Here are the other important things to compare. I tried to take a picture showing the finish of the two wheels. I think it came out pretty good. The EFR wheel is a machined forging and you can see the feed rate of the machining is very slow making these pretty much polished!
Compare the GTX wheel and you can see how much faster they machine the part by the deeper grooves. Borg Warner really took their time making these new turbos really nice.
Its hard to see in this pictures, but the GTX wheels are much shorter compared to the EFR compressor wheels. Its very interesting up close as they shape of the fins are very very different. Its like comparing fins on a ceiling fan to fins on a jet engine.
The one part that i think really make people go crazy is the Gamma Titanium turbine wheel. Its finish is very very nice. The flat bottom of the turbine wheel makes it very strong and also more aerodynamic compared to the split Garrett type. Again the turbine wheel fin design is different.
The Garrett turbine wheel is shaped different, and also has a much thinner cross section. You can almost make it out in the pics. Brock at Borg Warner told me that you have to go up a size in the EFR turbine wheel OD, to compare against a Garrett. In this case 70mm EFR will be similar to the 60mm GTX. Which this makes more sense base on the overall volume the turbine wheel being slightly less with an EFR of the same given OD as a Garrett.
Beside that stuff here are some other cool pics from BWTS.
This cross section shows why the turbo is so much longer. The dual caged ceramic ball bearings are spread far apart for stability, notice the 4 oil seals (Garrett has 2), the oiling mechanism is designed to push oil to the front and back bearings, the coolant jacket spreads deep into the turbine wheel area, the really cool BOV return port and all the other really cool stuff. You can really tell this is over built and designed for abuse.
Here is the GT3076R. You can't see the bearings in this but you get the idea.They don't recommend going 20 degrees of kilter with the EFR, but with the better oil slinger and dual seals on both ends, i bet you could do close to 45 degrees.
These are the 3 main castings used on all the current models of the turbos.
Now the fun begins trying to make this fit!
EFR Turbo Technical Brief
Here is a very in depth article about the EFR turbos and how they came to be. This article is what really got me going on these turbos. Never before has turbo company done this kind of public documentation.
Click Here to Download EFR Turbo Technical breif.pdf