I bought the rb6 used. I wasn't aware of the caster inserts and front bulk adjustment. The car had a total of 34 deg (30+4) and narrow rear (RF). The car pushed. I went rf2 rear and 25 deg caster (25+0). Better, but could still use some more steering. So I decided to do 29 deg (25+4) and OH WOW did this car wake up. I had A LOT of steering. It was a HUGE different to where my rear was spinning out where before it never did! I think this car loves 29 deg of caster!