Istanbul Park is one extremely technical challenge, or at least that's what I'm finding. The main problem is the different types of corners, requiring a different direction in car setup for each. There are some constant radius cornes like turns 1 and 4, some blind apex corners, with no accurate braking markers, like turn 3, changing radius off camber turns like turn 2, and don't forget the monster turn in Formula 1, Turn 8.
Turn 8 is a multiple apex behemoth that will make or break your lap. The car spends around 7 to 8 seconds in this turn and getting any one of the apex's wrong will push you wide and off track. Not only is it a difficult corner, it precdes a long down hill run into a tight left hander, a good overtaking opportunity, meaning if you mess up turn 8 and manage to stay on track, you'll get pinched in turn 9 or 10. My attack of Turn 8 involves medium throttle 5th gear, trail braking to keep online, before punching into 6th before the final apex, where I tightly hug the inside. I've found soft spring settings on the car help give maximum cornering grip for this turn.
Turn 8 isn't the only drama, I've long struggled with turn 1. Brake too late and for sure you'll understeer off the track and blow your chances at a the run up the hill through turn 2. I'm braking well before the 100m and getting the car settled with a slower entry speed.
Turn 2 is ok, it's just nail the throttle and try and straightline as much possible before turn 3. Turn 3 apex is blind, so practice is the key here. Miss you're braking point slightly and the off camber corner will push you wide and completely ruin Turn 4. Turn 4, 5, and 6 are pretty standard low speed, 2nd or 3rd gear turns.
Turn 7 is a little trickier than the few before it, with the radius opening up as you charge up the hill toward turn 8. I prefer to hug the inside , but I've seen plenty of drivers take a late entry and move the apex further round. I might give it a try at my next practice session.
I find turns 12, 13, and 14 pretty important for a lap time too. The car is at its fastet as it approaches turn 12, moving at just over 340 kph. 12 sets the car up for 13, where the early application of power can easily result in a spin and usually ruins your turn in and track out of turn 14. If I'm not careful, I often approach 12 too fast and don't clip the inside of the turn, also understeering to the outside and the inside of turn 13 on completely the wrong angle. That ends up effecting my turn in for 14. Pretty much it's a series of undesteering corners if turn 12 gets messy.
Overtaking
Turn 12 is the best overtaking corner as ithe straight from 11 to 12 is the DRS zone, so cars will be carrying maximum speed down here.
Turn 7 is also a good spot for sticking it up the inside, as many cars could understeer here. Just be careful that overtaking on the inside doesn't leave you hung out to dry through turn 8, as if you're on the outside there and have another car on your left, alongside they can just push you wide and off the track into a high speed incident.
Turn 9 is also a decent overtaking opportunity, as is Turn 1, but just beware you track position on turn 1 as it's easy to get pushed off track on the exit of of 1, if you're on the outside, or going through turn 2 if you take on the inside.