Im boosting around 5psi currently and planning to go upto 8psi useing DSM 450cc injectors and VAFC hack. the problem im getting is initially (until yesterday) i was using Split fire platinum plugs for my setup. my car use to run rich but whenever i use to check my plugs they were always in best condition. they alwys were almost golden in color (means buring was good) but for some testing reason i changed mine to the stock ones which are NGKs bkr6e something. now on the same tunning and fuel maps. my car started to blow black smoke and started to bog as if too much fuel in the combustion chamber.

I took the setting down to -37 and still there was a little bit of black smoke. changed the ignition timing by hand (which means i dont know what is it at the moment) but same responce. ill get it tunned thogh but i have a couple of questions to be answered.

1. Which spark plugs would do a good job! my stock NGKs? or the splitfire platinums?? (im unable to find colder plugs here till now, will get iridiums when ill have money)
2. What should be the idle idnition timing considering that im planning to run 8psi of boost on B16a JDM version???

please answer. thanks in adv