Time for my 6 penneth worth I guess as I have used these boxes.
the particular one I used was ordered specific to the exact model you had (rather than just a generic engine size) so information on that engine and its specs are stored in a chip in the box. They plug in to the end of the common rail on a diesel and use the same connector that you unplug to daisy chain the box into line and despite what Amar has said no codes have ever showed up on any workshop scan Audi have ever done on cars I have used them on. I guess if you were worried about that and had VAGcom you could run a scan and then reset everything.
Its a bit different for me I guess as I am using them for a mixture of fuel consumption increases plus a small power/response benefit and the particular box I use has settings from 0-100 which are settable, 100 being the highest performance and 1 being the highest fuel economy. When you set them up you go through a specific process of starting at a low number (20 or 30) and raise the codes gradually whist checking the car for idle and response and of course any warning lights. I've set mine at 50 to date as anything above 60 Isn't recommended for day to day road use but more for performance use and track days etc.
I do agree with Ian on the uplift benefits vs cost and inconvenience and all I can say is that both the ones I've used so far have had great power uplifts but still genuinely increased fuel consumption, which does kinda make you wonder in these fuel conscious days, why dont the manufacturers extract more of either from their engines in the first place? The answer, I think, is usually down to "Range/Model Positioning" for price vs spec etc and to ensure that everything neatly fits into the box they want it to fit into to market it 
Racechip's explanation of how it works and comparison to OBD tuning is here - http://www.racechip.de/en/chiptuning-what-is-it/
__________________
Confidence is the feeling you have before you know better . . . . 
Audi A8 D2 3.7 Quattro Sport 1999 FL - Melange
2nd Place Winner - A8-Freunde Annual German Meet 2012 at Edersee
20" x 9" Bentley GTC Wheels with 385mm W12 Front Discs & Bentley Caliper Covers, Front Lowered on Coilovers, Xenons, Combined DRLs and LED Foglights to modified OEM front fog lamp position, Alcantara/Leather, Full Black Alcantara headlining + pillars and blind shelf, Bespoke Flat Bottomed Sports Steering Wheel, Dark Myrtle Wood, Autodim Mirrors, Bose, Blinds, Digital TV, Ski Hatch, Modified rear exhaust section for extra V8 Burble 
Audi S8 D2 Final Edition 2002, Avus Silver with Red Leather Interior
Tiptronic with Sport mode button, Sony rear entertainment package, Bose sound system, Audi Navigation Plus, 20 inch Final Edition alloys, Full Cat Back Stainless Milltek exhaust, giving a great V8 burble
Audi A8L D2 4.2 Petrol with LPG - Ebony Black
Audi A8L D4 FL 4.0T Petrol twin turbo - Havana Black
Audi A2 1.6 FSi Sport - Dolphin Grey with Votex body kit and Red Leather Interior
and some other A8's A8L's and Mercs
Last edited by Architex_mA8tey; 21st December 2012 at 04:18 PM.
|