Valkyrie

I find my MR-2s Iridium plugs wear out really fast from track days. Do racing plugs actually last longer on the track? So much longer that it's worth paying five times as much?

I understand it's mostly for tuned engines that run hotter, and so you can choose a plug number that prevents knocking, but five times as much is nuts.

Jobro

iTrader: (2)

R7420 do last longer than BUR7EQ in turbo applications. They also have less misfires with high boost tunes.

Valkyrie

Oh, ok. How much longer? Like in terms of track days.

Can you get away with just regapping the plugs for a while, or are they ungappable?

finger lock

iTrader: (6)

I use NGK R6725-105 plugs in my track only, single turbo FD (410 rwhp @ 18.5 PSI). I replace the plugs after ~ 4 race weekends (that's 20 sessions of 25-30 minutes each). High quality plugs give you one less thing to worry about at a track day. IMHO there are places to save money, this is not one of them.

Guy

Valkyrie

My engine is stock though, I just want to know if race plugs lost long enough compared to iridium or platinum plugs to justify the cost in terms of lifespan even when you don't have any knocking or ignition problems.

If I knock the boost up I might have to get them...

The other day I regapped my plugs when they were a little worn down, and it seemed to give me a bit of topend pull back without spending $80 on new plugs.