This is what I was using last night. It is not specifically developed for Spa, but after giving it a run and a few small tweaks its coping pretty well. It is still a work in progress, so don't expect miracles. Its very sure-footed and stable, just a little heavy getting through the slower turns, especially T1.
Its been round the block this car, so fully run in and capable of pushing out 892bhp.
It's a 2010 Dale Earnhardt Jr Impala. I managed a 2:14.282", but capable of so much more with a little refinement.
NASCAR 570pp RH Spa-Francorchamps
Specification
Max Power __________ 775 bhp
Weight _____________ 1664 kg
Performance _________ 570 PP
Tyres ____________ Race Hard
Odometer ___________ 982km
Aero ________________ 50, 62
Ballast _____________ 99 @ 50
Power Level __________ 86.9%
Transmission
1st __________________ 2.538
2nd __________________ 1.711
3rd __________________ 1.258
4th __________________ 0.983
Final _________________ 3.850
Max Sp. ________________ 350
LSD _______________ 10, 10, 8
Suspension
Ride Height __________ -25, -27
Springs ___________ 17.7, 16.0
Extension ______________ 9, 7
Compression ____________ 2, 2
Anti-roll Bars ____________ 7, 3
Wheel Alignment
Camber _____________ 0.4, 0.2
Toe ______________ 0.08, 0.08
(P.S. - tune links updated in OP.)