Technical BL Coil Investigation and Solution

[JimboFresh206]

You don't need to bypass the drivers in the DME with a 3 pin inductive coil afaik (use PR as an example) you just disable multispark to allow for more dwell time. You can also supply the coils with a dedicated 12v source to unload the DME a bit, but most drivers can handle 30A some standalone's upwards of 40A.

The issue with the R8 coils is that the signal has to be 5v square "high" signal to trigger the driver in the coil itself. The DME provides this signal to the drivers inside of it, but the drivers do not output the same square 5v. They send a "Low" signal switched ground telling the coil to charge/discharge, hence the harness/chip-set to alter the signal from the drivers and the harness also provides the coils with a dedicated 12v that isn't drawn from the DME. Over on bummer-boost there was a bit of dissection on the signals and the BL harness itself.


no trolling, just want to be able say I have GTR parts bro

 

[Rob09msport]

You don't need to bypass the drivers in the DME with a 3 pin inductive coil afaik (use PR as an example) you just disable multispark to allow for more dwell time. You can also supply the coils with a dedicated 12v source to unload the DME a bit, but most drivers can handle 30A some standalone's upwards of 40A.

The issue with the R8 coils is that the signal has to be 5v square "high" signal to trigger the driver in the coil itself. The DME provides this signal to the drivers inside of it, but the drivers do not output the same square 5v. They send a "Low" signal switched ground telling the coil to charge/discharge, hence the harness/chip-set to alter the signal from the drivers and the harness also provides the coils with a dedicated 12v that isn't drawn from the DME. Over on bummer-boost there was a bit of dissection on the signals and the BL harness itself.


no trolling, just want to be able say I have GTR parts bro

What's nice is boots being replaceable and they seem like lifetime coils. They are expensive though. All those kits were saying smart conversion I couldn't find clarification if they were going to or from but the fact they bypass the factory igniter and that I don't see any heatsinks leading me to believe their is no mosfets in the harness hence smart coil built in ignitor. I know someone reading knows and Is just dying at how clueless I sound .

 

[JimboFresh206]

I can get them a bit cheaper wholesale, but you can also find them from dealers/there online pages for around $110 a pop. The PR kit makes the most sense IMO but I have an m18 valve cover and don't want to use plugwires.

If I get around to it I'm hoping the r35 coil boots can be used, or the bremi boots from the m5x engines maybe? Still just kicking this one around.

 

[V8bait]

So pr are much more powerful? I thought the r8 had higher voltage but pr more output. Also do you know what the stock coils output?
Last would you Ever recommend anyone upgrade from bl to pr ? I know people were getting away with larger gaps on bl at one point but if pr has better duration I should think that would make more power and cleaner burn.

Power is relative in this instance. R8 does make higher voltage potential, PR and AEM have higher output but with lower voltage potential. The voltage the coil is fired at is based on gap and cylinder pressure, it fires at whatever that ends up as. The energy remaining burns as spark duration and intensity you could say. If the conditions demand higher voltage than a coil can produce, it will not fire. R8 can hit such high voltages that this can be an issue and they will discharge internally and cause self damage, side effect of small size and not enough insulation on the coil bits.

GTR coils iirc the r35 is a smart coil like the R8, so the ignitor is built in. If somebody wanted to spend some money they could make any of these designs dumb and run off the dme igniter instead of using an expensive harness, but if you're digging into a coil (like PR did) there's no reason to limit yourself to the OEM design specs.

R8 is a pretty solid coil compared to the BMW one, GTR is better but also more expensive and you'd need to fabricate a new bottom section to use them, where R8 kinda mostly fit right in. R8 wasn't a bad choice at all for a factory coil, ideal well we all have ideas on that.

 

[Rob09msport]

Mic dropped
Just playing but he basically summed it all up real quick lol

 

[JimboFresh206]

Ok cool that makes sense, I assumed only having 3 pins that they were just inductive pencil type coils.

It would be cool if someone offered a BL style harness but had something like this (if it would even work) in a box you could stuff near the DME instead of in the plug housing -.-

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It also would be cool if PR made a bracket that worked with the m18 VC

 

[Rob09msport]

The only thing that confuses me is how do we control dwell with r8 coils if they are smart
Like I thought true smart coil saturates and then is ready to fire but apparently not.
And if someone wanted I'm sure could just depin and repin with longer wires to make the bl harness go in box and then have seperate power harness and signal harness running to the coils.
You can tuck the converters under the fuel lines tho that's what I do.

 

[Rob09msport]

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Their Is a smart version of the ign 1 coils but i guess it's not nec since they are .5 ohm so matches to dme. It shows how redundant the 5 wires are tho really only need 3. Not sure what the sensor wire does. Also some dumb coils are only 2 wire afaik.

 

[veer90]

I continue to have people contact me with issues with the bimmerlife ignition systems having misfires. The latest conversation - the owner was told by bimmerlife Tuning's owner that modifying the stock R8 coils is unnecessary. It is amazing to me, given what has been measured and clearly demonstrated, that the vendor would either ignore the information or worse, mislead people in the name of sales. I'm happy to help other people in the community - but being bimmerlife tunings technical support department is not what I had in mind.

My advice, after countless emails and PMs over the past year - don't buy products from a vendor that either doesn't understand what they are selling, or willfully misleads.

Filippo

If you do the mods to properly seat the coil BL works and the R8 coils make serious jam with big plug gap.

But 100% agree the way Alex is advertising them is a joke. I'd say willfully misleads.

He should be replacing the trash gen 1 harnesses for free but instead he wants to charge.

 

[Rob09msport]

Think it's time to pull this thing apart and print in high temp abs or buy bmw and r8 connectors to make harness and just make conversion box.

 

[Panzerfaust]

Think it's time to pull this thing apart and print in high temp abs or buy bmw and r8 connectors to make harness and just make conversion box.

The 2.0 harness is pretty sturdy in my experience actually. It's survived me yanking on it in the cold ass Chicago winter weather when several OE BMW things haven't. Maybe I'm wrong but I thought that the v2.0 harnesses were made by NRW in order to increase the quality - maybe I'm thinking of a different product though.

I'd say if you're going to go through the trouble of making your own harness and conversion box, you should make it for something like the AEM smartcoils or other similar setup. The fact that the BL coils have been around for so long and that so many people think they're fine without modification (until they dont...) makes me think people would still likely continue to just purchase BL coils because youd be the "new guy on the block" and satan knows the N54 community doesnt like any newcomers for a good while.

 

[Rob09msport]

I dont want to make money I would simply share the file for the print and figure out the conversion then you can use any could you want with the proper connector either printed or purchased

 

[V8bait]

The only thing that confuses me is how do we control dwell with r8 coils if they are smart
Like I thought true smart coil saturates and then is ready to fire but apparently not.
And if someone wanted I'm sure could just depin and repin with longer wires to make the bl harness go in box and then have seperate power harness and signal harness running to the coils.
You can tuck the converters under the fuel lines tho that's what I do.

Dwell control is the same for all coils. Dme 5v high side signal is the dwell. In OEM and PR, that signal hits the igniter chip in the dme, and cycles the ground which cycles the coil directly. In most smart coil setups, that igniter chip is moved to the coil itself, that's all. In the BL kit, dme 5v signal goes to factory igniter chip, then BL harness reverses it from a ground to a 5v high signal with a few chips (voltage regulator to step down 12v to 5v, transistors to gate the 5v based on the low "signal" from the dme), then that gated 5v goes to the ignitor chip on the coil itself. Same idea just many more parts, dwell still controlled by dme.

Some ignitors have safeties for current limiting and dwell protection. Certain GM ones will discharge if dwell is too long. That's all. As for wires, you only need 2 in dumb coils (12v, primary ground which is cycled to charge). The third is for an alternate secondary ground (the plug itself should ground but whatever). Smart coils at minimum need 12v, primary ground (for the internal ignitor to gate/emmit to the coil), then also needs 5v signal, and 5v signal ground (low noise ground back to dme). You can get away combining the two grounds but it's cleaner not to. You can also get away with sending 5v static and switching the signal dme ground with the OEM low side signal, but it's very iffy and coil output suffers significantly for some reason.