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the deal finder!
15,574 Posts
Discussion Starter · #1 ·
Well, i know that ONE8T has a thread in the info forum that talks about this, but this has some info that wasn't in ONE8T's post. For reference, here is the thread:

Also, i wanted to note that this info is most likely for the trans 1.8t, not the long 1.8t in the passat/a4. I found it interesting that they said that the only performance difference between certain 150hp and 180hp version is the actuator, and that even some turbos with a larger compressor is rated for 150hp also (and obviously some at 180hp).

Just a thought - i wonder if the acutator can be upgraded on the 150hp k03 to make it closer to a k04.

Dear Sir,
thank you for your interest in our products.
First of all, we don't produce any turbo that we call K03S. But I hope I can
answer your questions with the following explanations.

All the following turbos have the same installation dimensions and
thermodynamical performance. The differences are only in the actuator that
opens the turbine bypass valve:
K03-011 (5303 988 0011) 150 hp, 65 N actuator
K03-026 180 hp, 85 N actuator
K03-035 180 hp, 85 N actuator
K03-044 150 hp, 65 N actuator
K03-045 156 hp (Ibiza Cupra), 85 N actuator with 2 ports
K03-049 150 hp (Sharan/Alhambra), 65 N actuator
The 180 hp versions have an actuator with a higher opening force due to the
higher exhaust gas pressure (which is a consequence of the higher boost
pressure). Otherwise the valve would be pushed open by the exhaust gas

The following turbos are a further development (since 2000) and have an
improved and slightly larger compressor while using the same turbine (still
with the same installation dimensions):
K03-052 180 hp, 85 N actuator
K03-053 150 hp, 85 N actuator
K03-058 150 hp/180 hp, 85 N actuator

Consequentially, putting a 180 hp turbo on a 150 hp engine will not bring
about any change in performance, but putting on a K03-052/053/058 instead of
the older versions will bring a slight improvement in engine efficiency.
Additionally, with re-mapping the ECU you can achieve about 215 hp without
danger of overspeeding the turbo. With the older turbos, 195 hp is the

With the K04 that's also commonly used (5304 950 0001) the power output
should not be more than 220 hp. That means, changing a K03-052/053/058
against a K04 does not make a lot of sense.

I hope that these details answer your questions. If you need more info, one
of our service distributors will be glad to help you. Their addresses are on
our website
Register or Login.

Mit freundlichen Grüßen/Best regards,
BorgWarner Turbo Systems GmbH
Sales IDS - Technical Support
Christian Seibert

11,873 Posts
d.passat you posted that pic and that turbo aint on the list. i see the o26 but the turbo you show is a 029. are there many diffrent number;s on these turbo's as models as per say 026-034 fall as the 026 model... sorry im alil confused
says 058 on with is a 150/180 HP turbo which makes sense.

109 Posts
dum question but you sayin i can change the actuator and get an extra 30 bhp (i know fuelin would have to be sorted)
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