Do I need J&S if I have Hondata 3b and MSD DIS-6?

 

You don't need it, but it's an extremely nice safety net. I'm a Stage 4 user and I used to play with my car a lot. The J&S was an awesome feedback tool to let me know when I was pushing it too much.

When I parted out my Civic Si to sell it, I only kept 2 aftermarket parts: the Hondata and the J&S Safeguard.

Sonny