Thewespaul is right. I don't know if anyone has taken my suggestion but the guys at PDD really have gone through a lot of this stuff on Cummins and have videos and numbers available on Youtube. I've not talked with them but I bet they would be willing to discuss options with you if you gave them a call or sent them an email. I'm not in anyway remotely tied to their business I just like the way they go about tuning and testing various setups. They do have stuff available for the IDI on their website as well. Let me know how this works out for you as I was thinking of building a compound system as well someday.