Around 40. And braking doesn't affect nor cause it. Same tires on the back an no shake from the back
AS I previously mentioned, the tyres are just magnifying the issue and making it WAKE up if you will more than stock sized tyres.
You had mentioned that you can MAKE this happen with stock tyres, this indicates to me it is not the tyres that are the issue.
Clearly there is something not right in your front end and until that is addressed PART by PART....if that means a complete diss assembly of all the parts and a good solid physical inspection...then that's what it needs! What about a cracked part? Be it Track Bar mount brackets, or bushing eyes? What about a cracked Knuckle or spring mount?
So much to thoroughly inspect. Take it to a reputable shop, have them fully inspect / check everything and deal with it that way. If you yourself at this point have not had success in finding the culprit, I strongly encourage you for your safety and that of others to have this professionally taken care of. Yes that will cost you $$$ but how much does dead cost or worse...maimed and crippled....dead never costs as much as maimed and crippled for life...How much is a good nights sleep worth????
... maybe I'm wrong...but I suspect others here would mostly agree....
JM2CW ...