New VAG DI/PI engine

[NateDN10]

Audi is coming out with a new version of their 2.0L turbo I4. What I thought most interesting is that they're using Toyota's idea where port injection is used at part load and direct injection is used at idle and full load. They say PI is actually better at mixing with air at part load, so using it reduces soot & CO2 production. What's not mentioned is that it means they won't have to deal with crud building up on intake valves anymore.

Maybe this is the way forward for DI?

 

[JHZR2]

Dont these systems only have one or a few of the standard, "old tech" injectors?

If so, seems reasonable to me, as the added cost isnt much and yo still get the benefits of DI.

If it is two parallel injection systems, that seems excessive.

A hybrid seems sensible, if it is simple and small enough. I doubt the DI is only on at idle and full load though...

 

[demarpaint]

Too bad they don't can DI altogether and improve what worked for decades before DI came to the gas engine.

I can hope, can't I?

 

[Nick R]

Originally Posted By: demarpaint
Too bad they don't can DI altogether and improve what worked for decades before DI came to the gas engine.

I can hope, can't I?


Maybe we should just go back to throttle body injection and carbs. They worked for over a century, didn't they? :|

 

[demarpaint]

Originally Posted By: Nick R
Originally Posted By: demarpaint
Too bad they don't can DI altogether and improve what worked for decades before DI came to the gas engine.

I can hope, can't I?


Maybe we should just go back to throttle body injection and carbs. They worked for over a century, didn't they? :|



Yea Ok. I guess I should have spelled it out better for people like you. I guess the word decades threw you.

Sorry. What is wrong with the fuel injection systems used in some of the 2012 and 2013 vehicles that are not DI?

 

[Nick R]

Originally Posted By: demarpaint
Originally Posted By: Nick R
Originally Posted By: demarpaint
Too bad they don't can DI altogether and improve what worked for decades before DI came to the gas engine.

I can hope, can't I?


Maybe we should just go back to throttle body injection and carbs. They worked for over a century, didn't they? :|



Yea Ok. I guess I should have spelled it out better for people like you. I guess the word decades threw you.

Sorry. What is wrong with the fuel injection systems used in some of the 2012 and 2013 vehicles that are not DI?


And I ask again, what is wrong with carbeurators? There are clear advantages of DI over Port injection. Stronger low end torque, better fuel efficiency, allows for higher compression ratios (increasing power and efficiency). There are downsides,
but nothing that can't be fixed, with VVT, different EGR and PCV designs. Not to mention, working out the kinks in DI technology now will open the door to HCCI in the future. IE gasoline engines that work like a diesel- compression ignition.

The moment we stop innovating and striving to improve and advance, is the moment that we are doomed to stagnation and failure.

 

[Sayjac]

I suppose after Audi's early adopter fiasco with DI they felt the need to add something extra to inspire confidence in their latest generation.

I'm still waiting to see the proof of predicted horror stories of the latest generation non hybrid DI. BG's been the only one to cast some doubt, but they too have vested interest in an outcome.

 

[Quattro Pete]

Originally Posted By: Nick R
The moment we stop innovating and striving to improve and advance, is the moment that we are doomed to stagnation and failure.

True.

What is wrong is that some companies have made guinea pigs out of consumers, thus turning off many early adopters. Alas, it's hard to test long term effects in a rush to quickly bring innovation to the market place. Of course, some engine makers did not have the problems that others did.

 

[demarpaint]

Originally Posted By: Nick R
Originally Posted By: demarpaint
Originally Posted By: Nick R
Originally Posted By: demarpaint
Too bad they don't can DI altogether and improve what worked for decades before DI came to the gas engine.

I can hope, can't I?


Maybe we should just go back to throttle body injection and carbs. They worked for over a century, didn't they? :|



Yea Ok. I guess I should have spelled it out better for people like you. I guess the word decades threw you.

Sorry. What is wrong with the fuel injection systems used in some of the 2012 and 2013 vehicles that are not DI?


And I ask again, what is wrong with carbeurators? There are clear advantages of DI over Port injection. Stronger low end torque, better fuel efficiency, allows for higher compression ratios (increasing power and efficiency). There are downsides,
but nothing that can't be fixed, with VVT, different EGR and PCV designs. Not to mention, working out the kinks in DI technology now will open the door to HCCI in the future. IE gasoline engines that work like a diesel- compression ignition.

The moment we stop innovating and striving to improve and advance, is the moment that we are doomed to stagnation and failure.


Carbs had trouble with EPA standards, required adjustment, and weren't as good as fuel injection.

As far as DI when you see you're having problems with the technology like Audi did instead of sinking billions into a fix why not change the technology or improve upon what was working just before it?

Evolution of technology and innovations are great, sometimes you might have to scrap an idea and start over again at the drawing board. Many great ideas were scrapped after they came to be, it happens.

Originally Posted By: Quattro Pete


What is wrong is that some companies have made guinea pigs out of consumers, thus turning off many early adopters. Alas, it's hard to test long term effects in a rush to quickly bring innovation to the market place. Of course, some engine makers did not have the problems that others did.


True, but is seems to be the norm with the auto industry. Which is why buying into the first year or two of a new technology is not a good idea.

 

[dparm]

The 3.0TFSI (supercharged 3.0L V6 in the S4, S5, A6, A7, etc) uses a totally redesigned PCV system, among other things. Carbon buildup is virtually zero now.

I've seen photos of the motors with 30k+ on the clock and there's no buildup. Compared to how the 4.2 FSI (RS4, Q7, etc) looked with only 10-12k, I'd say they've fixed the problem.

 

[demarpaint]

Originally Posted By: dparm
The 3.0TFSI (supercharged 3.0L V6 in the S4, S5, A6, A7, etc) uses a totally redesigned PCV system, among other things. Carbon buildup is virtually zero now.

I've seen photos of the motors with 30k+ on the clock and there's no buildup. Compared to how the 4.2 FSI (RS4, Q7, etc) looked with only 10-12k, I'd say they've fixed the problem.


Sounds like a step in the right direction, too bad for the people who bought in too early.

 

[bruno]

DI came to gas engines in the '40s in aircraft and in the '50s in cars . It's been around for quite a while .

 

[demarpaint]

Originally Posted By: bruno
DI came to gas engines in the '40s in aircraft and in the '50s in cars . It's been around for quite a while .


Then they should have it right wouldn't you think?

 

[rjundi]

I found it interestig Nissan pointed out in literature they avoided Direct Injection but got great efficiency in their 2013 Nissan Altima redesign. It manages 27MPG city/38 highway in a reasonable sized and comfortable car. Not a small penalty box.

 

[demarpaint]

Originally Posted By: rjundi
I found it interestig Nissan pointed out in literature they avoided Direct Injection but got great efficiency in their 2013 Nissan Altima redesign. It manages 27MPG city/38 highway in a reasonable sized and comfortable car. Not a small penalty box.


This is what I was referring too. Advances can be made with improving what has been working well. DI works great in diesel engines, in gas engines they've had issues, which is why companies like Nissan and others are holding off.

 

[Sayjac]

Quote:
I found it interestig Nissan pointed out in literature they avoided Direct Injection but got great efficiency in their 2013 Nissan Altima redesign. It manages 27MPG city/38 highway in a reasonable sized and comfortable car. Not a small penalty box.

While perhaps interesting, I wouldn't put much thought into any real meaning as regards their non use of DI. Afterall, they are the same company that couldn't manufacture a reliable catalytic system with their new at the time 2.5L engine in 02-03, that left owners twisting in the wind when the engines failed. Based on that, DI may just be over their heads.

 

[Quattro Pete]

Originally Posted By: rjundi
I found it interestig Nissan pointed out in literature they avoided Direct Injection but got great efficiency in their 2013 Nissan Altima redesign. It manages 27MPG city/38 highway in a reasonable sized and comfortable car. Not a small penalty box.

Sadly they forgot to include manual trans as an option. Otherwise, it does look like a great car, inside and out. I must say, I'm impressed.

 

[mechtech2]

"And I ask again, what is wrong with carbeurators? There are clear advantages of DI over Port injection."

Yes, but only sometimes in certain circumstances. It is not always so.
That is why dual systems are offered, . Note the sound reasoning why in the OPs post.
When cruising or at light throttle, high vacuum exists, and fuel is vaporized very well by port type injectors.
DI systems can take advantage of higher compression ratios and VVT in certain circumstances, but not all. DI improvements are NOT just from DI, but left handedly from high comp ratios and different tuning. Some give credit exclusively to the DI injectors.

Not sure why CARBURETORS are mentioned here.

 

[SteveSRT8]

No offense intended here guys, but if Porsche is using DI I am a believer. That company does R & D for many other big names in both cars and motorcycles, I seriously doubt that DI will have any real issues after a couple more years.

WE are the proving ground. Every DI vehicle is being carefully tracked for warranty frequency, etc., and the data developed will be combined with industrial espionage (buy a competitors car!) to solve all the issues.

 

[mechtech2]

Steve -
Porsche used air cooled engines when virtually all others used water cooled.
Did that make you a believer in air cooled engines, then?

The workable DI solution is to use upstream injectors, like Ford and others researched. Thus, cleaner intake valves and the best of both worlds for engine efficiency.
But my goodness... What a complicated system, and heavily regulated. All sorts of stuff to go wrong and add huge costs.