NGK Spark Plugs for Modified Engines, BMW M50/M52/S50/S52

Despite the claims of other "fancy" types of plugs, these have shown the best performance on the Dyno as well as a smoother idle and plenty of lifespan.

Under hard performance driving conditions, and or boost- checking spark plug gap and/or replacing these plugs on a regular 20-35k mile intervals is recommended for best results.

We always keep these in stock for whenever you need them!

Plug shown in images is for example only, it is of the OE plug

VAC Tech Tips:
-These plugs work well for bolt on turbo charged M5x/S5X and many supercharge apps.
-These plugs are 1 heat range colder than 96-99 OEM specs
-Gap is .32 stock, you may set gap at .28 for best results with higher boost levels
 

Why these plugs? If the heat range of your plug is not optimal, then fouling of the plug or at the other end of the spectrum- pre ignition / detonation can occur. Very problematic on modified applications. Optimal firing-tip temp is obtained between an approximately between 930°F and 1475°F and if the temperature varies too high or low from these temps, carbon fouling or plug over heating (and possibly plug failure or engine internal damage) can be the result. While they sound non-exotic, most often copper plugs with a nickel plating are an excellent choice for this application. Their thermal/electrical conductivity is excellent, and copper has the ability to dissipate the heat after firing very efficiently. Some may recommend Silver plugs and while it's an excellent material to produce a strong spark with very good thermal conductivity, It's downside is it's soft and subject to more rapid deterioration. That brings up exotic metals, introduced mostly to extend spark plug life. Iridium and Platinum plugs often have a small tip, and while they have a long lifespan, they have their own issues, one of which is the small tip over heating and leading to a tendency for pre-ignition under very high loads (peak boost at high RPMS for example). When the plugs must operate over a wide temperature range fine tip electrode plugs can sometimes be more problematic to dyno tune. Its for these reasons these seemingly simple and inexpensive plugs work very well.