Hello everyone, I am hoping that by starting this thread I might inspire you, or others to embark on the journey of figuring out the beloved 4.0L engine with me. The past 6 years I?ve spend a massive amount of my time and money on everything from XJs, ZJs, WJs and even a few TJs, all of them having the bulletproof 4.0L engine.

The 4.0L is a well built and naturally balanced engine, that doesn?t exactly make higher horsepower and torque numbers. I recently over the last 3 years was working on a home brew turbo setup on a 4.0 and stumbled upon HPTuners. I bought my dongle and got to work. I?ve started getting fairly knowledgeable with making changes but I am still very far behind. I was hoping that I could find some people that may have a little more documentation than I have already sourced up.

So far I?ve managed to find the ECU operating strategy and what sort of factors are actually in play with these computers, and with that I would like if someone would be willing to work with me and help me develop a full blown guide and explanation sheet for those that may come after us. Someone has to do the legwork for this all to be easily accessible for everyone. I?m willing to start that process.

I have tons of tune files and documents from Mopar that I?d be willing to share with anyone who may want to help, just shoot me a DM, or post here. I?ll add all my tune files and documentation below as well.