Which spark plugs is the best for these mods:
Modified VTG, intercooler, ECU reflash, header, muffler. (700HP on pump)

 

I used DENSO IK22 iridium,works awesome.

 

Unless you want to spend a few 100's later like i am doing right now, use the double platinum Denso PK20.
The Iridium is a hotter plug and the tip is too small on it, it last longer but it does not deliver as efficiently. Ask Todd at EVOMS, I think he is the most qualified to answer this question. I currently have a tab of 700 because i used the IK22... just my advise to you. Good luck.

 

I have run the Denso IK22 in my car for almost a year now. We run this plug in tons of high horsepower 996TT as well. For turbocharged cars, you want to run no more then 1 step colder plug. I would not run the same heat range. You can see what plugs fit your car at www.sparkplugs.com.

 

the heat range maybe proper, but when did you take your plugs out last? mine looked like i had them in for 20,000 miles. total miles driven on them less than 400.
the small tip and the Iridium can cause issues, been told this by world class mechanics and tuners. the car will run ok with the IK22's but better in the long run and create better spark with the IP ones.

I mentioned this before in another thread that the tuners at LGM in Dallas, TX removed the IR plugs from my H2 before they said hi to me... it is not a high performance plug, it is a long lasting plug. Hence the breaks that perform better do not last as long.

 

Here is some info on the IK22 -

Iridium is a precious metal that is 6 times harder and 8 times stronger than platinum, it has a 1,200 degree (F) higher melting point than platinum and conducts electricity better. This makes it possible to create the finest wire center electrode ever. Prior till now, spark plug manufacturers have favored platinum for their long life or performance spark plugs due to its high melting point. Also, the technology did not exist to machine and bond iridium on a spark plug electrode (at least in a cost effective manner). Champion spark plugs have produced iridium industrial and aviation spark plugs since the 1960's, but they still sell for over a hundred dollars per plug. Just now is the technology cost effective to use iridium in a spark plug for automotive applications. The strength, hardness and high melting point of iridium makes it very well suited for a fine wire plug. The primary iridium plug manufacturers at this time are Denso with a 0.4mm center electrode, while Champion and NGK have 0.7mm center electrodes. These are the best performance plugs on the market for traditional automotive use and many racing applications. Autolite has introduced an iridium-enhanced plug (the iridium content is too low to call it an iridium plug) we do not consider this in the same class as Denso, NGK or Champion.

 

Thank you for the info.
I still am going with the Denso PK20's.

 

I will gladly give the PK20 a try.