Quote:
Originally Posted by thejeremyman9
Quote:
Originally Posted by socalengineer
But I am running more boost and timing? Bootmod3 recommends NGK 97506:
https://bootmod3.atlassian.net/wiki/...+and+which+gap
I am also tuning a friends car, N55 PWG, with a Pure Stage 2 Turbo. They are running the NGK 97506 as well, just wondering if there is a better option. |
Yes, i know what BM3 says, which is why so many people blindly follow that advice and swap in colder plugs with a smaller gap that they don't need.
My 45k mile OEM plugs did fine at E30 before i changed them and replaced with new OEM... also people run OEM plugs with PS2, meth, etc all the time.
Quote:
Originally Posted by lucasborka
Stock is the way to go.
Bosch ZR5TPP330 at stock gap. You want the biggest gap possible without spark blowout for a more complete combustion. Better combustion better power
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Correct |
I've got Bootmod3. A few years ago they recommended NGK 97506 gapped down to 0.022" for their N55 Stage2 tunes. Later they came out with that spark plug article that makes it sound like they recommend them for all of their N55 tunes, including Stage1.
I contacted them and pointed out that by default a Stage1 tune is supposed to mean that the hardware is all stock. (Except of course for the poorly designed F30 N55 chargepipe) As far as I know they ignored my suggestion to clarify that stock plugs & gap should used for BM3 Stage1.
Guys are so used to looking for and assuming that every part has an upgrade. There is no such thing as a spark plug upgrade! BMW engineers chose the stock plug and gap because it provides optimal performance for the engine.
With spark plugs- if it ain't broke don't fix it. If it's running fine, then there's no upside to changing plugs/gap. It can't get better. It can only get worse!
"Spark blowout" was mentioned as a reason for different plugs/gap. Spark blowout is actually a misnomer. The spark doesn't blow out. It never gets started. It can happen with very high boost tunes because they jam a much higher than usual number of fuel and air molecules into the engine cylinder. It creates a traffic jam of sorts. One solution would be electronics with a stronger spark like a race team might do, but it's easier to switch to a colder plug with a shorter gap. But there's often a trade off. For example an engine may not idle as smoothly.
For a newly tuned N55, I would suggest installing a set of new stock Bosch plugs at stock gap out of the box. There are about $9 each. Then see how it runs. Learn how to collect logs. If there are issues never suspect plugs first. Always make sure that fuel quality is high enough. If local 93 gasoline quality is suspect then add 1-2 gallons of E85 to the tank. Or flash down from the 93 tune to the 91 Octane tune. If those things improve engine smoothness and performance then it's fuel quality not a spark plug issue. There are plenty of posts about how to visually inspect plugs to determine how an engine is running.
Hope this helps someone!