With the V6 having high compression ratio, an eletronic throttle, v-tec on the inlet cam (may be electronically controlled) and possibly (though I am not sure) sequential fuel injection - I would think any remapping which chip companies do 'cheaply' is not re-mapping at all. More like simple adjustments to fuelling across the rev range which is typically very heath-robinson.
It takes a lot of know-how of a particular ECU and engine to begin to be able to re-map a stock ECU over and above very basic tweaks which are often global across the map. Not to mention the V6 is quite a niche car so it is less likely R&D would be possible for mainstream tuners to deal with. Enrichment is the usual method of gaining more HP by chip tuning.
Some of chip companies achieve this by fooling the stock ECU into thinking the engine is running colder ! Other options are 'tweaking' map sensor inputs to fool the ECU into misrepresenting air metering - again causing additional fuelling. Another option is increasing fuel line pressure and so on.
A stock ECU typically has the capability to fuel 10-15% above stock power so making adjustments to volumetric efficiency and exhaust can automatically unlock some of this capacity. I believe the Mk2 V6 has an extremely efficient intake system meaning that it may be difficult to improve on the stock induction to gain any meaningul improvement there.
On turbo cars some of the practices are shark-like in that fuel cut defenders and boost increases which you can do DIY for a couple of quid are charged out at 3-400 quid by 'chippers'.
I am not casting aspertions against any specific companies in this post - just adding some of my knowledge and experiences.
I would imagine a 'group buy' approach is more likely to yield a genuine result
Martin
