^ ceramic coated exhaust housings solve that problem... and also reduce spool time by several hundred rpm... add to that a ball bearing turbo that reduces lag even more... and a properly sized turbo to start with for the engine and the idea of "lag" has all but disappeared...

most people that complain of turbo lag haven't really experienced a properly built turbo system and often are just repeating a catch phrase of the automotive world used by reviewers ... take a look at the torque curve and response time of the 1.8t and 2.0t from VW... there are examples that have plenty of turbo lag suh as small 2.0 4 cylinder engines running GT35 or bigger units that are popular with the tuner crowd now a days but they produce over 500 hp and a were built just for quarter mile racing ...