+13 hp and +19 Nm at peak – and up to approximately +30 hp and +58 Nm at 4,500 rpm

The BMW G20 330d with the B57 engine is already an exceptionally capable diesel from the factory. However, the higher the engine revs, the more air must reach the intake system and the turbocharger compressor.

This is precisely where our RevDop Turbo Inlet comes in. Rather than simply making the geometry as large as possible, the component was developed using CAD, topology optimization, and CFD flow simulation. The goal is the most efficient, controlled, and low-loss airflow to the turbocharger possible.

For the test, our B57 Turbo Inlet was installed in a BMW G20 330d and subsequently compared against the stock version on a dyno.

The result at peak value

A measurable difference is already apparent at the peak value:

Stock:
368 hp at 3,800 rpm
762 Nm at 2,200 rpm

RevDop Turbo Inlet:
381 hp at 3,800 rpm
781 Nm at 2,300 rpm

This results in +13 hp and +19 Nm at their respective peak values in the documented run.

That alone is already a pleasing result. However, the analysis becomes even more interesting when looking beyond just the highest points of the curves.

Particularly interesting: 4,500 rpm

At 4,500 rpm, the gap between the two measurement curves widens significantly.

Here, the diagram shows approximately:

+30 hp
+58 Nm

in favor of the RevDop Inlet.

And this is the specific range that we find particularly interesting.

Because the maximum torque value alone does not indicate how an engine behaves across its entire rev range. A component may show a comparatively small change at the peak while having a significantly greater impact under higher air throughput.

This is precisely what can be seen in this measurement of the G20 330d: While the curves move closer together in the lower and middle range, the gap increases as the RPM rises.

At 4,500 rpm, the RevDop curve in the diagram is already approximately 30 hp and 58 Nm above the reference curve.

This is a significant difference—and for us, a particularly interesting indication that the optimized geometry shows its strength especially when the engine needs to process a large amount of air at higher RPMs.

Why does the difference grow at higher RPMs?

The turbo inlet is located immediately before the turbocharger compressor intake. Therefore, its geometry directly influences how the air is guided to the compressor.

At higher RPMs, the engine's air demand continues to increase. This is precisely where unfavorable transitions, abrupt cross-sectional changes, or flow disturbances can have a greater impact.

Our approach is therefore not "as big as possible," but "as efficient as possible."

The internal geometry of the RevDop Inlet was developed with the goal of optimizing the usable flow cross-section, making transitions more harmonic, and ensuring more uniform flow to the compressor. CFD development demonstrates optimized airflow compared to the OEM inlet; on the product page, we specify, among other things, 30% less pressure loss and 20% more fluid volume under defined development conditions.

The difference is particularly interesting at 4,500 rpm

+30 hp and +58 Nm at 4,500 rpm are not the maximum peak value of the test, but the difference at this specific RPM point.

This is exactly why we find this figure especially meaningful.

Because it shows that the effect of the inlet is not only visible at a single dyno point. The curves diverge increasingly as the RPM rises.

Of course, a dyno result always depends on the specific measurement conditions. Therefore, we would not derive a universal performance increase for every vehicle from a single run.

But as a documented comparison on this G20 330d, the result is extremely interesting.

Engineering instead of just "bigger"

The shape of the RevDop Turbo Inlet is the result of a development process that began with analyzing the original component and continued through topology optimization, CAD, and CFD development.

The characteristic bionic geometry is therefore not just a design feature. It is intended to optimize where it is technically relevant: in the flow path to the turbocharger.

The component is manufactured from PA12 using SLS laser sintering and is designed as a direct replacement for the corresponding OEM inlet.

Our conclusion

The dyno run of the BMW G20 330d shows two things very clearly:

At peak:
368 → 381 hp
762 → 781 Nm

At 4,500 rpm:
approx. +30 hp
approx. +58 Nm

The large gap at 4,500 rpm is what makes this measurement particularly interesting to us. It shows that the advantage of the RevDop Inlet in this run increases as the engine's air demand rises.

For us, this is precisely the interesting point behind the development:

Not just more cross-section—but a specifically optimized airflow.

And when such geometry is reflected not only in CFD simulation but also on the dyno in a real G20 330d, that is exactly the kind of result we want to see at RevDop.

RevDop Turbo Inlet for BMW B57 Gen2 – developed with CAD, topology optimization, and CFD.

To the RevDop B57 Turbo Inlet