|
|
Posted by David Sherman [24.32.202.83] on Tuesday, September 08, 2009 at 20:05:50 :
In Reply to: Slightly OT. Chips fopr Diesel Truck posted by Mark in NJ [151.198.55.114] on Tuesday, September 08, 2009 at 15:40:27 :
Sounds like the updated version of the platinum screen and propeller you put under your carburetor. HP, fuel economy, engine life, and emissions are tradeoffs. You get to choose one, or at most two. There's an engineering saying "Faster, better, cheaper: pick two" I have to believe the factory chips are set up for an optimum balance, probably favoring fuel economy and engine life. About all that a chip can do is increase the maximum fuel rate, like turning up the injector pump on a non-electronic system. Maybe it can tweak the injection timing too, but there isn't really much you can do with that unless you can adjust to the type of fuel in real time.
Turning up the fuel rate limit will certainly give you more power, but once you get black smoke, you don't have enough air to burn that fuel, so you're just wasting fuel and coking up injectors. If you could increase the turbo boost at the same time, to give it enough air to burn the extra fuel, then you'd have a real power improvement, but then you need to start worrying about exhaust temperature, lest you burn up your turbo. I suspect that for all but extreme cases where you're using the engine for something much different than average truck usage, the hot-rod chips are just snake oil.
If the chips allowed you to adjust all the parameters in real time while you're driving, and gave you lots of feedback about things like instantaneous MPG, instantaneous HP, turbo boost, and exhaust temperature before and after the turbo, then it would be fun to have one and play with all the variables. You could put it in "black smoke" mode when you wanted to impress somebody, and then carefully tune it for maximum fuel economy while you're driving at a steady speed on the freeway. But in general, the engineers who programmed the original setup probably did a pretty good job of it, and to think that you can improve both power and economy by simply changing a few constants in the math that the chips control is like sticking magnets on your fuel line or any of the other quick, cheap (or expensive), and useless fuel-saving gimmicks that people have been peddling as long as there have been cars.