Hmmm spend a ton of $$$ now, or wait for next-gen Z with direct injection?
 

You know it's coming.

Probably not for another four years at least, so I am having fun with this car. DI is nice but not sure it is going to be some that turns the Z into a 450hp/350torque car.

Direct Injection doesn't (really) make HP. It makes MPG...

DI is the wave, baby. Catch the wave. Don't be surprised if they drop DI into the existing Z, could be less than 4 years if that's the case. :stirthepot:

BMW's TT DI inline-six produces 330 lb ft of torque (in the 7 Series), not so far away from your number...throw in the added power, the fuel economy boost, the better emissions and you have incentive for Nissan, especially as the Euros seem hell-bent on stricter and stricter emissions standards.

You crazy.

Two key letters in that BMW...

TT

Once you start talking forced induction...

Show me evidence that the only change is direct injection, and HP/Tq is gained.

Of course DI involves other changes. When you further digitize the fuel delivery process, things like VVEL become even more efficient.

Wiki:

The major advantages of a GDI engine are increased fuel efficiency and high power output. In addition, the cooling effect of the injected fuel and the more evenly dispersed mixtures allow for more aggressive ignition timing curves. Emissions levels can also be more accurately controlled with the GDI system. The cited gains are achieved by the precise control over the amount of fuel and injection timings which are varied according to the load conditions. In addition, there are no throttling losses in some GDI engines, when compared to a conventional fuel injected or carbureted engine, which greatly improves efficiency, and reduces 'pumping losses' in engines without a throttle plate. Engine speed is controlled by the engine control unit/engine management system (EMS), which regulates fuel injection function and ignition timing, instead of having a throttle plate which restricts the incoming air supply. Adding this function to the EMS requires considerable enhancement of its processing and memory, as direct injection plus the engine speed management must have very precise algorithms for good performance and driveability.
The engine management system continually chooses among three combustion modes: ultra lean burn, stoichiometric, and full power output. Each mode is characterized by the air-fuel ratio. The stoichiometric air-fuel ratio for petrol (gasoline) is 14.7:1 by weight, but ultra lean mode can involve ratios as high as 65:1 (or even higher in some engines, for very limited periods). These mixtures are much leaner than in a conventional engine and reduce fuel consumption considerably.

• Ultra lean burn mode is used for light-load running conditions, at constant or reducing road speeds, where no acceleration is required. The fuel is not injected at the intake stroke but rather at the latter stages of the compression stroke, so that the small amount of air-fuel mixture is optimally placed near the spark plug. This stratified charge is surrounded mostly by air which keeps the fuel and the flame away from the cylinder walls for lowest emissions and heat losses. The combustion takes place in a toroidal (donut-shaped) cavity on the piston's surface.<sup class="Template-Fact" title="This claim needs references to reliable sources from March 2009" style="white-space: nowrap;">[citation needed]</sup> This technique enables the use of ultra-lean mixtures impossible with carburetors or conventional fuel injection.
• Stoichiometric mode is used for moderate load conditions. Fuel is injected during the intake stroke, creating a homogenous fuel-air mixture in the cylinder. From the stoichiometric ratio, an optimum burn results in a clean exhaust emission, further cleaned by the catalytic converter.
• Full power mode is used for rapid acceleration and heavy loads (as when climbing a hill). The air-fuel mixture is homogenous and the ratio is slightly richer than stoichiometric, which helps prevent knock (pinging). The fuel is injected during the intake stroke.

Direct injection may also be accompanied by other engine technologies such as variable valve timing (VVT) and tuned/multi path or variable length intake manifolding (VLIM, or VIM). Water injection or (more commonly) exhaust gas recirculation (EGR) may help reduce the high nitrogen oxides (NOx) emissions which can result from burning ultra lean mixtures.

Oh, don't get me wrong...my OP is all about modding a DI engine as opposed to spending the money now. I have a lot of time on my hands, obviously. :p

Haven't there been quite a number of cases of carbon build-up in engines running direct injection?

By the time the Z has direct injection, I'll be ready for a new one. Until then, I get to enjoy driving my sweet car rather than wait for something that may or may not be coming.

I know on my Audi TT with DI there was some concern with heavy deposits and cam follower damage. Im not sure if the Z was to get DI that that means it would have the same prob with the cam but the deposits will probably be there. But there has been no evidence that it is harming the car. I guess you would just need to run some type of cleaner every so often.

Yes there have. Some of the pictures I've seen have not been pretty.... With direct injection the valves no longer get a flow of Gas which serves to keep them clean. The only air you get is mixed with Blow-by and contaminants (oil) from the PCV system which builds up on the valves and stems. I think Toyota employs an additional upstream injector to deal with this, but most don't. Pics of the VW 2.0 FSI and the Porsche Cayenne have been ugly.. Careful what you wish for.

Here's a pic of the newer VW/Audi 2.0 with direct injection (mileage unknown):
http://images40.fotki.com/v1261/phot...iMedium-vi.jpg

Here's a shot of a friend of mine's VW/Audi 1.8T (the engine that preceded the 2.0) with conventional injection, use of good gas, at 125,000 miles..

http://images32.fotki.com/v1106/phot...MG_0600-vi.jpg

Four years is long time to wait, if that's when the next Z is to be released. So many things can and will happen. If it is true that peak oil is at 2012, then who knows which direction vehicles will be heading and whether Nissan even sees fit that they continue the Z in its petrol driven guise. Interesting times are upon us to be sure...

I think we will see more 4 banger turbos now to help on MPG and still keep the power.

There have been audi RS4 drivers dino their cars and log greatly reduced HP over time wiht DI. Requires whole engine clean out. (You may be able to prevent with engine cleaner with fill-ups, but who knows in the long term)?

Who knows when DI will be introduced on the 370...you maybe waiting a while. I don't know much about injection but I do know that the Cayman S got a 20-30 hp bump the year it got DI. Not sure what other changes were made though. Good luck with the wait...or you could just get one now and be doing this :driving:.

Techron, perhaps? I read that Porsche techs use this periodically as well:

BG ISC® Induction System Cleaner™ BG ISC® Induction System Cleaner™ will quickly and safely clean fuel injectors and remove hard, baked-on carbon deposits from intake ports, intake valves and combustion chamber. It is designed to be used with the BG 9210 Inject-A-Flush® Apparatus. For complete cleanup, BG ISC® should be used in conjunction with BG 44K,® Part No. 208, added to the vehicle fuel tank at time of service. BG ISC® will not harm gaskets, seals, hoses or any component in the fuel system if recommended cleaning procedure is followed. Catalytic converter and oxygen sensor safe.

Seems odd though, that manufacturers would be rushing to embrace the technology (see the new Infinity M56) doesn't it?

True, but I doubt those gains were due strictly to them adding DI... I think they made a few other changes too... :)

To OP... hey, if you want a Z now, and can afford it, go for it. No need to wait around for "the next best thing". If you were to do that, you'd never get a car, ever. lol

Fuel additives don't work when the fuel never touches the intake area. With direct injection, fuel is injected directly into the combustion chamber.

Manufacturers are embracing the technology due to the improvements in power, efficiency and mileage.

Most are working on (or have already designed) cleaning set-ups to deal with these problems. If done regularly it might keep things clean, but if not, then head removal and expensive repairs will be the only solution. As I said earlier, be careful what you wish for..

Now about that Stillen supercharger... :icon14:

Well I wish the next Z has a self-carwashing system so it looks clean all the time. Maybe an automatic rim detailer too. Oh, and system to automatically remove my wife's long blonde hair from the back of the passenger seat that always gets stuck and left behind.

Same year that the world will esplode...and most of my loans extend well past...

Screw you banks - hahaha!


Bail yourself out come 2012 - hahaha!

You can also read about DI problems in the Porsche forums….

No, scary times will soon be upon us, for sure,,,

:iagree: :shakes head:

Peak oil was said to be in the 80's...

Given that things die, and oil is created from it, and **** has been dying long before us, there should be plenty of oil. Just a matter of finding it.

That, and there's still ideas such as algae-fuels.

We won't run out of oil...ever.

Of course we won't because there will be other sources of energy to supply our needs.

nissan wont pump out a new z for at least 4 years. it would be a marketing blunder to pump a car out to soon.

no but they can just update the engine after 2 years or so...

DI would be cool but prolly better to get when in 2nd gen when issues have been ironed out...

Seafoam FTW! I bet you'd smoke out an entire city if you attempted to clean that first engine.

The nissan 200ZD

the 2 liter straight 4 cilinder diesel :roflpuke2: