Hi Gareth, I really can't say as I also have an under tray with diffuser under the front which made a lot of difference.
But, I think that a gnose and spoiler will work much better than what you had before.
Thanks Peter, My goal today was to get a 1:48 something which happened in the first session, then I seemed to go backwards, 1:49.0.
Maybe I was starting to overdrive the car and went slower, don't know?