If you set the boost cut-off on it will cool your engine.
Try to use it only when you are on the defensive. It's kinda a cheat.
I expect this to be corrected in the same time they re-installed the more stringent 109's EM rules.
280 is what you shld get with a hurri. Start with a shallow dive and coarse the pitch at 12hr (needle full vertical). Retract your rad to 1/4 to 1/3
With a bit of descent rate you shld get 290 easily. Th's a lot deck even if the 109 will still catch you, you'd get time to think how you can manage the unavoidable fight.
The few time I hve tried the Spit I online I did not have any prob keeping a 109 in gun range. But it might hve changed with patches. I am not the best to make a comment here
