Reading my race notes for the GTWC, it seems I tried the CLK-GTR with no success (tho I did get her handling acceptably) and 200 A-Specc'd it with the McLaren F1-GTR. Annoyingly, my race notes don't detail what set-up I ended up with in the Merc, just that I got her handling acceptably. My apologies. I can look into it if you wish, tho' on recent tuning performance it might take me a long while to get on the case (most embarassed I am at my lack of GT productivity over the past year).
The car of choice for 200 A-Speccing the series is the Black Beauty 787B but I have never been one for following the 'easy' path (especially not when that path all too often in GT is a Japanese car)

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In lieu of concrete set-up details for the Mercedes, here are my series notes:
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Professional Hall
Gran Turismo World Championship
Championship Race Series
Any Tyres
Any car
International A Licence Required
Prize Money: 25,500cr/race, 250,000cr/series
Prize Car: Ford GT LM Race Car Spec II 04 (Value 212,499cr)
Tokyo R246 (10 laps) (Grid)
Twin Ring Motegi Super Speedway (21 Laps) (Rolling)
Hong Kong (18 laps) (Rolling)
Seoul Central Reverse (19 laps) (Rolling)
El Capitan (ll laps) (Grid)
New York (15 laps) (Rolling)
Opera Paris Reverse (18 laps) (Rolling)
Suzuka (9 Laps) (Grid)
Grand Valley Speedway Reverse (11 laps) (Grid)
Circuit de la Sarthe I (4 laps) (Rolling)
I have only done this series once before. My notes show I used a Minolta and B-Specced a lot of the races after qualifying. The opposition seems formidable and this is just the sort of racing I dont like (very high powered race cars).
Try it in the CLK-GTR and see what happens.
Grid: Jaguar XJR-9 Race Car 88, Mazda 787B Race Car 91, Sauber Mercedes C9 Race Car 89, Playstation Pescarolo Courage C60 race Car 04, Minolta Toyota 88C-V Race Car 89
At Tokyo R246, poled by 2 seconds with 126.979. Terrible race that I aborted on lap 2 after I got barged out of the way and then spun the car. My reflexes just arent up to this kind of frantic driving on a grainy pictured TV. The grid was 186 A-Spec, not that that matters.
Try again versus grid of:
Playstation Pescarolo Courage C60 race Car 04, Mazda 787B Race Car 91, Nissan R92CP Race Car 92, Audi R8 Race Car 01, Minolta Toyota 88C-V Race Car 89
A-Spec would have been 174 but the CLK-GTR has serious rear tyre wear issues and I span out on near-reds on lap 8. Pitted and switched tyres to R3/R2 which seems to work okay but finished last. The car has bad handling characteristics that do not synchronise with my style. It has snap oversteer braking into corners and has mid-corner to exit understeer.
Moved on to Super Speedway and got utterly panned. The CLK-GTR snap oversteers and then slides whenever you brake for a corner. Awful. Spend a couple of nights spannering it and got it to handle better but it is still not a winner Im sad to say.
Switch to the BWM McLaren F1 GTR Race Car 97.
Grid: Minolta Toyota 88C-V Race Car 89, Gillet Vertigo Race Car 04, Nissan R92CP Race Car 92, Nissan R89C Race Car 89, AMG Mercedes CLK-GTR Race Car 98
Running on R3s with power cranked up with a Turbo 3 to 723HP, managed to take pole from the R92CP. Ill run a One Pit Strategy rather than a zero pit and stick with my R3 tyres. The start will be tricky as I reckon Ill spool up the rears with so much power. I thought I was in trouble when 200 A-Spec came up but I managed to hold the lead off the line. Lost it during lap 6 as the R92 just kept getting faster and faster (I did too but he was doing better 

. BL 126.427. I pitted and switched to R4s. Came out in 6th place but on lap 7 everyone pitted it seems, except the Vertigo, which held up the R92 when he came out of the pits and allowed me to catch up and pass him. BL on R4s was 125.249 MOV = 3.502 seconds.
Twin Ring Motegi Super Speedway
I drive this track very poorly indeed, which is a bit embarassing as it only has two corners, The AI seem to go fast here too so Im expecting trouble. I get it. The best I can qualify is 4th. The three Mega-Nippon cars are just too fast for me. Even running R4a and raising the rear ride height I cant take the corners as fast as them. Run the race and expect to swear a lot. The big three pit early and I briefly think I have a chance but I persist too long on my reddening tyres and spin out. I havent saved the series so Ill have to swallow the loss and move on I think. Or abandon the series and start again
thatll be tomorrow tho (got to allow time for my blood to cool ROFL).
Did the restart. Took R246 again with about the same performance and tactics. This time at Motegi, try for a different strategy. Run on Super Hards and dont pit. That didnt work. Finished a lap down in 4th. I expected them to pit twice and they didnt. I watched the AI run on the replay and they were taking the bend into the S/F straight at 160mph compared to my 140mph and were 10mph faster than me on maximum speed. No wonder I cant keep up. I recognise that I will never be able to beat them here and move on.
Hong Kong
Pole with 114.837 (up 2 seconds). I think if I want to pit only once here Id better use a harder compound on the rear. Run R3/R2. Got punted into the hairpin on lap one and never recovered. Perhaps need to try a higher TCS here to counteract the spin-cycle factor.
Restarted the PS2, spannered the suspension and drivetrain and got my qualifying time into the 112s.
Brakes: 5/5
Springs: 13.8/13.8
Ride: 70/70
Damper B: 5/4
Damper R: 9/8
Camber 2.0/1.0
Stabs: 5/4
Gears: Tranny Trick then Final 3.000
Downforce: 38/47
LSD: 10/40/40
BL 112.069 MOV 7.550 seconds.
Seoul Central Reverse
Will this be a nightmare? Qualify with 151.977, up a mere 0.145 seconds. I smell defeat in the air here. Ive saved at the start of this so I can try again if it all goes horribly wrong. BL 51.902 MOV Huge. Essentially, the gap to second place stayed between 2 and 4 seconds for quite a few laps. I realised that I probably wouldnt have to pit if I took it steady and was amazed that all the AI did pit. That made for an easy win.
El Capitan
Oh dear! The car handles terribly here. The bumps and dips drive her crazy and she swaps ends at every provocation. Tried everything I could to make it work and everything failed. Dampers, Springs, Ride Height, Stabalisers
nothing made it handle once you were going at a competitive pace. Did the insane thing of stiffening the rear stabs and softening the front whilst increasing rear ride height. Better not fabulous but itll do. Clicked up the rear downforce a touch too. Didnt note the time but I made pole by a couple of seconds. Didnt work in the race; span out twice on lap two trying to catch the AI after they charged away from the start.
Try a different set-up strategy, running R3s all round. Poled with 132.562 (up 7.294 seconds) with no drama except for some unanticipated understeer.
Brakes: 5/5
Springs: 13.8/13.8
Ride: 70/70
Damper B: 4/3
Damper R: 6/8
Camber 2.0/1.0
Stabs: 6/6
ASM 10/10
TCS 5
Gears: Tranny Trick then Final 3.000
Downforce: 38/53
LSD: 10/40/20
Try R3/R2s and was 8 tenths slower and a lot less friendly to drive. Im not seeing the ASM activate but it must be doing something as shes still lots better than before. Running with +16 Weight Balance gets 131.221, altho shes still a bit hairy in the corners. Try the race with ASM on (Im not too proud to admit it helps (tho it does hurt to say it!)). BL 129.718 after a pit stop on lap 6 to switch tyres to R3/R3. MOV was monumental. Ill never scorn ASM again as I got overtaken and spun-out by the Big Three on Turn 1 and was in last place by quite a way once I got my self turned in the right direction again. Before the end of the lap I was in P2 again and P1 shortly after

. Ive a feeling the TCS had a lot to do with it as it was flickering an awful lot here.
Anyhow, 200 A-Spec in the bag.
New York
Running with set-up A, poled with 127.047 (up 2.824 seconds). The back end is very skittish so try a few amendments. TCS up to 5, rear downforce maxed at 53, weight balance +16. Didnt help much as it made her a touch pendulum-like. Keep the higher TCS and try reducing the LSD D to 20. Commit to the race and pray. That nearly proved very costly. The low LSD D didnt have the effect I anticipated and made her a swap-ends monster at Madison Square Gardens. Tried to go the distance on one set of tyres to make it up. Took the lead when the AI pitted but realised I wasnt going to make it switched to R4s for the last three laps and got BL 124.326 MOV 4.558 seconds.
Opera Paris Reverse
Put the LSD D back to 40 before I forget. Running Set A the car is terrible again. It snap oversteers when braking for corners or if you turn too sharply and understeers on the way out. I got 122.628 for second on the grid (0.6 seconds down). Try Set B. Took pole with a cautious 120.413 (up 1.419 seconds). The car still reacts badly to all the ruts and bumps but its much better. Raise the Ride Height to 80mm and see of it helps. Couldnt hold off the Big Three and got punted into the barriers. Restart. Poled with 117.287 (up 4.322 seconds). BL 114.401 MOV Monumental (the R92CP pitted twice!).
Suzuka
Try Set A for qualifying. Nope nightmare oversteer and loss of traction booting it out of the corners. Tweak rear downforce back to maximum. Drop LSD D to 30, Rear Brakes to 4 and fit R3s to rear. Poled with a dreadful 153.024 (had two off-track excursions) (up 0.6 seconds). The problem now is understeer. Drop the rears back to R2s and drop LSD A to 30. No good still get slidey back end and understeer in the same corner. Most frustrating. Run Set B. Still bad as you can feel the ASM gathering up the car as it wants to flip around and slide. Poled with 151.487 (up 2.128 seconds). Run the race and pray I dont crash. Well that didnt help
punted off at Turn 1. Restart. Ran Set A with the ASM turned on. Poled 149.063 (up 5.233 seconds). Tried to go the distance on one set of tyres; didnt work as the rear end lifted into the Spoon and I just ran straight off the track with steering and brakes utterly ignored. Try her on R4s with a lap 5 pit. Poled 147.622 (up 5.993 seconds). Oops, only 187 A-Spec. Leave it for now as my blood is at boiling point.
Back to the attack. Qualify on R3s using Set A altered to increase rear downforce to 50 and the LSD to 10/30/30. Poled with 149.675 (up 3.940 seconds). Bl 147.417 MOV 5.757 seconds after a last lap excursion and scare! The cars handling is very strange indeed and I cant make up my mind whats causing its large variability in steering and braking response.
Grand Valley Speedway Reverse
Using the same set-up as above, poled with 140.037 (up 9.819 seconds). Im planning a lap 6 pit, lets see if the rear tyres last that long. BL 139.595 MOV 3.399 seconds. Had a bad scare on lap 6 as the AI bashed me off into the sand on the last corner and left me in last place and having to pit. Fought my way back to the front and took the win.
Circuit de la Sarthe I
My nemesis, in a car I know will be a nightmare here, with its predilection for braking oversteer and high speed corner understeer. Obviously Im going to need to pit will R3s make it on the rear? Poled with 332.686 by only 0.490 seconds. My gearbox is too short but Im thinking that maybe the tyres will last all the way. Reduce Final Drive to 2.760 and rear brakes to 3. Raise the Ride height 5mm to 75. Here we go, get ready for a wild ride ... yep, punted off at the second corner across Blackpool Beach and into the barriers (the AI are MUCH faster). Reset. Adjust Final Drive down to 2.670. Poled with 330.299 (up 2.156 seconds) but the cars handling is scary (and the AI speed down the back straights is also nasty, tho I seem to have them beat down the Mulsanne). BL 330.867 MOV monumental. The Big Three all pitted at the end of lap 3 and left me free and clear. Had a couple of twitchy moments on the final corners with nearly-red tyres at the end of the race but she held together and conquered.
The McLaren F1 GTR clearly needs a session in the Spannering Club to try and correct her handling peculiarities but she is obviously fast enough for the job, even against the best of the AI opposition. The only place she failed was Super Speedway and that may be more due to the driver than the car.
Anyhow, 200 A-Spec except for the aforementioned Super Speedway race.
Reran that race a number of times before finally submitting and using the Black 787B (R2 tyres and 171KG Ballast gave 200 A-Spec). I only won tho because the R92CP seemed to have an incident and lose it, thus allowing me to get in front of him and finally hold the lead once the Minolta pitted out of my way. Watching the replay, he ran smack into the end of the pit-lane wall and then proceeded to muck up attempts to pit on the subsequent lap or so ROFL. My BL was 030.660 with TRT of 1101.897 MOV 13 seconds over the R92CP, despite all his disasters mid-race.