BMW M340d 3.0 B57 xDrive Dyno Test - 335bhp Performance Tuning

In our latest dyno test we had this awesome 2021 BMW M340d in for tuning and testing. After quick installation of our specifically designed Pro + Boost SENT chip tuning box, it was up on the rollers to see what the engine could achieve.

These vehicles currently have a locked ECU with no way to read or write the ECU data. This means that while traditional remapping is impossible, our tuning box can give owners the opportunity to make fantastic gains without requiring a traditional ECU flash. This has the added benefit of being traceless once removed for warranty purposes.

Dyno testing before and after shows healthy gains across the rev range, with a significant increase in power and torque, really transforming how the M340d feels to drive.

Peak power was increased, as we were able to lift it from 335hp at stock, up to 381hp with the box. If you take a look at the dyno graph below you can see how we change that curve (dotted red and blue lines). We give real consistency here, bringing that extra power in as soon as possible, whilst holding it for as long as possible throughout the rev range.

Torque saw some really impressive improvements. At stock the engine produced 725Nm and now 820Nm with the box. Stock figures coming in a little higher than manufacturer quoted at 700Nm, but not particularly unusual to see higher stock figures here, as they can usually push beyond what BMW claim. If you take another look at the graph (solid lines), you can really see where we have applied those gains, allowing those torque improvements to be applied through the revs. Looking at that section around 1800rpm you can really see where we have lifted that whole portion within the revs, giving those gains exactly where it’s needed.

Check out the full dyno test here, across on our YouTube channel: