Turbo boost: Stock TT = 0.8 Bar or 11-12psi boost Most aftermarket chips are: 1.0-1.1 Bar = 14-16psi boost Stock 180hp TT turbo name = K03 Aftermarket larger or 225hp TT turbo = K04 Chips usually come in two flavors: "Spare ECU"(you swap the entire silver metal container with your stock one) and "Socketed"(your stock ECU is opened, the stock chip desoldered and a socket is installed which allows you to remove the aftermarket chip and reinsert the stock chip or send the aftermarket chip out for new coding) Possible problems with chips: Chip MAY or MAY NOT void warrenty depending on dealer. Chip MAY or MAY NOT lower the life of the engine Chip could possibly damage turbo if not allowed to cool down after hard runs. Chip could cause pinging(detonation) in high heat or with poor fuel(91 octane or less) The 1.8T engine hasen't been around long enough(since 1997) to tell how much if at all a chip effects engine life. But it seems the engine is able to handle this and more... Advantages to chipping: Less turbo lag More horsepower and torque Better acceleration Better gas milage Some chips can smooth out jerkiness or lag problems YOU GO FAST! Brand names: TAP, APR, Garrett, Neuspeed, AMS, MTM/Hoppen, Wetterauer, Autothority, Superchips and probably more that I don't know of or am forgeting. Helpful links to learn more about turbos or these fine companies: Don P's Audi Zonehttp://www.audizone.com/ AWE Tuning:http://www.awe-tuning.com/ APR: http://www.goapr.com/Home/home.html Wett: http://www.chip-tuning.com Garrett: http://www.giacusa.com/welcome.html TAP: http://www.tap1.com Neuspeed/Greedspeed:http://www.greedspeed.com Thats all I can think of off the top of my head. I am sure there is more out there and I am sure that if you look around Audiworld more you will find LOTS of info. I know I did. Hope this helps in your quest! -Jenner '00 180QX TT Garrett, H&R Sport Springs, LLTEK tail light covers, LLTEK floor mats