GT20 vs. GT2538: Lader Sizes Explained

Hi there,

I intend to install a turbo diesel engine instead of the naturally aspirated 2.9 diesel with 95 horsepower.
to install a short-stroke 2.5-liter turbocharged diesel engine with 126 horsepower at 4600 RPM.
After the installation of a tuning module and some ESP optimization, you should be able to achieve around 150 horsepower.

In the donor vehicle, the TD is charged using a K14 charger.

Due to space constraints, the car's exhaust manifold cannot be included.
So, the exhaust manifold from a Sprinter 2.9 TDI with 122 horsepower at 4000 RPM will be installed.

Now I'm wondering:
The Sprinter was equipped with GT20 and GT2538 turbochargers.
Are they larger or smaller than the K14?
Which charger would you recommend?
The car should ideally have as little turbo lag as possible .
And the loader itself should not be a bottleneck either.
to prevent exhaust backflow. Pre-chamber diesel engines are already prone to overheating anyway.

Best regards, Rod.

I drove the K14 turbocharger in my 250 Turbodiesel, and I have to say it was a great turbocharger. Despite the increased power and boost pressure, it was reliable and is still going strong at 300,000 km.
The turbocharger provided sufficient boost pressure from 1500 rpm onwards.
However, there was a lot of smoke. The ALDA (presumably an engine control unit) should have been adjusted to reduce the amount of smoke before full boost pressure was reached.
However, the K14 has a 4-hole flange, while the Krümmer (exhaust manifold) you want to install has a 3-hole flange.
The loader for the Sprinter will likely arrive a bit later, but it will have more power reserves.