The Piezo effect: Can you say 170hp TDI?!

[Googo]

Actually, piezo actuation is not a new third method of Diesel fuel injection beside CR and PD. It is merely a method of actuation that uses special crystals that can expand or "actuate" under a piezoelectric excitation as opposed to electromagnetic solenoids. The technology can be applied equally to PD and CR, i.e. you can have piezo CR or you can have piezo PD. The newest VAG V6 and V8 TDIs are common-rail with piezo-actuated injectors, while the abovesubject 170 HP 4-cyl have piezo-actuated unit injectors.

With either scheme you still need a means of some sort to raise the fuel pressure. Piezo technology does not do away with the plunger pump in PD systems or the rotary-piston pump used in CR systems. It is merely a system of controling the injection event by controlling needle lift or fuel pressure in the injector by actuating a spill-valve. It's chief benefit over solenoid actuation is that it can actuate one or more orders of magnitude quicker for better and more rapid control of the injection event. That's all. There's nothing magic about it.

Piezoelectrics can be used to inject the fuel, but as far as how much pressure it can produce, I am not sure. Example - most inkjet printers today use piezoelectric materials compress and squeeze out a drop of ink. But from reading, the new fuel injectors just change the actuation mechanism from a solenoid to a piezoelectric.

 

[ensanity]

so is it feasible to retrofit our cars with something along this line? I wouldnt mind having a few more ponies!

 

[Ross UK]

Am I missing something over US emissions law? I was under the impression that European engines would fly through US emissions laws. Surely if a Chevy 5.7 gas engine can pass emissions laws, a VW TDI would have no problems. Most US cars imported to the UK have a very hard time passing the emissions test.

Is it to do with your diesel fuel? I know we have low sulfur fuel in the UK and zero sulphur in other parts of Europe. Here in the UK, most VW diesel owners pay less road tax as the engines are so clean.

 

[bhtooefr]

First, we've got "low sulfur diesel", which (IIRC) is 500ppm maximum.

Second, our emissions standards are DIFFERENT from yours. Yours emphasize low greenhouse gases. Ours emphasize low particulates and NOx. While diesel has very low greenhouse gases, it's got high NOx and (for LSD) high particulates.

Finally, that Chevy 5.7 gasser is sitting in an SUV or pickup truck that doesn't even have to meet the same emissions standards.

 

[Ross UK]

First, we've got "low sulfur diesel", which (IIRC) is 500ppm maximum.

Second, our emissions standards are DIFFERENT from yours. Yours emphasize low greenhouse gases. Ours emphasize low particulates and NOx. While diesel has very low greenhouse gases, it's got high NOx and (for LSD) high particulates.

Finally, that Chevy 5.7 gasser is sitting in an SUV or pickup truck that doesn't even have to meet the same emissions standards.

No need to take offence chief, I wasn't suggesting your fuel or laws are inferior to ours. Thats why I asked a question and didn't come on here shouting the odds. I find it odd to say the least that you have different emissions regs for an SUV/Pickup compared to a normal car.

 

[bhtooefr]

I wasn't taking offense I was saying that our laws and fuel were inferior to yours, though

Anyway, there's a few reasons why SUVs and pickups get breaks. First, people like farmers and construction workers actually need the power, and you just can't get the power without the emissions. (And the car manufacturers classify the SUVs as trucks.) Second, the Big Oil Companies want to get more money. What better way than to make gas guzzlers look attractive?

Something scary to think about: One of the H3s scores a 6 on emissions, IIRC. The Jetta TDI scores a 1. The SULEV II version of the Prius scores a 9.5. 0 is the worst possible. 10 is the best.

 

[Ross UK]

I wasn't taking offense I was saying that our laws and fuel were inferior to yours, though

Anyway, there's a few reasons why SUVs and pickups get breaks. First, people like farmers and construction workers actually need the power, and you just can't get the power without the emissions. (And the car manufacturers classify the SUVs as trucks.) Second, the Big Oil Companies want to get more money. What better way than to make gas guzzlers look attractive?

Something scary to think about: One of the H3s scores a 6 on emissions, IIRC. The Jetta TDI scores a 1. The SULEV II version of the Prius scores a 9.5. 0 is the worst possible. 10 is the best.

Apologies for the misunderstanding. So it would seem that the US system of emissions testing is more weighted toward particulate and carcenogenic output than CO and CO2 emissions.

 

[nicklockard]

Apologies for the misunderstanding. So it would seem that the US system of emissions testing is more weighted toward particulate and carcinogenic output than CO and CO2 emissions.

The trend is toward California-style emissions regulation (CARB) which heavily weights visible forms of emissions (visible particulates and NOx gasses.)

I think it has a lot to do with Southern California's tourist-oriented business climate.

It's incredibly narrow minded and myopic. If we adopted European style emissions models, diesel sales would naturally increase, and overall consumption of distillates would be pushed down compared to the gasser-dominated market we now have.

Moreover, on this side of the pond, we lack regulatory stability, as member TdiMeister has said many times. That makes it harder for manufacturers to provide us with advanced technology, simply because they spend so much of the R & D budget striving to meet the latest emissions goals.

 

[heavystarch]

Yeahhh... ain't rediculous great? One day, such technology will be readily available even in the USA. I hope.

Well something along those lines of luxury diesel sedan is availble but in a Mercedes platform. The E320 CDI has 205HP and 369lbs/torque. Chipping this car will bump it up to 235Hp and 420lbs/torque which is pretty nice.

I've driven it for over an hour during a test drive and it was very impressive - the automatic transmission wasn't my favorite as it was a little slushy at times and probably needed more time to reprogram itself for my style of driving.

Still a good sign that some higher power diesels are making their way into sedans here. I know Jeep has a diesel in their Liberty, and the Toureg has that big nasty V10 diesel...wish they would have done a V6 diesel instead...ahhh so many things VWOA needs to do better.

 

[tdisedanman]

Well something along those lines of luxury diesel sedan is availble but in a Mercedes platform. The E320 CDI has 205HP and 369lbs/torque. Chipping this car will bump it up to 235Hp and 420lbs/torque which is pretty nice.

I've driven it for over an hour during a test drive and it was very impressive - the automatic transmission wasn't my favorite as it was a little slushy at times and probably needed more time to reprogram itself for my style of driving.

Still a good sign that some higher power diesels are making their way into sedans here. I know Jeep has a diesel in their Liberty, and the Toureg has that big nasty V10 diesel...wish they would have done a V6 diesel instead...ahhh so many things VWOA needs to do better.

Hmmm, the way VW decontented diesels all these years, then, when the 05.5 first came out, had nice options included only to make some not available and put others in different packages makes me wonder how serious they are about increasing sales in this market. A V6 diesel toureg would probably have hit a home run. But, with fuel on the rise over the last year 1.5 years, why they brought a V10 here in the states is beyond me. I think they are trying to hard to be different rather than providing a nice mainstream vehicle that Americans want and CAN AFFORD.

 

[BeetleGo]

Piezo injection will almost certainly become the mainstream solution in modern passenger diesels, regardless if it's in a $50k or something much more affordable, if only because it will play an important role cleaning up emissions. The cool thing about this technology is that it meters fuel so precisely that pretty much ALL of it is burnt up before anything can escape out the back end! When you combine piezo injection with particle filters and ULSD (or bio!) emissions become REALLY clean. The fact that this technology squeezes out significantly MORE power at the same time is what makes this so exciting.

It gives me a reason to hold on to my current car until this set up becomes available later in the decade.

~BG

 

[zanakas]

How does Piezo injection work? I mean...in an oscillating crystal, it is grand, but how does it relate to the fuel supply of my car?

I had a set of mica tweeters, once, and they didn't last too very long.

 

[BeetleGo]

How it works...

http://www.boschautoparts.co.uk/pcDies11.asp?c=2&d=1

Use any search engine and type "How does piezo injection work?" There's plenty of good stuff out there on them.

By the time we start seeing Piezo injection in Golfs/Jettas/Civics/Carollas, they'll have been on the market a few years so you'll be able to make some assessment of their reliability from the reputation they'll have by then, I would think.

I suppose that's one up-side to the North American market, with our getting all the new stuff LAST!

 

[Deansel]

A V6 diesel toureg would probably have hit a home run. But, with fuel on the rise over the last year 1.5 years, why they brought a V10 here in the states is beyond me. I think they are trying to hard to be different rather than providing a nice mainstream vehicle that Americans want and CAN AFFORD.

I'm thinking that VW and/or VWOA noticed that almost all vehicle advertising in the USA is focused on power and performance, not on economy and efficiency. By the time our fuel prices went up - post Katrina - it was too late. Where things go from here is really up to the market demand, government regs, etc. but, I can understand that decision from a pre-Katrina point of view.