines

Taking in the account, that many readers of my blog have inquired regarding the schematics of the tester of ignition coils, you will find it below: The tester itself is in the center of the screen, diagnostics probe hubs for automated (manageable from PC) solution are placed on the […]

bimmerprofs.com

B58. Ignition. Total failure - Bimmerprofs.com | NOx emulator NOXEM 129 | 130 | 402 developed for BMW N43 & N53 series engines

It is hard to count the decades since Siemens and Bosch developed DME for the petrol engines. The primary things should be in order! Would it be logical? Yes, it would! Well, let’s see how is Bosch, with the latest MEVD 17.2.9 management installed on the B58 series engine, doing. […]

bimmerprofs.com

etc.

 

[juan_antonio]

I have it on good authority the BOSCH B58 coil is an ELDOR B58 with a BOSCH sticker.

 

[Greenie]

confirmed!

B series engines. Ignition coils. Bosch - Bimmerprofs.com | NOx emulator NOXEM 129 | 130 | 402 developed for BMW N43 & N53 series engines

This time – a short review of the Bosch ignition coil.Code of the ignition coil: 0 986 221 124 The ignition coil is delivered in a nice Bosch box: Electrical parameters of the primary winding. BMW vs Bosch.Inductance: 1.10/1.15mH (+5%)The active resistance: 410/330mOhm (-20%) This ignition coil...

bimmerprofs.com

 

[Traf]

I have it on good authority the BOSCH B58 coil is an ELDOR B58 with a BOSCH sticker.

The initial testing done in this thread seems to directly contradict this.

 

[juan_antonio]

Yeah, my associate in Germany thought that was funny:

"The funny thing is, that the BOSCH coils are the very same ELDOR coils.
I know the company that applies the BOSCH stickers to the ELDOR coils, here in Germany.
Even more funny, I tested and released the Bosch coils for that company."

 

[Greenie]

The initial testing done in this thread seems to directly contradict this.

??? no. not correct.