I've just sealed a deal on a 97 C5 (A4 with G90 and Z51) with 15k miles, 1-owner from new and a full set of service manuals :) Pretty impressive acceleration, but I'm already thinking about how to make it even more impressive... the pin you to the back of the seat variety! First-up, I'm considering Borla Stingers (not for the negligable performance benefits, but for the sound) and a Blackwing intake. Secondly, and the reason for this post, I'm considering an aftermarket torque converter. I'm looking for something that will give me a better launch and better acceleration at all speeds. The car will be totally street-driven and a daily driver (I do 20k miles per year). I don't want any looseness (this is my first auto, I've been a stick man up till now). Having searched through the archived posts here, it seems the Pro Torque 2400 might be a good choice. Anyone agree or disagree? Also, can someone please explain STR in simple terms? I know it multiplies the torque available at the wheels at a given engine RPM, but does this mean that a TC with an STR of 2.0 generates less torque at the wheels as a TC with an STR of 3.0 given the SAME engine RPM?? Also, if I go for a TC with a 2400 stall, will I still be able to accelerate gently in normal/town driving conditions? What RPM's would be required to get the car rolling? Lots of questions, I know... but I'm very new to autos. By the way, I've already looked at http://www.converters.cc (Yank site). Thanks for your input guys :)