[Phil Stubbs]

I've been having some lagging issues in my last few races, which has been confirmed by other users. It's fairly slow motion, not the sudden jumping around you see sometimes. As an example, going down a straight I'll move forward and backwards relative to other cars, over 1 or 2 seconds, then go back the other way
I've reset my router, download speeds are 13 Mb, upload 1.0 Mb, ISP ping time is consistently sub 20ms, ping in Assetto Corsa SRS app is anywhere from 30-111. I don't think this should be an issue.
PC is i5 4690k, R9 290 xfire, running AMD BFBC2Game profile, frame rates are at 100fps+
Anyone of a technical mind have any advice?
Cheers
Phil