Hi everyone Ive been driving my 1.6 diy pnp powered turbo miata for about 2 months now with no problems. But on the wayhome tonight I put my foot down and it seemed to hold back Alittle under full boost. I have my boost protection turned off so that wasn't it. But it also misfired and made a bang as if the fuel had ignited in the exhaust.

I have never had this problem until tonight. I'm guessing at the plugs not been good enough but that's a total guess. They are quite new but I'm using ngk 6 series o believe. The car is runing 240 bhp in the engine at approximate 18 psi. However i couldnt verify if it was actually reaching that tonight as it seemed to be around 14psi ish.

As I said never had this problem before and I haven't changed anything or accessed the ecu etc to even try and change anything. I'm using a Nissan 200sx t28, rx7 550cc injectors, brain diy pnp, standard internals etc

 

You need to upgrade the plugs to a 7 series - ie BKR7E-11 - and gap them down to 0.8mm or less.

 

I will have a look tomorrow as I have never even set the gaps on the plugs. So I suppose I was expecting this. I wonder why it took so long to start misfiring.