Thats some good info, we've tried a couple designs so far, just came up with a new one that seems to be doing better. Once we get it running, I'll post some pictures or something. We got a Pulse Width Modulator from here:
Bakatronics that really helped boost production.
According to the John Goodwin guy, his tank lasts for 700 miles-- there is a picture of it in the actual magazine- it looks like a large carbon fiber tank. When I talked to him on the phone, he says that his box fools the computer and injects less diesel fuel and releases the hydrogen.