ENG-19, Turbo Identification
As more and more 944 Turbos are becoming modified for increased performance, one of the popular and least expensive ways of increasing performance is to replace the K26-6 turbo used on the early 951s (1986-1988) with the K26-8 turbocharger used on the late model 951s (1988.5-1991).
Unfortunately, if you buy a 951 that's already been modified, unless there's a record of the upgrade, you may not know which turbo you actually have. Peter, a Rennlist member, has come up with a way to identify the difference between the K26-6 and the K26-8. He has graciously allowed me to share that information here in the Garage Shop Manual.
The basic difference between the two turbos is that the K26-6 has approximately a 1" square flat spot on the turbine housing which the K26-8 does not (picture below).
With the turbocharger in the car, you can shine a flashlight down alongside and just in front of the engine oil dipstick.
Then if you look at a 45-degree angle from the front towards the bottom of the dipstick, you should be able to clearly identify if the turbocharger has the 1" flat square. If it has the square, it's a K26-6. No square, it's a K26-8 (see picture of a K26-6 below).
Clark's Garage © 1998