I’m not a Porsche Expert, but I Play one on the Internet

March 12, 2008

By no means am I a mechanical expert when it comes to my Porsche (or anyone else’s for that matter). I’m learning more each day and consider myself pretty well informed, but if you’re looking for true technical experts, you need to seek out guys like Bruce Anderson and Peter Zimmerman.

Online Porsche Forums

As a self-confessed non-expert, I sometimes find some subjects and topics a bit intimidating, especially ones that others might consider to be more basic.

I’ve mentioned before, that I’m a member of most of the popular on-line Porsche forums (Rennlist, Pcars, 6speedonline, etc.) and they all have lively technical discussion forums. However, at times, due to the lack of emotion and ability to express sarcasm in a forum post the responses can seem, hmm, how do I put this? They aren’t hostile; I’m positive that’s not the intent. Let’s call the answers… short. Yeah, that works.

So in the spirit of this post, I’d like to open this up to everyone that has a question to ask, but for whatever reason, they just haven’t done so yet. What basic questions about Porsche do you want answered? What are the things that you have felt too shy to ask elsewhere? Ask me here and if I don’t know the answer, I’ll research it and find one for you (I’m not saying it will be 100% spot on, but it should at least be entertaining). Besides, where else can you get your own personal Porsche research assistant for absolutely free?

Don’t be shy. You can submit your question in the form of a comment to this post. Or, if you think your question is just way too embarrassingly basic, then use the contact form here and your question will come directly to me with no one else any the wiser.

Some Basic Porsche Questions

Here are a few questions we’ll be covering in the coming weeks based on suggestions we’ve already received:

What are Carrera chain tensioners and do I need them?
What’s the difference between and air-cooled Porsche and a water cooled Porsche? (I’m surprised at how many times this question has been asked).
What other type of products does Porsche produce?
I like to invest, where can I buy Porsche stock?

You get the idea from the list above. Nothing is taboo and nothing is too basic. If we can answer it we will; each question will get a response.

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Written by 993C4S · Filed Under Advice

Comments

3 Responses to “I’m not a Porsche Expert, but I Play one on the Internet”

C on March 24th, 2008 10:04 pm

I bought a 2002 996 with an x51 engine. The original engine was replaced around 22k to 24k miles (not sure exactly when) .Can you give me a more detailed difference between this engine vs the regular 996 engine?

I understand with the x51 comes PSE (exhaust) and ECU flashed. Is this true? Kindly elaborate if possible. Also, what do ECU and DME stand for? Are they different and if they are, what’s the difference?

Thanks in advance for whatever advice / comment you have.
993C4S on March 25th, 2008 8:22 pm

@C/Carlos, thanks for the question. As I said in my email to you, “be careful what you wish for.” You’re question is a tough one, but interesting.

You’re the first to post as a comment! Most have emailed directly. I’ll get to work on this for you and it will be the subject of a post later in the week or early next week.

Thanks,

993C4S
dedes on April 3rd, 2008 9:34 pm

996 with a X51engine driving feeling has more torque, powerful and much faster than standard 996 engine.

ECU & DME answers:

In automotive electronics, an electronic control unit (ECU), also called a control unit or control module, is an embedded system that controls one or more of the electrical subsystems in a vehicle. Some modern cars have up to 70 ECUs, including:

* Engine Control Unit
o also called Powertrain Control Module (PCM)
* Transmission Control Unit - TCU
* Telephone Control Unit - TCU
* Man Machine Interface - MMI
* Door Control unit
* Seat Control Unit
* Climate Control Unit
* speed control unit

Digital Motor Electronics (DME) is a microprocessor based system that controls the ignition, fuel injection, oxygen sensor, and numerous ancillary functions of an automobile. The DME provides raw data to an on-board computer that uses an alphanumeric display to provide you with information such as the average fuel consumption, the driving distance available with the fuel in the tank, average speed, outside temperature, etc.

In the automotive industry, DME is often referred to as the Engine Control Unit (ECU), under the heading of Electronic Engine Management Systems. BMW also uses the term Digital Diesel Electronics (DDE) for diesel engine models instead of DME.

DME operates by continually monitoring such factors as engine temperature, speed, intake airflow, exhaust gas composition, and even altitude. DME can fine-tune the engine hundreds of times a second to provide maximum performance and efficiency. DME has a fail-safe program in the event of certain electrical faults. Current DME versions also have on-board diagnostics (OBD).

The two main tasks DME performs are (1) the injecting of the proper amount of fuel and (2) providing a spark at the correct time. In order for this to happen, the system requires information about the engine’s current state. DME can track dozens of different sensors, however, every system needs to know three basic things:

1. How much air is coming into the engine.
2. The position of the throttle.
3. How fast the engine is running.

Using the information about how much air is flowing through the engine and how fast it’s turning, DME uses a fuel map to determine how long each injector should stay open each cycle to inject the right amount of fuel. During part-throttle operation, the injector pulse-width is also modified by the readings from the oxygen sensor, a device that sits in the exhaust collector and determines how much oxygen is left over in the exhaust. Each cylinder is constantly adjusted to maximum operating efficiency under virtually all conditions.

In the event of an electrical fault, DME can reconfigure itself to bypass the problem and it can diagnose itself for quick and efficient trouble-shooting.