Stock run 163rwkw
Plemun spacer +7rwkw
Pop charger/ Z tube +7rwkw
Light wieght pulleys and extrators +14rwkw
Y pipe yet to dyno guessing +4rwkw
I have a grounding kit too but i don't think it gives more power but on the box it did say up to 5hp more power (i don't think so)
These are my gains and everyone gets different results. But it looks like you get about 7kw for every $300 mod. not including install costs.
You can pay more or lees for these items. but i payed about $300 for each one. Y pipe was the cheapest and pulleys the most.
Best run 191rwkw
Hoping to break 200 with next mod. But in no rush
P.S this topic has been covered before. do a search.