To keep it simple. Car has tbe(catless/muffler delete) intake/intercooler+piping/s2 cams+springs and retainers...i used to run BPR8es...now matter how i gapped them, the car would misfire...now im using bpr7es gapped to .022 and the car doesnt misfire, BUT it doesnt pull as hard anymore, feels sluggish an car is running lean. Could switching to the br7es(non protruding tip) help this at all? Btw im on stock turbo 93 octane. Any help would be hugely appreciated.

 

I use NGK Iridium Spark Plugs Heat Range 8 - BR8EIX. I just have an fp green turbo and bolt ons. Runs amazing. This is what Kevin at Evolution Dynamics recommends...

 

First of all you should run the plug that the car was tuned for. I guess you could try the BR7ES as they would in between the protruding tip BPR8ES and BPR7ES .