This took me forever to do... but it is possible! Here's what helped me, hopefully it might be of some use to you as well.
1- At the first corner, take a wider line than the AI vans, and make a sharper turn in without braking.
2- On the run down towards the tyres at Chicago, don't brake. Avoid the Ai, straight line as much as possible, drive over some of the (white stripe) cones if you need to.
3- At Chicago don't break unless you are going to run really wide or slam into the AI.
4- As others have said, slipstream the AI towards Hammerhead but pull to the right of them before they brake. Try and make the left turn of Hammerhead with as little braking as possible.
5- This, for me, was the most important - coming out of Hammerhead, do what ever you can to make sure you are slipstreaming someone. It makes a huge difference to your speed for the second part of the lap.
6- After Hammerhead, don't brake at all until the last corner, Gambon.
I must have had literally 100 tries at this, with a best of 9th, before it finally clicked. Then I went 2nd - DQ (cutting Gambon!) - 1st. And I was in first by the Follow-Through on Lap 2.
Don't give up!