Adrian,
I have two cars with the 01X. They have only test miles on them, and those are not hard miles, but I am confident with them. They are both behind 450HP aluminum small blocks. Before making the selection, I considered the way that rating is arrived at. It factors three things: friction coefficient (stickiness of the tire), contact patch (square inches of tire footprint), and downforce (weight on the tire). In other words you could probably run a thousand horsepower through that transaxle to a bicycle tire with no weight on it, but you may only be able to run one hundred through it if it is connected to a pair of huge and sticky top fuel drag slicks with a wing over them generating thousands of pounds of downforce. Looking at realistic numbers for the factors involved with these cars, I cannot see why they would not handle that horsepower.
