I am pretty familiar with Cape Ring so I thought I would just throw a few tricks for those who are not, and now it ended up as a whole walkthrough. Enjoy, ignore, use or abuse, and share your own
Turn 1: Do not go too wide on exit, stay on tarmac at least. You want to get over to the left side soon, so you can follow the inside rumble strip in turn 2 (right-hander). The next is crucial for a good sector 1: Brake and turn sharp left where the rumble strip ends (go a slight bit wide at the turn-in), coast for a moment so the car gets balanced, and be patient. Imagine a straight line through the apexes of turn 3 and 4. Do not power on before you can hit that line. Doing so also allows you to do the right-left (turn 4-5) as straight as possible, with as little turning as possible. There is a surprising amount of tenths in hitting this right.
Turn 6-7, the left-right uphill: Brake just before the 50m sign. Use *some* throttle to keep the rear in check, if you release the throttle completely the rear wheels engine-brake and the rear goes sideways. Back to full throttle while turning right. Do not hit the inside curb of turn 6, but in turn 7 right wheels on the grass is fine. Around 150 kmh over the crest.
Turn 8: Simple U-turn. Stay to the right before brake and turn-in, so you can take a late apex, get more exit speed.
Turn 9-11 (big right hander followed by left-right and a short straight): Full throttle all the way. Follow inside line around the big circle. Focus on turn 11: You need a low entry angle if you are to keep full throttle (and not throw yourself into the left wall). Basically ignore turn 10. Just run over it, on the grass as much as allowed, as needed and as possible.
Turn 12-14 (slight right, sharp left and uphill, U-turn into short straight): Start braking slightly in turn 12. Maybe go on the grass if you can keep the car straight. Brake hard between turn 12-13 and make sure you have a good turn in before powering on, easy to go wide here. Keep the balance and try to stay at the middle of the road on the uphill. Going along the inside is too slow, going wide is slower. You want to end up in good balance and parallel to the left curb before turn 14; do not come screeching across from the right at last moment. Turn 14 should be late-apex'ed. Brake just before the curb ends, turn and trail-brake or coast, then full power. The banking in this turn means you can easily get a little powersliding, that is good to get the car turned and aligned to the straight. So just full power. And stay on tarmac!
Turn 15-18 (the "istanbul" complex): Do it as one big turn with one apex at the middle. Full power with slight turning until first apex, coast and slight braking past apex 2, then accelerate out past apex 3 and 4.
Turn 19-20 (chikane leading out): A little tricky, you need to throw the car over both curbs. Imagine a straight line going through both apexes. Attack the first curb following this straight line, maybe slow down a bit shortly before. Release throttle, brake and turn left *just* before you hit the first curb, coast over the second, it automatically turns the car left if you already have the weight to the right. Immediately back on the power as soon as you can avoid going into the grass.
Turn 21-23 (up to the big loop): 21 a simple U-turn, but again go wide before turn-in and late apex it to get carry much speed out to the straights. 22-23 just full throttle. 22 maybe over the grass but not 23.
Turn 24 (the big loop): Full throttle all the way. Touch the right kerb to help turning into it. My entry speed is around 215-220kmh, falling to around 205 for a while, ends around 199. The trick to keep the rear behind you instead of going sideways and crashing. It is a balancing act. You might be able to hold the wheel still, but you risk that it suddenly snaps. I constantly move the wheel a little left and a little right, to keep the balance and direction and avoid surprises. Towards the end you need to turn harder to avoid going wide into the barriers. Try not to cross the right curb at exit.
Turn 24-25 (left-right uphill): Close to left apex, then close to right side and right apex, maybe right front wheel in the grass to aid in turn 25. No need to brake anywhere. And if you start turn-24 turn-in a little early you can get the rear in a slight slide where you do not even need to lift off. Early turn-in for turn-25 as well. The car must run straight before you reach crest. If you go over the crest while still turning, you are thrown off, or at least forced to lift off. On full power you can hardly avoid going towards the right, but you need to regain balance and go to the left as soon as possible for the next turn.
Turn 26-28 (double left and the final turn): Full throttle until first apex (at least if you managed to get the right entry line), brake slightly but not too much. But most importantly, get close to the second left apex, and brake early, getting the car in balance and parallel to the left line. Start turn-in around where the left curb ends, and go as close to the wall as you dare, full throttle from as early as possible. It is ok to go over the curbs of the side road on the left (though I think the blue tarmac is not track so only with the left wheels). Exit speed at the second curb 160+ kmh, 205-6 kmh at the line.