N54 | Ignition System Maintenance
Since you came to this page, you might be questioning your life choices after purchasing a BMW. She might not drink oil but she will burn through spark plugs, ignition coils and everything that is located around the engine. One thing, this car is fun, so most people will tune the living god out of this "German 2JZ". We are going to cover two pieces of ignition system and also, three types of applications for those components since they will differ for stock and for tuned cars, as well, as heavily moded ones. To get the most bang for your buck and the most performance out of the car, this is the best guide to follow.
Stock Cars - Stage 1 Tune
Whether you are stock or have DCI (dual cone intakes) instead of the plastic BMW box, you most likely will opt int for Stage 1 tune and "be done", right ? WRONG! Once you're in, you're hooked. This is where the fun starts and your wallet leaves the chat room.
The stock ignition coils are rated for 30-50,000 miles and spark plugs are rated for only 30,000 miles, however most people don't ever change them and you get something that looks terrible and performs even worse. (See the picture below)
Prime example of what spark plugs after 100k miles (160k kilometres) look like.
Expect to pay $8-$11/each
Don't expect the car to perform well, tuned or not, it will misfire, cause shakiness on idle and unfortunately possibly even damage piston rings. Now, the last one is extreme, considering the N54 is built to withstand a nuclear bomb but if left in such condition, I wouldn't be expecting smooth ride. The best replacement for the stock plugs are generic OEM ones from Bosch. Considering Stage 1 cars, I would go for NGK 95770(old part #), which were replaced by NGK NGK 97968(new part #, same spark plug). There were minor changes to NGK Spark plug revisions, however they are pretty much the same ones.
These are NGK 97968 (NGK 95770) spark plugs. Best when gapped to 0.022" (0.56mm) for stock and Stage 1 tunes.
Expect to pay $12-$15 each
The coils are completely different animal, as it is hard to tell when they were replaced or if they are new, unless you did it yourself. As a good rule of thumb, replace your coils when you replace your spark plugs for the first time. It is a good practice to always replace these components when buying an N54. The only excpetions should be is when you are 1000% sure that the privious owner swapped the coils not long ago. For stock cars and Stage 1 Calibrated, refer to OEM set of coils, as they are just fine up to 600 whp.
These are OEM coils and can be used for applications up to 400 WHP (460 HP).
Expect to spend around $200/set.
But what about heavily tuned and modified cars ?
Story isn't much different for stock turbo cars, besides the change to the gap on
the NGK 97968 plug, it should be set to 0.020" (0.5mm). In some cases people swap the OEM coils to Eldor or Delphi (N55 manufacturer for coil packs), however there really is no need to spend the extra money. I have personally ran stock coils and NGK plugs at 670awhp (my 335xi) without any issues whatsoever.
Hybrid Twins | Single Turbo - Low Boost
Now we are getting into "Fun zone," which means, basically expect sh*t to break. Even at above 500 whp (580hp) power levels, you should see no significant gain in performance or have any benefit from going from OEM Coil packs to aftermarket Percision Raceworks or BimmerLife setups. Plugs, however should be NGK97968 (1 step colder) or you should start considering new set, which are NGK 97506 (2 step colder). Gap shall remain unchanged, at the 0.020" (0.5mm) mark.
These Spark plugs do not look much different from NGK 97968 (NGK 95770), however the electrode inside, makes all the difference in the world.
Expect to spend $13-$18/ each
Hybrid Twins | Single Turbo - High Boost
The "fun season" has been cracked open and now your fuel economy looks like "smiles per gallon," that is "TERRIBLE," for my European friends. Expect to rehaul you entire ignition systems. Stock coils or somewhat resistant ones from Eldor and Delphi are just trash at this point. Anything that is over 25psi of boost is basically a "Misfire City" for anyone trully pushing their cars within every aspect of tuning (aka. timing, fuel, vanos... more on those later). For these applications start looking into upgraded coils such as Precision Raceworks (PR) and Bimmer LIFE (BL). Those come at steep price, however you will have a smooth runing car with turbo whistles and freshly burn rubber smell, every day... until something else breaks.
These are pretty much pinnacle of the ignition system for N54. Anything above 600WHP is suggested to have these, anything above 700WHP should have these installed... no questions asked.
Expect to spend $500 USD for the whole kit.
Similar kit, however these are R8 coils. There are plenty of tutorials how to build one yourself. I wouldn't spend $500 on this, you can spend about $300 and build it yourself
DYI Cost: $280-$330 Buy New: $500
I hope you enjoyed my simple write up on "Ignition system" and what you should have installed at which power levels. If you have any questions, don't hesitate to shoot me a message on Telegram or WhatsApp. Donations are Welcomed and will buy me a beer, or two.
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