KO3 or KO3S ?

[insanekiwi]

My car is a South African 5 door import to New Zealand. Has a key hole in the boot lid - and makes about 140kw at wheels on dyno (which is pretty accurate). I would think that it probably is K03s?

[VWindahouse]

Mine is a 2006 build with the key hole and makes 142kw atw so just over 190hp. What do you think, Ko3s also?

[insanekiwi]

Yeah - haven't heard any MK4 Golfs with K03 making that much power with chip / exhaust / intake / DV alone. They need to take a little further to get power.

[seangti]

05 - 06 PGTi in South Africa had the K03
06 up had the K03s
I made up my own way of distinguishing the difference. (not guaranteed)
PGTis without a key hole in the bootlid have K03s, those with the keyhole have the K03.

That'd mean the 08's have a K03, which means the lower power turbo yeah?? Maybe they did that as forethought compensation for the gearboxes in the early models

Not that it phases me, with the tune and what not, it still goes well.

[DeanB]

That'd mean the 08's have a K03, which means the lower power turbo yeah?? Maybe they did that as forethought compensation for the gearboxes in the early models

Not that it phases me, with the tune and what not, it still goes well.

based on what JK8 posted if you have an 08, you'd have a K03s ... someone like Guy at APR or JMac would probably be able to confirm

[noone]

I don't think that's correct, never seen that before.

Bw dont really call them a S or otherwise, I believe it's more tuner talk...

[DeanB]

I thought there was a difference in the number of blades ? Can remember reading that somewhere, but can't find it now

[Guy_H]

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
pressure.

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
limit.

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 TurboDriven.com - BorgWarner Turbo Systems.

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

Check the part number on the turbo itself - I don't have any Polo ones lying around any longer now. The slightly Larger version (we never called it an "S") was found in Australia on the late 8L A3 drive by wire (132kw standard), so I'm pretty sure the Polo is a "regular" K03 for the 110kw motor.

[clicht]

awesome, thanks Guy !

[Tuning Dynamics]

My experience would say the polo Gti only has the K03s on it.
both in 150 and in the 180 bhp form.
Difference in the K03 to the 's' is the 's' has the 8 blade compressor wheel and the K03 has the 12 blade. Inducer size is 2.1mm bigger and exducer is 1mm larger i think.
Never ever seen the polo with a K03 on it.