The 3" exhaust was done on a SVT Focus. I can't find it but it was like 145whp stock and 150whp with the 3". TurboTom did it because he was gonna turbo the car anyway and he owns a dyno.
Remember the SVT Focus is a much better flower from the factory than regular Zetecs, so if you were to just slap a 3" on a regular Zetec it might not give you the same gains. IF, you have mediumly modded NA Zetec doing 145+whp, then a 3" could be a benefit, IF you also have a SVT or comperably good header.
2000 Rio Red I4 Cougar
200whp & 210wtq at 9psi
254whp & 276wtq with NX 35shot
WRX TD04 Turbo, Cut Short Shifter, Strut Tower Bar, 17" ZN Wheels, Roush Springs, Starion Intercooler, NX 35 shot, HKS SS BOV, Full 3" exhaust,StreetFlight Chip
| 
