Vassili95, since the Zetec is being phased out in early summer 2004 with the introduction of the 2005MY, there really isn't anything left to engineer on the Zetec. I was involved with the tail end of Zetec engineering, but it should be noted that SVT has its own separate engineering staff. Also, I don't have vast tuning experience, and I assume that's what you're inquiring about.
Eggyolk, I don't have many secrets to share. The PZEV-specific content in the ENGINE doesn't hurt performance in any way. That content doesn't really involve items that you can modify anyway. For the development of the Duratec 23 engine, engineering didn't leave anything "in reserve" that could be pulled out their back pocket by tweaking or tuning if they wanted a few more HP. To gain more HP, you would have to actually modify powertrain hardware. Hence, some of this was done for the 2005MY hardware to get even more power out of the smaller displacement Duratec engines coming for 2005MY. But don't get too excited - there wasn't much left to do (like I said above) - the modifications to intake/exhaust likely result in only a few HP benefit.
A few more tidbits on intake/exhaust hardware:
-The intake manifold has two internal valves, a charge motion control valve (that activates around 3000 RPM I'm guessing) and a variable induction or communication valve between plenum volumes (that activates around 4500 RPM I'm guessing). Even if you could tweak the engine calibration in the powertrain control module (PCM) for these two valves, I would not advise it because those are optimized for flow (which means optimized for torque and power) and you'd only be hurting not helping.
-The thermactor air or secondary air system dumps fresh air into the exhaust manifold for faster lightoff of the catalyst. It only operates at startup.
Soffiler, great questions.
1) Not positive on my answer, so I'll ask a buddy to see that he agrees before I respond to that one. Give me a week or two.
2) The engine block doesn't warm up at a rate that is inconsistent with other state-of-the-art engines. If it's faster than the Zetec, it's not by much. I'm surprised you guys think it's exceeding fast on the PZEV. The Duratec I4 engines use Visteon's Black Oak PCM. The previous engines used the older EEC-V PCM. The instrument cluster for one PCM is not compatible with the other, so the cluster is all new for the Duratec I4's, even though it may look the same. Perhaps the temp gauge is calibrated differently, but any difference should only be slight. As for emissions - warmer engine block means little to emissions - it's all about the catalyst, which is fully lit before the engine block is fully warm (see my thermactor air comment above).
3) Main reason air filter is not serviceable is like you guessed - to ensure good seal for PZEV evap emissions requirements. Not only is it difficult (but not impossible) to make a filter element seal well enough for PZEV evap, but it's even more difficult to guarantee that careless do-it-yourselfers and oil change shops re-assemble the air filter box correctly. If too many vehicles were found to be serviced and/or re-assembled incorrectly, CARB/EPA could find a way to make Ford liable for that, which could lead to a recall. As concerned as Ford is about recalls, and as many recalls as Focus had for 2000MY, they couldn't flirt with that risk. It's also difficult (and more expensive) to service an air cleaner that is not in the engine compartment. But locating the air cleaner and inlet in the lower fenderwell is not without its benefits. Hot intake air results in lower power, especially on hot days at low speeds (think stop and go driving in Palm Springs or Vegas in the summer). The lower fenderwell has much cooler air than the engine compartment on the hot days. Speaking of cool air, what do you guys think the reason is for the duct situated just behind the LHS fog lamp?
4) No significant hardware changes were made between 2003 and 2004 for the PZEV. I wasn't aware of the Ford website saying 148/152. I believe the final numbers were 145/149 (and Ford doesn't exaggerate even 1 HP or ft-lb like some Japenese makers). Still, 149 ft-lbs in a Focus?!? Is that not awesome? The ST next year will have even more!
Hopefully that's enough for you guys to chew on for a while.
Quick question for the group - how do you feel about the NVH (Noise, Vibration, Harshness) of the PZEV with the Duratec I4 engine/powertrain? Engineering put a lot of effort into it. If any of you have driven both the PZEV and Zetec on the freeway, you'll probably agree that the difference is night and day. I know some of you tuners like more exhaust note, but vibration at highway speeds can't be as desirable.
]
