just a heads up on nelson ledges track, here are my comments on driving Nelson.
First, the surface of the track is sucks. There are patches, loose asphalt, potholes, and bumps all over. Grip also changes depending on the part of track you are on. But unless you know the cars limit and are keeping it there it's not that big of a deal.
I am using the corner numbers from this map:
http://www.nelsonledges.com/pdfs/nelsonTrackMap.pdf
T1 - standard high speed corner. Compare it to T1 at Mid Ohio, but narrower.. the fast line is far left down the front straght and make your turn in late. there is a pavement change just before the turn and thats where you want to make your turn in. Just be careful to not blow the exit and go too wide, you will regret it.
T2 - far left (stay in the outside line from T1) to tight inside, this is a faster turn than your mind lets you think.
T3 - fast here and stay close to the inside burm.
T4/T5 (Oak Tree) - becareful through this turn as it consists of different types of pavement and there is a pavement change just before your out of the turn that unsettles the car and can cause a spin if your trying to get on it too hard at the mid to end part of T5. Brake, find the right spot during testing and stick to it. You will feel like you have to brake a lot more than you NEED to. It's an increasing radius corner to 5, so you can carry a ton of speed through it. Brake on the right side of the track and then STAY LEFT, double apex between 4 and 5. There's no point to go all the way out to the right side through here.
T6 - You should be mid-track going into/around T6.
T7/T8/T9 (Carousel) - keep mid-track untill somewhere around the middle end of T7 then cut down to the right side of the track then let the car drift back to the top 3/4 of the track just after T8. pretty much just doing a double apex of T7/T8 so you have a straighter line for T9. T9 you will see the track has a sharp angle on the inside of the turn, this is where you want to hit with your right side of the car then angle to the far left and hit the outside of the track with your left side of the car, there is a pavement change here too that was a good marker point to aim for.
T10 - mid track. drift to the left side before T11.
depending on your exit of T9 this should be about the fastest part of the track, in the stock C5Z i had this was about 130 if i had a good exit and about 126 if i had a bad exit. you should be faster as that car was only 385hp flywheel and on hard street tires.
T11 (the Kink) - this turn can be done alot of ways, i found it best to be far left going into this turn and mid-track out of the turn. there is a huge dip just after the turn that wouldn't bottom out my suspension but did cause bad scraping of the air dams.
T12 - Line up to the right, find your right braking depth and DON'T brake too much! there is a hump in the middle of the brake zone that will cause wheel lock up if your on them too hard and screw you for the turn. brake just before it and let your foot lighten up on the brake as you go over the hump then back on the brakes on the down side. You can carry a ton of speed through here. Brake, turn, and get on the throttle to zip to the braking zone of T13.
T13 - from the apex of T12 look straight across the street into T13, there is a power line pole, aim the car at that pole to set up for T13. This is pretty much a throw away corner. Just don't enter it too fast. There's no need to go to the outside of it at all until you exit on the front straight. The challenge here is making the transition from turning/accelerating from T12 to straight line braking for 13. It needs to be all one smooth move to be fast.
Front straight - STAY LEFT, cars coming in from the pits on the right.
you will need to modify based on your driving and the car but this should get you a good baseline to start from.