Mabotech M520H Turbocharger Swap


After driving with a Shuenk IS38+ turbocharger for the past four (4) years I was ready to try something different. The Mabotech M520H is a decent size up from the IS38+ having a compressor that is 51/69 mm compared to the OEM IS38 size of 45/58 mm.

Mabotech M520H Turbocharger
Mabotech M520H Turbocharger

Results on the Mabotech website showed that the M520H is likely well-suited for a new phase of testing with my GTI, namely looking at how well parts perform in support of a “hybrid” turbocharger that is capable of higher power output.

Mabotech M520H Turbocharger
Mabotech M520H Turbocharger

I’m looking forward to trying a ball-bearing turbo, although the step up in the size of the compressor, and turbine (57/52 versus ~55/47 for the IS38), will confound the benefits of the ball bearings insofar as a comparison with the boost onset of a journal bearing IS38+ is concerned.

Mabotech M520H Turbocharger
Mabotech M520H Turbocharger

With the tire traction of my FWD GTI already posing issues with data collection I anticipate the Mabotech M520H turbo to further complicate some of my efforts.

Mabotech M520H Turbocharger
Mabotech M520H Turbocharger

The Mabotech M520H uses a custom turbo inlet elbow to match the 60 mm turbo compressor inlet (versus 49 mm for an IHI turbo).

Mabotech M520H Turbocharger
Mabotech M520H Turbocharger

On the outlet end of the compressor housing, the M520 accepts an IHI-compatible turbo muffler delete, something I am glad for since I monitor the temperature exiting the compressor as well as the pressure at the compressor outlet using a 034 Motorsport turbo muffler delete.

Mabotech M520H Turbocharger
Mabotech M520H Turbocharger


8 thoughts on “Mabotech M520H Turbocharger Swap”

  1. Its described as a “+500whp capable MQB turbocharger”.
    Their graph shows 511 engine HP.
    The claim is not supported by the data provided.
    A flat torque curve from 3500 to over 6000 is quite different compared to say a G25-660.
    I’d be cautious of a less than 2% failure rate. That’s 1 in 50 customers are potentially going to have their engines destroyed.

    1. I don’t believe the dyno charts are showing Engine HP. I’ve used a DynoJet dyno several times and never had output presented as Engine HP. I don’t recall the WinPEP application having that conversion as an option, and since the device measures at the wheels, I presume those charts are showing power at the wheels.

      I’m not understanding the point you are making in comparing the torque curve of this turbo to a G25-660.

      A less than 2% failure rate would be less than 1 in 50 occurrences. A failed turbocharger does not necessarily lead to a “destroyed” engine. You need to determine the rate of turbocharger failure causing engine failure in order to compute the cumulative probability of a turbocharger failure leading to an engine failure. For example, if failed turbochargers destroy the engine in 1 out of 10 occurrences, then the probability of this turbocharger causing an engine failure is “less than” 0.2%.

      It’s difficult to judge if the turbo failure rate is good or bad compared to other options since I don’t recall seeing this value being reported for other turbos, and “less than” indicates a range of possible values that are below 2%.

    2. Graph is showing WHP not engine hp. Any torque curve is tied to octane, tuning and overall setup, a drag oriented setup will have a different torque curve than track or street optimized setups. I don’t recall any other company showing reliability as a selling point.

  2. Do they (Mabotech) not have compressor maps for it?
    The likelihood of failures can be reduced by limiting the turbo speed, provided such recommendations exist.

    1. Not that I am aware of. The only turbo I know of that is specifically for this platform and has a compressor map is from Garrett. I’ve never seen a map for an IHI turbo, I would be very surprised to find one of these smaller aftermarket businesses expending the money to have a compressor map created for their compressor wheel.

      Also, you then need a turbo that is modified to accept a speed sensor and logging equipment to monitor the rotation speed.

  3. I’m eager to read your review on this. I’m on the Mabotech M520H, but EA888 Gen3B. I found the low end lag is pretty bad. I guess due to engine limitations.

    Love your past reviews! Best resource ever when deciding which upgrades to go for!

    1. Thanks!
      I’m looking forward to seeing how the experience changes with a larger turbo. I’m already planning to tweak my DSG tune using Stratified’s refinement option to account for the slower spooling hybrid. A comparison of spool times with the IS38 will be something I measure.

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