1.01 was the accepted correction factor for speed 3's once upon a time. Speed 6 cf is a little higher cf since awd vs fwd.
I never had great results on VD with my speed 3. Most I ever got was 299 whp on e33. freek was telling me I made ~320. It's a guess. Looking at Nishan's dyno videos, my logs look super similar to ones where he made 30+ whp more on his dyno vs my v dyno.
@SharksInSpace dynoed his CS turbo car recently and made more on the dynojet dyno than a
1.09 cf said on VD. so really, it's a guess. use the same road as a baseline and don't read much into the numbers.