I had my cossie set up a few weeks back to 382bhp. It recently started breaking down under load, so I changed the plugs for some denso iridium ones. Dont break down anymore but it feels like its pulling another car with it!! completely lost its raw pull. Anyone else had somthing similar happen with changing plugs?

By the way I gapped them to 0.7mm

 

hi mate


are they IK31's ? if so you should have no problems


marco

 

i tried one of the idenso plugs..can find out the number...but they were killer plugs.been lasting a long time.and no problems what so ever

 

IK27 what we used as IK31 we'd usually stick in +400bhp.
Fitted loads of 27's to similar specs with no problem, but this one has us baffled.
I wouldn't have thought the differnce in heat range would have caused such a problem, only under load.........