So I've got a 99 SH, and I was curious about the HP limit the ATTS unit can take before its rendered useless. I've heard many say 300, but I've seen a few others say it craps out at as low as 240. Also, if you go over the unit's max HP limit, is there an actual mechanical failure and the unit actually "breaks", or is it just that the ATTS unit can't function when the engine's output is about its limit, and will continue functioning normally once the engine's output drops back down to "normal" levels? I'm getting some work done to mine, and I want to add a little power, but only as much as the ATTS unit can take. If I'm gonna make the car lug the ATTS around, I might as well make sure I can use it .