Turbocharger: Can a Gas Engine Fit a TDI?

Can a turbocharger from a gasoline engine (e.g., a 1.8T) be used on a TDI engine? The temperature stress should be manageable, but does the geometry fit?
Unfortunately, my A2 1.4 TDI has a Garrett GT12 turbocharger with a wastegate. Therefore, I can't use a VTG turbocharger because I would have to completely rework the entire boost control system.

Regards,
Thomas.

Hello A2TDI,

Generally, yes, because the exhaust temperatures in a gasoline engine are significantly higher. However, for proper tuning, the K03 turbocharger from KKK, in its 1.8T version, is likely too large for the 1.4 TDI. But the main problem for installation is the completely different flange patterns and mounting conditions of the 1.8T. A turbocharger from the good old 1Z (90 hp 4-cylinder TDI) would probably fit better. It also has a wastegate valve with a pressure control vacuum actuator. And with a bit of luck, even the turbine inlet flange might be the same.

Best regards, Leo.

Okay, I'll join Leo on that.

I also think that the installation itself isn't entirely straightforward, but with skilled hands, it's certainly doable. I would also opt for a 1Z turbo. However, it's probably a question of price. In my opinion, the "tuners" on eBay are making a killing when it comes to parts for the 1.8T. I would also try to get something from the 1Z. Just be careful that the boost pressure stays within reasonable limits; I'm not sure what the engine can handle. We ourselves drive an A2 1.4 TDI and are generally very satisfied, although the A2 TDI 1.4 with 90 hp pulls much better, but isn't really faster due to the seemingly identical gear ratios. As far as I know, they only gave that one a VTG turbocharger and a modified air intake manifold.