270 CDi remap..

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Even more strange that you quote a thread about a petrol car being remapped in a diesel car thread.

Without proper testing the reports are anecdotal. Many people will report improvements after a due to changes in driving style, or taking the OBD readout as gospel.


I quoted that because people were saying you will not see mpg gains with a remap and yes his engine wasnt removed and ran on a bench in a lab..

Have a read, it explains a little more.
Remaps for diesel engines


As said before not too bothered who believes what, i know what results i have seen on my own cars..
 
I quoted that because people were saying you will not see mpg gains with a remap

The MPG he see on the dash will be wrong because the car does not know how much fuel is being used since he had it remapped.

He might think he is getting more MPG though and that will make him very happy. A win win as you said earlier! :thumb:

Russ
 
Other than increasing fueling and then maximum boost, there isn't anything else on a diesel.

For accuracy, there *is* more..
The only parameters affected by a remap are:

  1. Requested boost pressure.
  2. Injection duration.
  3. Injection timing.
The changing of all of the component maps within the ECU (on the VAG cars, there's a smoke map, there are temperature maps, somewhere about 15-20 separate maps) and each map processing gives an offset to each of the three above parameters, and the end result is what is acted on by the fuel injector control and boost pressure control systems.



It's the timing that can make a big difference. Earlier injection means more injection window available to fuel, as long as the injected fuel combusts correctly (cylinder pressure and temperature high enough to allow combustion). Early injection with a short injection window, e.g. at idle, sounds harsher and more metallic. Another effect of earlier injection is a change in the output gas consitiuents, with a change in the amount of NOx produced. Some exhaust gas quality meters will pick up on this.


I've had a mechanically-injected AHU-engined Passat, and it was possible to directly modify the injection timing through the VAG-COM software. It was interesting to hear the quality of the engine ignition sounds change as I ran the engine test where the injection start point was changed.


Higher boost pressure gives higher peak cylinder pressures and temperatures, and this alone will give better thermal efficiency at the risk of closer to the mechanical limits of the engine. Remapping on a turbodiesel can certainly improve real-world fuel economy through higher boost pressures only.
 
Let's update that topic.
I own a CLK 270 CDI for almost 2 years now. 193k km, 40k since.
Next week, I will decat' it (both precat and main cat) drive around 2 000 km to see the difference, and afterwards I will remap the engine.

I let you know the different steps and enhancement in power and consumption !
 

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