The IS-F Yamaha/Toyota V8 runs extremely hot under track conditions. We recommend upgrading to colder plugs. We tested these Brisk Silver plugs, and we highly recommend them for our normally aspirated tuned applications. This product includes 8 plugs.
Brisk Silvers Premium Racing Spark Plugs LGS have unique multi ground electrode design and a silver core giving an outstanding performance in igniting overreach mixture associated with tuned performance engines.
As the arcing occurs around the 360 degrees and is not mixture dependent a bigger gap is used at lower voltage levels thus increasing greatly an ignition surface area.
Silver metal is the single best material for a spark plugs core electrode, as it can dissipate heat fast, resulting in overall lower spark plug temperature and more powerful spark. The stronger the spark the faster and better the flame front, couple this to the multi earth electrode design and the dependents on a homogeneous mixture needed to be found around specific point, as it is the case on single earth, hook electrode. is not required.
Brisk recommends changing these spark plugs every 50,000 miles.
These plug work very well with all Lexus V8 normally aspirated models (ISF, RCF, GSF, IS500, and LC500). We highly recommend them with our tunes.