520 Chain Conversion

Im new to the gen 4 but have owned a gen 2 for several years and only use on track. Just been on my first track event on the gen 4 and noticed the chain varies from tight to pretty loose which is odd and not as I would expect. I want to convert to 520 anyway so will see if a new chain and sprockets help. Question is what are people finding a good combination of sprocket sizes for track? 17:45 standard and I was thinking of just dropping to 16:45 but as I’ve had limited track usage I thought I would see what people are running.

For track only 16/43 or 16/44 depending on the circuit.

Thanks for the response. According to gearingcommander.com changing from 17:45 to 16:43 makes a real minimal difference to each gear RPM and top speed - top speed gear 1 is 89 vs 87.7 and gear 6 is 186.9 vs 184.1.

I've found 16/45 is plenty, not many tracks you can top out in 6th with a 17fr

I think I heard that 15/43 is used in BSB for UK tracks.
I'm running 16/46 at the moment, which is fun, did fine at Almeria, didn't top out. I have a 44 for tracks like Portimao where I want it to be longer and flatter driving off the corner

Thanks 16:46 looks better on gearingcommander although not sure how accurate it is now as it has the gen 4 specs as having 118 link chain.