I was struggling with the B-spec Nascars like many others but after finding the correct settings the races become doable. I used settings that Sirtokealot and DEADLIST used and with some tweaks to them I managed to clear the series with all golds (I used a lvl 18 driver around 60%hot).
Try to experiment with increase pace instead of overtake command if you are having difficulties in overtaking. Increase pace sometimes forces the driver to choose aggressive driving lines and may help with overtaking the opponent earlier...
Here are my settings for the 5 races, remember to change the oil to get an HP edge over the opponents.
Race 1: Superspeedway
downforce 35/50
gears: 380 km/h
lsd: 60/60/15
ride height: 15/-15
springs: 18.5/18.5
dampers front: 8/4
dampers rear: 8/4
anti roll bars: 4/4
camber: 2.0/1.0
toe: default
brakes: 1/0
Not much tactics here...I just spammed increase pace with occasional overtake command until I was first and then it was just a matter of keeping the pace up.
Race 2: Grand Valley
downforce 50/70
gears: 320 km/h
lsd: 60/60/15
ride height: -30/-30
springs: 18.5/18.5
dampers front: 8/4
dampers rear: 8/4
anti roll bars: 4/4
camber: 2.0/1.0
toe: default
brakes: 1/0
Hardest race for me as getting in front was difficult and rear tyres started to lose grip quite fast due to oversteer. High downforce was useful and made overtaking easier for my driver. Try to get to 1st place as soon as possible and then maintain pace around middle bar to avoid wheelspin in the corners.
Race 3: High Speed Ring
downforce 50/70
gears: 350 km/h
lsd: 60/60/15
ride height: -30/-30
springs: 18.5/18.5
dampers front: 8/4
dampers rear: 8/4
anti roll bars: 4/4
camber: 2.0/1.0
toe: default
brakes: 1/0
My driver took the lead on lap 6 after many overtake commands
but after that the race was easy, just keep a steady pace and a win should be in the bag. I also noticed that my driver always understeered hard on the first fast lefthander, dont know if my setup caused it or low driver lvl because the rest of the competition took a much better line through that corner.
Race 4: Laguna Seca
downforce 50/70
gears: 280 km/h
lsd: 60/60/15
ride height: -30/-30
springs: 18.5/18.5
dampers front: 8/4
dampers rear: 8/4
anti roll bars: 4/4
camber: 2.0/1.0
toe: default
brakes: 1/0
Keys here are short gearing and high downforce... the race becomes smooth sailing after you get in front, just remember to keep some pace up
Race 5: Daytona Oval
downforce 35/50
gears: 380 km/h
lsd: 60/60/15
ride height: 15/-15
springs: 18.5/18.5
dampers front: 8/4
dampers rear: 8/4
anti roll bars: 4/4
camber: 2.0/1.0
toe: default
brakes: 1/0
This race was a nightmare before I found good setup for the car. These settings helped Bob to floor it properly and the race should go much easier.