I thought it might help to clarify one thing here first. I have had a lot of problems with nails here where my office is since they are always building new buildings or renovating old ones. Here is some clarification:
1) Is the nail in the field of the tire? (i.e. more than 2" from the side wall of the tire). If yes, continue.
2) If it is in the field of the tire, did it do into a tread block, or into a seam. If into a tread block continue.
3) If pull the nail out, does it leak air (do this with the wheel off the car and in a the place you are going to fix it). If No, then you may not need a patch, if yes, continue.
4) If you find that you need a patch, using a radial patch from the inside of the tire is the only good way to do that. You must allow sufficient drying and setup time for the patch before putting the tire back on the wheel and the wheel back on the car.
I have sucessfully patched Pirelli P-Zeros a few times with no problems up to 120mph. If you push it to more than that, you are aksing for trouble. Depending on the specific thermal properties of your tire, heat build up can cause these to leak again sometime from a leak in the patch. The patch transfers heat differently and thus can create some problems at very high speeds.
If your nail is too close to the sidewall, you may find that you have damaged the cords in the tire and the tire may come apart at speed. That is not safe for you or anyone next to or behind you.
If your nail is in the seam between tread blocks, and the diameter of the nail is sufficient, it can actually draw the patch material up through the hole and cause a failure.
Be careful out there.