Those tires are wrong

Check my replicas from Best Motoring, most lap time done by pro driver like Tsuchiya-san, Nakaya-san etc driving cars with normal tires ( street tires ) can be replicated on comfort tires. F40 Best Motoring lap record = CS tire ( a bit too quick ), Tom's Advox Supra RZ = CM tire. Tuned cars like Top Fuel Civic Zero 1000 ( Turbo with over 370+PS ) = SM tire, Hosaka Tuning Factory R33 and R34 GTR = SM tire.
FEED RX7 Tsukuba Record Holder = SS tire ( bordering close to slick IRL,
ADVAN A050 R Spec G/S ( soft ) Compound that lasts only 3 laps at Tsukuba - less than 3 minutes hot lap ). With the SS, the replica can still be quicker, I easily lap 3 tenths quicker than the best lap in real life at 57.511s at Tsukuba ( driven by Nobuteru Taniguchi )
A stock Nissan GTR with reduced power - using '07 model with similar power to real life to replicate Tsuchiya's lap record in 2009 can be done on CS tire and still can be quicker by a few tenths easily in GT6.
Most R comp semi slick are SM in GT6, and most sports/super cars stock tires are comfort soft or medium. My latest replica, Lexus IS F with replicated weight and power ( GT6 has them all wrong ), heavier and less power, can replicate real life lap record at Tsukuba on CM tire-beaten it during testing by almost half a second. 86GT/FR-S/BRZ uses CH tire to replicate real life stock tires, so generally most sub 200HP cars would be CH tires, some may need CM.
All of my current work in progress FIA GT4 cars replica uses SS tire to replicate real life qualifying times at European GT4 Cup ( silverstone GP used benchmark ) - similar aero, power and weight, gearing, yet most of them can lap a second or 2 quicker than real life on SS tire. Real life GT4 cars uses hard slick racing tires with minimal aero. There are some GT4 replicas that can go 3 seconds quicker at Silverstone GP, might need to drop down to SM tire.
GT6 tires are simply way too varied in grip level - based on cars and needs to be tested by replicating real life lap when comparing to real life, and even so, most of the time still quicker by a few tenths or seconds, then dropping another level might be necessary. I haven't found a single stock supercars that needs sports tires in GT6 to get into similar lap time territory to real life. An F40 replica I made with CS tire can easily lap 2 seconds quicker than best lap record IRL at Suzuka ( stock with factory tires - 2:25s ).