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

[Lightning]

the B58 and PR coils are definitely an upgrade over the R8 coil.

Thanks for testing these out! But how do you come to this conclusion? The other coils where not tested at the same dwell time and the R8 coil was not tested at dwell times above 2.5ms. I bet is that the R8 will also score very high when dwell is increased as they do not differ much from the B58 coil.
The R8's perform better at 2ms dwell than the PR's at 3ms!

My bet is that R8's at 3.2ms dwell will also result in a top 3 finish. Meaning R8's are probably the coils to buy. At least over the PR's because R8's pull no current through the DME. This could potentially mean that the PR's perform like this with a clean power supply in the test but might not reach this performance in real life because of DME current limitations?

 

[bahn]

Thanks for testing these out! But how do you come to this conclusion? The other coils where not tested at the same dwell time and the R8 coil was not tested at dwell times above 2.5ms. I bet is that the R8 will also score very high when dwell is increased as they do not differ much from the B58 coil.
The R8's perform better at 2ms dwell than the PR's at 3ms!

My bet is that R8's at 3.2ms dwell will also result in a top 3 finish. Meaning R8's are probably the coils to buy. At least over the PR's because R8's pull no current through the DME. This could potentially mean that the PR's perform like this with a clean power supply in the test but might not reach this performance in real life because of DME current limitations?

The R8 coils are saturated at 2.5 ms. They cannot be safely dwelled longer without overheating (literally melting). The PR and B58 coils both out perform the R8 coils.

 

[Lightning]

Ah that explains some.

I am correct to say that the dwell range of our DME is limited from 1 to 3.5ms? (Source: http://www.bm-parts.com/index.php?route=product/product&product_id=52)

That would mean the R8 still outperforms the PR coils.

 

[bahn]

Ah that explains some.

I am correct to say that the dwell range of our DME is limited from 1 to 3.5ms? (Source: http://www.bm-parts.com/index.php?route=product/product&product_id=52)

That would mean the R8 still outperforms the PR coils.

No the DME is not limited to 3.5 ms dwell.

 

[Lightning]

Awesome. Learning something every day.

Do you happen to know the dwell times for the PR and R8 coils that's behind the MHD checkboxes?

 

[tony@codewerx]

The dwell time is not limited to 3.5ms. In fact it can go up to 20.

It varies on charging voltage. Most N54s run typically around 13.6 - 14v.

I’ve enabled igr for my alternator and so it varies between 12 -15v.

So dwell times varies accordingly...

I am not sure if the MHD checkbox for B58 coils is going to work well with this setup If the focus is just the 14v column.

Does anyone have the B58 engine dwell table ? This should give us an idea how bmw views the dwell times on that engine with those coils.

 

[Jeffman]

I’ve enabled igr for my alternator and so it varies between 12 -15v.

What’s this?

 

[tony@codewerx]

What’s this?

igr - intelligent alternator. Feature found in m3 and the f series. Charges your battery only when your foot is off the pedal. When accelerating it frees Up a few ponies by not being a drag to the crankshaft ...

 

[V8bait]

The n54 dwell tables can and should be set for all the voltages from around 8v to 20v or whatever the axis is. It's very easy to get the values by varying voltages on the test bench, no need to copy factory tables. R8, PR, B58, OEM are all tuned properly for any voltage with MHD.

N54 DME can run any dwell you want really and obviously unloading the dme from the coils (be it for B58 or PR) isn't very important. The INJECTOR mosfets in msd80 (the parts that fail) won't care about the added stress on the IGNITION system, they fail completely independently. R8 "unloads the DME" sounds nice for marketing (and is nice, sure), but when I have tortured my set of PR running overcharged at 6ms dwell perfectly stable for over a year, it's just not necessary. You add more unreliability and failure points with the R8 for less powerful spark. Been saying that for years. They're red though, and come in sports cars, so nobody cares about facts I guess.

I think overall the B58 is a winner for stock location and being generally perfectly matched to the car, PR is winner for squeezing every last mJ and higher voltage potentials if you need it, or to remote mount for heat issues. I don't see much use for R8 or GTR options with B58 and PR running off the DME.

 

[tony@codewerx]

Aftermarket coils - bench testing would provide guidance on setting the dwell value - understandable.

BMW have to do the same thing as well - that they did properly tune the dwell based on charging voltage specifically for those b58 coils.

 

[bahn]

The dwell time is not limited to 3.5ms. In fact it can go up to 20.

It varies on charging voltage. Most N54s run typically around 13.6 - 14v.

I’ve enabled igr for my alternator and so it varies between 12 -15v.

So dwell times varies accordingly...

I am not sure if the MHD checkbox for B58 coils is going to work well with this setup If the focus is just the 14v column.

Does anyone have the B58 engine dwell table ? This should give us an idea how bmw views the dwell times on that engine with those coils.

The n54 dwell tables can and should be set for all the voltages from around 8v to 20v or whatever the axis is. It's very easy to get the values by varying voltages on the test bench, no need to copy factory tables. R8, PR, B58, OEM are all tuned properly for any voltage with MHD.

N54 DME can run any dwell you want really and obviously unloading the dme from the coils (be it for B58 or PR) isn't very important. The INJECTOR mosfets in msd80 (the parts that fail) won't care about the added stress on the IGNITION system, they fail completely independently. R8 "unloads the DME" sounds nice for marketing (and is nice, sure), but when I have tortured my set of PR running overcharged at 6ms dwell perfectly stable for over a year, it's just not necessary. You add more unreliability and failure points with the R8 for less powerful spark. Been saying that for years. They're red though, and come in sports cars, so nobody cares about facts I guess.

I think overall the B58 is a winner for stock location and being generally perfectly matched to the car, PR is winner for squeezing every last mJ and higher voltage potentials if you need it, or to remote mount for heat issues. I don't see much use for R8 or GTR options with B58 and PR running off the DME.

B58 dwell is handled in a different manner but I extrapolated the values over to the N54 table type and fully populated it so you're good to go @tony@codewerx

 

[Torgus]

They're red though, and come in sports cars, so nobody cares about facts I guess.

This.

I have been saying this for years PR needs a red color option. I swear it's the only reason people buy the inferior R8 coils which don't fit and have to be modified.

@bahn find a way to get B58 coilpacks in red and you will be in the money.

Seriously, even heat shrinked red vinyl would probably work. Make it red, shiny if possible. That is what 'the people' want. Hell a rattle can might even do it for the instagram fuk bois.

 

[V8bait]

Aftermarket coils - bench testing would provide guidance on setting the dwell value - understandable.

BMW have to do the same thing as well - that they did properly tune the dwell based on charging voltage specifically for those b58 coils.

How do you think they determine the dwell? They do it by measuring the point of situation, at various voltages, and at various temperatures. The tables are available for the B58 all I'm saying is that it's not really necessary if you have proper testing equipment. It's like saying you need to use BMW values for tire pressure when installing M4 wheels on your 335i (bad example but you get the point).

 

[tony@codewerx]

How do you think they determine the dwell? They do it by measuring the point of situation, at various voltages, and at various temperatures. The tables are available for the B58 all I'm saying is that it's not really necessary if you have proper testing equipment. It's like saying you need to use BMW values for tire pressure when installing M4 wheels on your 335i (bad example but you get the point).

Great if you have the test equipment ... if not bmw is an ok source for reference.

 

[_Calle_]

This.

I have been saying this for years PR needs a red color option. I swear it's the only reason people buy the inferior R8 coils which don't fit and have to be modified.

@bahn find a way to get B58 coilpacks in red and you will be in the money.

Seriously, even heat shrinked red vinyl would probably work. Make it red, shiny if possible. That is what 'the people' want. Hell a rattle can might even do it for the instagram fuk bois.

Thats the way APR goes

 

[Lightning]

I have been saying this for years PR needs a red color option. I swear it's the only reason people buy the inferior R8 coils which don't fit and have to be modified.

Lol! These coils have been proven over and over (and again in this topic) to perform great with double the energy of a stock coil. 800hp+ capable. Modifying them is a one time action taking less than 1 minute per coil.
They do not require a plate or cutting the engine cover. They are the cleanest best looking option to date.

 

[rev210]

Lol! These coils have been proven over and over (and again in this topic) to perform great with double the energy of a stock coil. 800hp+ capable. Modifying them is a one time action taking less than 1 minute per coil.
They do not require a plate or cutting the engine cover. They are the cleanest best looking option to date.

Fair to say they used to be a good option before now. Subjective looks winner perhaps? Although modified they still dont fit perfectly and the 3d printed connectors arent inspiring quality, there is a thread dedicated to investigating this in detail.

Beyond that ,even after the brilliant testing in this thread, I'm still on the fence about 'needing' an upgrade (of any kind) over the eldor revision of the N54 coil. We can definately see the power of the B58s but, what empirical benfit does it impart to real world performance (something worth investigating). As people with big power single turbos are also running eldors and delphi stockers without issues. I even ran 10s with the orginial bosch coils .One only recently packed in so I now have eldors. I didnt see a good reason to go PR or R8.
How do we properly weigh the value?

 

[V8bait]

Fair to say they used to be a good option before now. Subjective looks winner perhaps? Although modified they still dont fit perfectly and the 3d printed connectors arent inspiring quality, there is a thread dedicated to investigating this in detail.

Beyond that ,even after the brilliant testing in this thread, I'm still on the fence about 'needing' an upgrade (of any kind) over the eldor revision of the N54 coil. We can definately see the power of the B58s but, what empirical benfit does it impart to real world performance (something worth investigating). As people with big power single turbos are also running eldors and delphi stockers without issues. I even ran 10s with the orginial bosch coils .One only recently packed in so I now have eldors. I didnt see a good reason to go PR or R8.
How do we properly weigh the value?

That's a fair question. Most people do see a small bump in midrange power upgrading from the OEM coils to PR and R8, we'll have to see some dynos but I'd expect gains with the B58 as well. This has been well documented and is likely due to better combustion as the other options (PR and R8) have been shown to allow modestly larger gaps at higher power. B58 will hopefully follow suit.

Some people upgrade for aesthetics, reliability, or because of heat/turbo placement concerns as well. Tony liked being able to grab an RPM trace off a plug wire on the dyno easier for his hundreds of pulls. I don't think coils should be a primary focus for anybody unless you want them or feel you're being limited by factory ignition (IE gap below .020", combustion misfires that always resolve with fresh eldors but only for a few weeks/months).

 

[STE92]

My question is at what dwell are the PR/R8 and B58 being set by MHd?

 

[bahn]

My question is at what dwell are the PR/R8 and B58 being set by MHd?

They all vary depending on RPM. Earlier in this post I provided this information: Peak R8 dwell 2.5 ms, Peak PR dwell 4.8 ms, Peak B58 dwell 3.2 ms.