Do you even know what they do for your dads engine?
Did you recently raise the boost? because you seem to say its been tuned and running strong for a long time. therefor deductive reasoning tells me your dads car still has the stock diverter valves installed, since your now asking for the most basic parts any vag car usually needs when the boost is raised. (the oem dv’s tear apart from higher boost pressure, they should be the first thing you replace when mods start)
so this tells me:
A: your dads s4 is still stock tuned, thus running around on stock dv’s without issue.
B: you think the 007’s will give you the WOOOOPSHHHHH sounds that drop panties.
C: since I am the only one here giving you meaning full advice, tells me you should never post here again, since it will get you nowhere.
kind regards
KK