Car makes a grinding noise when you take off and falls flat on it's face what could it be?

More details please. What is grinding? What do you mean falls flat? Engine dies? Pops out of gear?

I can't tell if it's the engine grinding or the tranny...it'll barely even pull itself in any gear but it don't start making a grinding noise until you're going about 10-15 mph but that is also pedal held all the way to the floor and that is as fast as it will go

I agree with Tom. The total loss of power sounds a bit like a plugged catalytic converter. The engine will make a weird sound when that happens although I wouldn't think of it as a grinding noise, but it might be. But do get it checked first by a mechanic, it could be a number of other things too and attempting to drive it anywhere is probably making it worse.

I'm not driving it right now but I bought it as is at an auction and it ran and drove just fine there but when I got ready to take it off the lot it would barely even move and was making a grinding noise...so I'm stuck with I was just trying to get some idea's at what it could be

Torque converter may be shot.

Ok thanks for the help