MJones

Not homologated for racing.
DFI Fuel pressure would exceed 75.4 psi (Grand Am)

10 GT3

I would certainly expect this for all the road cars. I think Porsche has already sent the message with the new Turbo. I can't picture this ever being unique to the US versus other markets. If you look at Porsche's history with the US market, they will not bring cars over at all versus putting a different drivetrain in them. The 964 C4 RS, 993 Carrera RS, 993 GT2 and 996.1 GT3 never crossed the Atlantic. The 964 C2 RS, 996.2 GT3, 996 GT2, etc. all use the same drivetrains as those in other markets. The latest specialty car rumor is Porsche is going to release a GT2 RS next year based on the 2010 turbo that will use a variant of the 9A1 engine. Hence, the next time we see a GT3 it will probably have a 9A1 based engine.

MarekN

For better or worse, DFI is coming at one point, if only for emission control purposes. That said, in terms of engine character, it is a big minus.

gasman1

Just a comment on intake valve fouling with DFI. Some
people commented that the 9A1 engines must have some
other causes of intake valve oil fouling (leaky seals, PCV
issues, etc.), since all diesels are DFI and don't seem to
have this problem. The difference here is that the normal
diesel oil change schedule is at a rate at least twice that
for normal Otto cycle engines. I also suspect that most
diesel engines have been refined to to point where intake
port oil pollution/fouling has been minimized. We'll see
how this plays out with the new Porsche DFI engines.

ADias

Do diesels have EGR?

flash1034

Yes

gasman1

Oh yeah, another big difference between diesels
and otto engines is the RPM range. Most diesels
don't ever run above 3,000 RPMs whereas a typical
gasoline engine runs 6,000 plus RPMs. This may
also be a reason for less intake port fouling in most
diesels, I just don't know.

KKJ

The GT3 peak power occurs at about 7,500rpm instead of 6,500rpm for the standard 911. That's not really significantly higher so to prevent use of DFI. - I think the reason is related to tooling costs to change the GT3's engine combined with its relatively much smaller sales volume.