okay, another thing to look at is the drivers skill, and the wheel size, the gear ratios, aerodynamics, all of those you must take into consideration when you think of 1/4 mile times, the actual question was why isnt there any 10sec sr powered 240s in the US, and i have to likely anwsers, either the sr owners dont care to run 10 sec 1/4 miles, you just havnt heard about any yet, and there could possibly be none in the US...hell it might not even be the car, maybe you could drive someones sr powered car and get into the 10 sec range, in my opinion the only real way to see which one is better is to have a race, one KA, one SR, with the car being the same, and have one driver, say he runs 5 ,1/4s with the ka, and 5 with the sr, and average the times and see which is faster, or atleast thats how i look at it...hell i could be wrong, i really dont care tho...