Wednesday, Dec 21, 2011 at 03:12
Thank you to all for your contributions to this discussion.
Having done a bit of research, this is my take on the subject, although I'm sure others will have a different understanding.
Expectation - If you want more power that delivers more torque through the drive train you can achieve it by fitting a ‘chip’ which delivers more fuel to the engine. If you want to consistently use the increased power available you should expect to use more fuel. If you want more power to be available when required but the key issue for you is fuel economy, there are other considerations.
Engine Management – From what I can gather, most chips ‘trick’ the engine management computer into thinking that fuel flow is lower than it should be and tells the pump to add more fuel. This results in a bigger explosion and the extra power output to the drive train. However, is not an efficient way to run the engine and may manifest itself incomplete combustion (black smoke) and potential damage to the drive train due to shock loading.
However, if the extra fuel is added progressively toward the combustion point then the build-up power is smoother. If you also use the right boot with more sensitivity you can achieve the desired effect sooner without so much ‘boot’ and actually use less fuel.
Exhaust System - Another side effect of putting more fuel in is that more air is needed for combustion and with consequent increase the temperature and volume of the exhaust gases.
If fuel economy is your goal then changing the exhaust system will enhance the fuel efficiency. This happens in two ways, a) it assists the spool up of the turbo and be it clears the exhaust gases more efficiently, removing heat from the engine. In some cases it might be necessary to check that your ‘snorkel’ (if fitted) is not causing a restriction to the charge air. I don’t know but this might be an issue with the 200 series and your twin turbos.
Components - To my knowledge the only ‘chip’ that manages fuel flow in this way is the Steinbaur (if you know of another please let me know). Options for exhaust systems are Taipan and Manta.
So there you go, I guess the old adage applies, “if a job’s worth doing, it’s worth doing properly”, which includes driving for economy.
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