[tenkies]

I had a hard time finding a definitive answer on this. I'm going to be updating to a BM3 stage 1 tune. I have all the FBO mods to go Stage II but with the shitty CA gas I'm a little hesitant to use the OTS tune and would rather get a custom tune for stage II and will definitely upgrade plugs for that but is replacing the stock plugs necessary for stage I? I only have 12K on the odometer right now.

[ZM2]

Stock plugs, stock gap.

As F87source will tell you, you don’t even need to change plugs for a Stage 2 custom setup.

[VisualEcho]

Originally Posted by tenkies

I had a hard time finding a definitive answer on this. I'm going to be updating to a BM3 stage 1 tune. I have all the FBO mods to go Stage II but with the shitty CA gas I'm a little hesitant to use the OTS tune and would rather get a custom tune for stage II and will definitely upgrade plugs for that but is replacing the stock plugs necessary for stage I? I only have 12K on the odometer right now.

I've got good gas in Missouri, but I'm still a bit worried about using an OTS Stage 2 tune. Where are you getting your custom tune from?

[tenkies]

Originally Posted by VisualEcho

I've got good gas in Missouri, but I'm still a bit worried about using an OTS Stage 2 tune. Where are you getting your custom tune from?

Still deciding on that. Ideally I'd like to find a local tuner with a dyno. I'm going to monitor what stage I looks like before worrying about stage II. I really would like to stay running on pump gas and not worry about mixing E85 or race gas just to drive around daily.

[F87source]

Originally Posted by ZM2

Stock plugs, stock gap.

As F87source will tell you, you don’t even need to change plugs for a Stage 2 custom setup.

+1

Start with stock plugs with stock gap if mileage is high replace them, if you're misfiring then look into a smaller gap if it's plug Induced misfires - unlikely at stage 2 power levels in a stock turbo.

For heat range changes read the plug. But honestly you shouldn't need a colder plug till 700 whp.

[carchrism5]

One thing to note is that in a lot of the BM3 threads you'll see people recommending "one stage colder" for N55s, but keep in mind the M2 N55 already runs colder plugs than standard N55s. So as stated above, run stock and log, if mileage is high change them. But unless a tuner looks at your logs and tells you to swap to a different plug on the M2 stock is fine.

[F87source]

Originally Posted by carchrism5

One thing to note is that in a lot of the BM3 threads you'll see people recommending "one stage colder" for N55s, but keep in mind the M2 N55 already runs colder plugs than standard N55s. So as stated above, run stock and log, if mileage is high change them. But unless a tuner looks at your logs and tells you to swap to a different plug on the M2 stock is fine.

Here is what I posted on another thread:



"Ok so you have 2 real options for spark plugs:

1) The OEM bosch plugs which are totally fine to use in high power level situations, and their heat range is also fine up to 700 whp. Now the part number is Bosch ZR5TPP330A (the A version iirc is the updated one that doesn't crack there was TSB on this).

With Bosch plugs the 3rd digit is the heat range so this has a bosch heat range of 5 which is equal to NGK's heat range of 7.

2) NGK 97506 the ngk heat range of this plug is 8 which is equal to a bosch heat range of 4. This plug is 1 step colder than the m2 n55/s55 stock plugs and 2 steps colder than the stock n54 plug.


With plugs like I said earlier no need to go colder for no reason as it can lead to bad combustion, but that doesn't seem to be an issue on these cars so it is your choice which option you want. For me I am happy with the stock plugs and they are also 1/4 the price of an NGK so i'm also saving money in the process. But do not let money savings prevent you from doing what is right for your car, if your car calls for it go for what it needs - but since I don't see many high 600whp-700 whp m2's there really is no need for it (it's like buying botique oils for no reason). Also remember to read your plugs when you change them to see if you do need to go colder, that is always the key to moving heat ranges, the 700 whp number is just a guide line it is always best to read your logs and plugs to determine if you need to switch - just like you would with a used oil analysis.




For gap start with the stock 0.028" gap and move your way down until the misfires stop. If you go too small you will get incomplete combustion and misfires and rough idles. Too big and your spark will blow out and the same misfires will occur at high boost conditions. Generally speaking mid 400 whp you won't have an issue with stock gap as that is where the m4 gts and m2cs are running. But since you are at 500 whp and with old plugs this could be a sign you need to get new plugs (tuned cars should get it ever 20k miles or less, and every 4 years as per bmw).



If you gap gets too ridiculously small like smaller than 0.022" then you probably should get upgraded coils. For the S55 there are no offerings yet (because of the air to water intercooler) - but this will change when nexyus makes the B58 coil conversion for the S55. This will be the best offering yet because the B58 coils make more power than the precision racewerks kit with less dwell, more spark duration, all while heating up the IGBT on the ecu less meaning better life time for that component. So wait on that kit.

But honestly you can get coils on a stock car too if you want, it just depends on if you want to spend money for no reason or not. Personally I would consider getting coils at a spark gap of 0.024" or less, but if you really don't want to spend alot of cash on a coil upgrade you can push it to 0.022 or less or whenever decreasing your gap sizes just don't cut it anymore and you keep misfiring no matter what. Remember our delphi coils are already more powerful than the stock n54 coils and those guys run upgraded eldor coils (same power output as our delphis so don't waste your money switching to those) for super high power builds so there really isn't a huge need to upgrade coils prematurely.


So let me sumarize this last part because it was likely convoluted because I like to ramble:

1) If you have money to burn upgrade coils even on a stock car - why not. (If you have alot of money consider giving me some lol JK donate it to charity or something, or save it for the future I am ok).

2) If you really want to optimize your ignition setup and rather spend money here over an exhaust, colored engine cover or whatever, (a really good idea compared to the former) upgrade when your gap size gets to 0.024" or smaller.

3) This one over rides all of the above, when you begin to continue to gap down but it doesn't solve your misfires at high rpm. Or your small gap size at high rpm works fine but low rpm it starts to stumble you should get upgraded coils so you can run a bigger gap at all times.


Hope this helps, and you probably should change out your plugs soon. On a used car I normally do all the belts, fluids, plugs, filters, brake fluid and pads even if not required."