Some time ago I saw a thread on
Jaycar Electronics.
It seems to me that it should be relatively easy to make it using a microcontroller that takes MAP/MAF/O2/EGR sensor and remap them.
There are some super-cheap parts with DA/AD and microcontrollers like this (
http://www.atmel.com/dyn/resources/p...ts/doc8069.pdf). The only problem is what is the range needed?
What do you guys think?