Riz

Are the Cayman engines getting direct injection for 2008? I just drove the base Cayman for past couple of days while my GT3 was in for service. I absolutely loved the handling. The power was adequate for NJ roads. I don't even need the S. I'd rather get the base car with 17" wheels, no PASM, as a daily driver. Will wait for 08 model if there are going to be changes.

Edgy01

The Carreras are getting FI in the MY09 cars. Suspect all the boxer 6s will see DFI in MY09, including the Boxsters and Caymans.

pcar964

Where did you hear this, is it confirmed? Very interesting.

V2Rocket

If Carreras don't get FI till 09 what do they have now?

JEC_31

Solex carbs, of course. Many ppl upgrade to Webers tho.







Actually they all have F.I. as in "fuel injection", but the subect of the thread is D.F.I., "direct fuel injection". Google or wiki will help you.

Edgy01

Typo...meant to read DFI.

Of course they all have fuel injection,--since the early 1970s!

opus

Just how much extra hp and torque will the engine with DFI give over the same size engine without DFI?

V2Rocket

I was wondering lol...I read they had mechanical fuel injection in like 1971.

JEC_31

The main thrust of this technology is large gains towards theoretical perfection in the realm of putting perfectly atomized fuel-air mixture in the combustion chamber at exactly the right time. It was developed mostly in diesels, with the goal of raising efficiency and mileage.

Of course, it follows that if you raise the effiency you can either operate at the same old power level with great savings in fuel cost, or you can spend the same old amount in fuel and reap more power. I know what I would choose!

But I don't have any data to present. 10% more power? 15%? 25%? 0.02%? My educated guess is that the level of power upgrades would really depend on the goals of the manufacturer. Porsche has commited publicly to go green, and soon - but knowing them they'll engineer both mileage AND power gains.

99firehawk

look at the cayennes. 40 hp diffrenc 06-08

Dubai911

15% more power is what happened on the Cayennes. These should appear on 2008 models, which is why I am gonna wait and see.

JFScheck

You forget they also increased the size of the V8 engines in the Cayennes - so this is not a good examble to use...

JEC_31

OK, the Cayenne data is not a straight comparison. I suspected as much, because knowing the continous-improvement engineering mindset of Porsche (as we all know how important not only the model year but sometimes the early/late model year is when ordering parts!) they probably changed about 900 things on that truck's powerplant, many of which may or may not be part of the DFI.

I'm going to do some searching and maybe posting questions on the Eng-Tips forum.

What we need to know is the difference between two motors that are (fairly) identical except for EFI on one and DFI on other.

BRB...

JEC_31

Lots of sifting through sand to glean nuggets if any, as that forum often generates multiple discussions per thread and they don't have the proper quoting technology. Also some members are fond of copy-pasting lengthy press releases unedited for data content.

Best thread I found, dating from 2001 to 2004:

http://www.eng-tips.com/viewthread.cfm?qid=13450

Read it if you have free time, but it has no substantial data referencing power/economy increases - what data is mentioned is dismissed by others as hype. it's probably all outdated too.

~~~~~~~~~~~~~~~`

Googlin found these tidbits:

http://www.porsche.com/kbase.aspx?po...edfi&lang=none

http://jalopnik.com/cars/news/sporto...ion-224144.php

http://ogst.ifp.fr/index.php?option=...agne_v58n1.pdf


Well, back to work.

epbrown01

The big change for the new N52 engines in BMWs currently is DFI, and they've seen 15% power increases (225 to 255 bhp) using the same displacement (3.0 liters).