Well, Senor Luna is correct. AR stands for Air Research. I suspect that by a big percentage the turbos in use are Air Research units. I have looked at a number of turbo equipped Benz and I have not seen the KKK model, at least that is what I think.
I wouldn't mind a good rebuild unit, but they are expensive, and if I have a used one that is good i will do that. Matter of fact the one I am going to use comes from an 83 that I bought a number of years ago from an instructor at the Knoxville TN vocational Diesel training school. Now he did teach only electrical classes, but he had use of the entire shop to do whatever, and he gave up on the car with about 450,000 miles on it, because of a failure on the nose of the crank. Now they repaired that crank with a JB weld type product that contained titanium and the ran it for about 75,000 miles with that repair. He really liked that car and drove a round trip daily of about 200 miles.

__________________
Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!