My Brisk plugs lasted about 24K before I switched back to NGK Iridium's. The NGK's last a lot longer.

 

As cheap as the NGK iridiums are, I simply replace each year during my maintenance.
Brisk plugs are not worth the price.

 

I am gun shy with most precious metal unless the vendor/manufacturer can justify to me in scientific evidence the much touted "benefits". I bought a cooler set of NGK's OE replacement after 15% pulley installation. Soon I realized the reasons of the quad ground electrodes , and I switched to the cheaper lowly copper plugs circa $1.50 each instead. No negatives noted driving or over-driving on track.

Truth be told, I don't own a gold Rolex nor forged bling wheels that my driving doesn't need.

 

I'm using the BRISK LGS-T plugs in TRACKRAT and, as I understand it, the recommended change interval is something like 10,000 miles. For me, that's a whole lot of track miles so I don't mind changing them, considering what I spend on fuel, tires, registration fees, lodging and food! FWIW, they've given me excellent results.

 

I like how a "performance" vendor present "scientific" proofs of why their fancy pants boutique product is better. On their site they showed the graphs of superior thermal and electrical conductivity of silver they use against the lowly copper.

My immediate question what is the size of their silver electrode compared the no-thrill NGK baseline copper plug? Also at the ungodly combustion temperature and thermal energy, does the fine-hair splitting make any discernible performance difference? Oh, silver is only the entry level of their lineup. There are many more precious metal plugs that they are happy to take your money. I too spend obscene amount of money for each track day, but I value my hard earned money, down to a cent. I do not subscribe to poser performance products.

 

pnw, what brand of spark plugs are you running and how often do you change them? I'm not opposed to trying copper spark plugs, especially if I can get a set for less than $10.

 

Please do a search on this forum. There is a good thread on going back to the basics on NGK spark plugs and what drives these wunderbar multi-electrode spark plugs. I presented my reasons for the switch in my thread, but my thread is so long ...

 

Have to point out with a 17% pulley the engine is seeing more boost and is burning more fuel, generating more heat. The chamber filling is better so pressures are higher than they would be with a stock pulley. All this adds up to the plug having to light a fire under conditions that are even worse than with a stock engine. As a result the plugs can go "off" sooner. So one is faced with shorter plug life. And possibly shorter coil life. And if the engine uses a MAF maybe shorter MAF life too. That's the price one pays for running more air through the engine.

If you don't replace the plugs what else is open to you?

Has the behavior persisted over the span of several tanks of fuel? Could you have gotten a batch of bad/stale gasoline?

How's the engine air filter?

Fuel filter?

Are these due or past due to be changed?

In some cases running a bottle of system fuel cleaner may help. I don't know what's available where you are but I likeTechron. Use it according to directions on the bottle. When the fuel level gets low do a repeat treatment. Drive the car until most all of the 2nd tank of fuel treated with Techron is used up. It is best if after you use this stuff you do an oil/filter service. The Techron can contaminate the oil and you don't want to continue to leave that oil in service.

 

The thread mentioned by pnwR53S about spark plugs is a great primer and a good read,
it is here:
https://www.northamericanmotoring.co...ark-plugs.html

It was reading that thread which convinced me to save my money on pricey plugs and go with NGK BKR7E --- they've performed faultlessly for me on an 06 JCW.

 

With 30k miles on them for sure I'd replace them. We don't use the brisk in our shop as we find them to wear out much faster so I'm kinda surprised you got 30k on them. I'd go back with the JCW platinum plugs as we find them to last the longest and not come loose like some others.
https://www.waymotorworks.com/john-c...gs-by-ngk.html