ECU P4120534 Super Stock / Pro Stock / Nascar

I have that on the wall in the shop. I have tested it. The damn thing works and only retards 1 degree in 10,000 RPM.

I think they were worried about hear building up in the unit during street driving. I'm not going to say to use it on the street, but if I didn't need a two step, or a start retard or other timing retards, I'd use it on the street.

I've boxes by other manufacturers on the street that said not to.

Again, I'm not advising you to do it, I'm just saying I would. But I ignore very good warnings all the time so I'm used to failure.