<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:<hr /><font size="1" face="Verdana, Helvetica, sans-serif">Originally posted by Mr T:
<strong>There is a downside to the Unichip, which is the skill and compatency of the mapper. He could either undermap the car or be too keen and end up with **** loads of knock. It does seem expensive since the cost over here is around 400 quid.
</strong><hr /></blockquote><font size="1" face="Verdana, Helvetica, sans-serif">Mr. T, I agree with you on the skills of the mapper. My friend's car was running lean after installing the Unichip box. He then had it recalibrated (while driving, not on the dyno) and has reported some improvement and changes in power delivery point (lower down the rev).
I'm still curious about Unichip or any piggy-bag unit. How does it communicate or "fool" the ECU? With an ECU remap (like Autodelta), it can take various readings (air mass, temp, accelerator angle, etc) and optimize combustion from those readings already built into the ECU. Even if the temperature and driving conditions change, it will work and adapt within a certain parameter.
Now with a piggy-bag unit that "fools" the ECU, does it work differently? I would have thought that it works with just one pre-defined condition. In other words, it's not as adaptive as an ECU remap.