best lense for drag racing

as an avid fan of drag racing i'm getting another lense .. just picked-up a 70-200 2.8 (non is ---- dam) ... i have a 70-300 w/is . why would i want a 300 mm when i allready have a 70-300??? now the next choice is between a 300mm f4.o w/is or 100-400 w/is .. i just can't make up my mind .. any advice please?????? thanks for looking and your help ..... promod

Best lens for drag racing? Why the fastest one you have of course!!!

What's wrong with your 70-300 with IS..?

Well, first I'd sell the 70-300. I'd probably go for the 100-400. Use it from a distance when the light is good. As the light starts to fail, move in with the 70-200.

100-400 is great but sucks if its not sunny out...i have it and the 70-200 and its a nice combo for drag racing...

would you not use the 100 - 400 is at around 1/125, and pan?

I like a fast shutter on the starting line for drag racing, and about 1/60" -1/100" for the panning about 1/2 way down the track...

I had great success with my 55-250mm so I would think what you have would be perfect. Depending on your seats, I don't see why you would need 400mm... I was shooting mainly 70-150mm... so the 70-200mm f/2.8 might be perfect.

Also, I wouldn't use IS for the panning shots anyways...

Good luck!