Link to View Siemens Piezo Injector for the 135i . . .

[atr_hugo]

. . . can be found here. And trade press release here.

[atr_hugo]

And here's Ward's Automotive "10 Best Engine" Writeup.

[atr_hugo]

More Siemens goodies - this time a zipped combo of info called, "Innovative Solutions for Gasoline Engines" (found in a link at the bottom of the page).

[imported_MPower]

What was very interesting was that Ward's writeup where it discusses BMW creating a good sound from the N54. That has always been my gripe about turbocharged engines, they make garbage truck sounds half the time. I think that's why I really like the N54: turbocharged but you wouldnt notice.

[strtfghtr]

Originally Posted by MPower

What was very interesting was that Ward's writeup where it discusses BMW creating a good sound from the N54. That has always been my gripe about turbocharged engines, they make garbage truck sounds half the time. I think that's why I really like the N54: turbocharged but you wouldnt notice.

You get quite a different sound out of direct injected engines (even single turbo charged engines) The note is not at droning and actually sounds almost similar to a diesel at idle. The Mazdaspeed6 has a direct injected turbo 4 and the direct injection does wonders for reducing turbo lag and keeping engine performance up to top notch.

Interesting thing about direct injection (at least in the mazda) is the 2 fuel pumps. One to send fuel from the tank and to prime the pump (about 60 psi) and the high pressure one that sends it to the injectors (about 1700 psi!)

The piezoelectric injection method is an interesting twist (I did some work with piezoelectrics in college) instead of the normal "coil type fuel injector" that works with an electromagnet, the piezoelectric one operates using a special piezoelectric material (see here) that expands when electricity hits it and operates with almost no delay.

[atr_hugo]

Yup - the piezo orifice changes shape even, according to what I read - cool technology!

[335i=:)]

Do you guys know what the max flow rates are for the direct injection? This will give us an idea what's possible with the stock injectors as far as turbo upgrades. My buddy is building a 600whp skyline-gtr. After looking at my turbo setup he says that if you improved the headers and had a full tbe you could go up one size in turbo's without adding any lag, but adding a maximum boost increase of around 20%. This is only if the injectors can flow enough fuel of course.

[strtfghtr]

Originally Posted by 335ito135i

Do you guys know what the max flow rates are for the direct injection? This will give us an idea what's possible with the stock injectors as far as turbo upgrades. My buddy is building a 600whp skyline-gtr. After looking at my turbo setup he says that if you improved the headers and had a full tbe you could go up one size in turbo's without adding any lag, but adding a maximum boost increase of around 20%. This is only if the injectors can flow enough fuel of course.

Though fuel injectors might be an issue I would be more concerned with the tuning aspect as opposed to the physical limits of the injectors. Though my experience is only with the MS6 community no one has run into a problem with the fuel system not being able to provide enough juice yet.

Going with "bigger" turbos is not enough info to tell if it will really affect turbo lag. Different volumetric ratios within a custom turbo itself can add power with minimal lag but you can't go to your local pep boys pick up a giant turbo and bolt it up hoping for it to work without any lag because your buddy with a Skyline says it will. Forced induction is a very tricky thing and as it normally turns out you can't have huge power, with no lag, all across the board. The case of an inline 6 is a little different because even with a little turbo lag you will not notice it since the N/A pat of the inline 6 will take care of the low end (below 3000 RPMS). A bigger turbo conventionally takes longer to spool than a smaller turbo (bigger mass is tougher to get spinning)

[blitzed310]

There is an Awsome book for anyone who wants a good read on how turbo systems work. Its called Maximum Boost by Corky Bell.

[atr_hugo]

+1 on anything written by Corky Bell. I happen to have an old book, "Turbochargers", by Hugh MacInnes in the library (w/ a Gale Banks big block chebby on the cover ; -).

[blitzed310]

Im in the middle of this one: Supercharged! Design, Testing and Installation of Supercharger Systems by Corky Bell as well.

You should check it out.

[ichiban]

These improvements are possible because the precise control and rapid switching of Siemens VDO's piezo actuators are used in conjunction with the newly developed high-pressure pump that delivers the fuel to the rail at a pressure of up to 200 bar.

200 bar ... holy jebus.