The Audi C4 platform has been a perennial favorite tuning platform; just the other day in my Facebook feed a quick video popped up of an original S4 putting out over 1,000 horsepower at a staggering 11,000 RPM on a dyno. If that alone doesn’t tell you a bit about the stoutness of the turbocharged 5-cylinder mill, then perhaps the multitude of 400+ horsepower examples burbling happily along would. At their right foot the owners hold back a soundtrack of 5 barking cylinders which produce tunes that sound roughly like Pavarotti was being squeezed to death by Zeus, replete with lightning bolt cracks and flashes of fire in the sky with every shift. But properly building an AAN or other turbocharged 5-cylinder to handle really heavily increased boost will quickly double the purchase price of your budget S4/S6. So, is it a better proposition to buy one that’s done?