Witch kind of Spitfire and 109 ? I suggest to consult the IL2 Compare Software to compare performance. Here is an example.
Bt 109 F4 vs Spitfire Mk V M45 12lbs
IL2 Compare 4.11m (almost the same FM's of 4.12.2m and 4.13.3m)
https://1drv.ms/u/s!AutwPlOKpNiE7wnZhn1BYJ0xED5J
This video can help i think.
A track 109 vs Spit (Ace)
https://1drv.ms/u/s!AutwPlOKpNiE7won0xQzGxuux9pp