Ever since the Sierra Cossy turbo came out in 1986, people began to play with them. Not long after, Ford brought out their RS500 of course, boasting the Garrett T4 turbo, and it’s that very turbo we have been running since the early 1990s – albeit a tweaked version, like you do.
From 1986 and into the 90s, all sorts of development went on, with hybrid turbos boasting ceramic ball-bearing technology, twin scrolls, fancy shafts and external wastegates and so on. But this is something we’ve always shied from, even though all of our competition have dabbled in it in one way or another.
So when we stripped the engine in the winter and found that our good old trusty CR Turbo T4 was in need of a service, we…
