B58 coils to S55

[Tommix]

Now that MHD released NXM B58 Coils flash option for S55 I could move to B58 coils. My plan is to buy thease:
https://nexsysmotorsport.com/n-s55-i...l-upgrade-kit/
and used coils fom ebay.
But what about spark plugs, is NGK SILZKGR8E8S (from S58) the right one?

[TR930]

What are you hoping to gain by making this switch?

[TopJimmy]

Delphi brand OEM coils are good for at least 1K WHP.

How does the MHD swap improve on this?

What are the downsides or gotchas?

____________

To your question of which plugs, you use the plugs matched with the motor. That's OEM BMW for stock, the NGK D8S (97506) for tuned, and the BMW F8S FlexFuel Plug for hot tunes. You want the plug's heat rating to match the motor fuel and power level (actually the heat level at the plug). Plugs for higher power engines get more heat protection from a higher collar around the ceramic. This is why they are commonly called 1-step (D8S) or 2-step (F8S) "colder". A plug run within the proper heat range burns clean without tip buildup, but a too hot or cold plug leaves soot or fouling buildup.

For 90% of tuned S55s the NGK 97506 gapped 0.021"-0.023" works very well, and has a change interval of 15-30K miles. OEM coils last 100K or until they die, thats per a BMW master mechanic.

[Tommix]

Currently i have E50% custom tune. Logs are ok, but I have some issues in hi rpms. Sometimes in hard push (wot) there is some twitching/jerking (I don't know the right word for this, sorry) after 6000 rpm. There is new NGK 97506 sparks (gap 0,02") + new OEM coils. I am also preparing to change the injectiors.
Mods: catles DP's, MHD custom tune, xHP
2014 model and ~ 40 000 miles
log:
https://datazap.me/u/tommix/e50-mult...og=0&data=4-24

And why B58 coils, B58 coils are capable of producing more than 2x the energy output while providing a longer spark duration than the N55/S55 coils.
Just wonder if this mod might help me in this case?

[hellokitty]

Originally Posted by Tommix

Currently i have E50% custom tune. Logs are ok, but I have some issues in hi rpms. Sometimes in hard push (wot) there is some twitching/jerking (I don't know the right word for this, sorry) after 6000 rpm. There is new NGK 97506 sparks (gap 0,02") + new OEM coils. I am also preparing to change the injectiors.
Mods: catles DP's, MHD custom tune, xHP
2014 model and ~ 40 000 miles
log:
https://datazap.me/u/tommix/e50-mult...&data=4-24

And why B58 coils, B58 coils are capable of producing more than 2x the energy output while providing a longer spark duration than the N55/S55 coils.
Just wonder if this mod might help me in this case?

F8S flex fuel plugs would be the first thing I would do in your case. I'm on full E85 and these plugs are a must for ethanol blend vehicles.

OEM coils are fine to use. Spark plug choice is way more essential.

[Tommix]

Originally Posted by hellokitty

F8S flex fuel plugs would be the first thing I would do in your case. I'm on full E85 and these plugs are a must for ethanol blend vehicles.

OEM coils are fine to use. Spark plug choice is way more essential.

Thanks for this information. Flex fuel plugs gap is still 0,02"?

[hellokitty]

Originally Posted by Tommix

Thanks for this information. Flex fuel plugs gap is still 0,02"?

Yes gap to .020