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KKK Turbo from 1.8t Audi A4
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bnoon  



Joined: 12 Oct 2009
Posts: 607
Location: West Des Moines, IA USA

PostPosted: Sat Feb 20, 2010 11:14 am    Post subject: Reply with quote

Yup, the K03 is crap. The K04 also comes on the new Cobalt SS and the Mazdaspeed3/6 and CX7. Popular upgrade for the K03 is to up the cold side to the K04 compressor and snail to support 300 crank HP area.

The K04 has a few different wheel sizes to support more than 300+ at the wheels (my MS3 is 301hp/320 tq at the wheels with a stock turbo). A few aftermarket k04 billet wheels can make more than 350 wheel hp too. It has a 4 bolt housing though.

If you're going to spend the time to make something like this fit, get a better turbo. The K03 and K04 are journal bushing turbos and have shaft issues which will not last long in high pressure installs without MAJOR attention to shaft cooling methods (turbo timers, cooling mods, oil cooler, etc.). Get something with ball bearings that will last longer and perform better, or at least a more popular turbo that has more options to choose from.
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ideola  



Joined: 01 Oct 2004
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Location: Spring Lake MI

PostPosted: Sat Feb 20, 2010 12:29 pm    Post subject: Reply with quote

Ummmm...pretty sure the Cobalt SS has an Eaton M62 supercharger...
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flosho  



Joined: 01 Jul 2004
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Location: Eau Claire, Wisconsin

PostPosted: Tue Feb 23, 2010 2:42 am    Post subject: Reply with quote

The point was just to compare the mounting flange and see how close they were and see if a lower cost option was available other than custom manifold and turbo.
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bnoon  



Joined: 12 Oct 2009
Posts: 607
Location: West Des Moines, IA USA

PostPosted: Wed Feb 24, 2010 11:00 am    Post subject: Reply with quote

ideola wrote:
Ummmm...pretty sure the Cobalt SS has an Eaton M62 supercharger...


The first Cobalt SS's were SC'ed, the 09's are turbos and kick the butt of the stock SC'ed ones, heck, even stage II and III SC'ed Cobalts would be hard pressed to beat a new turbo one. They use the same K04 series turbo my Mazdaspeed 3 uses. Unknown what their wheel sizes are, but there are only 3 or so wheel choices and not many modifications for the housings.

flosho wrote:
The point was just to compare the mounting flange and see how close they were and see if a lower cost option was available other than custom manifold and turbo.


What is our turbo style anyway? KKK aren't they? K26/K27 style??? Guess it depends on SI, SII, or later style eh??? I'm still sketchy on the details of the tufah turbos...
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ideola  



Joined: 01 Oct 2004
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PostPosted: Wed Feb 24, 2010 12:07 pm    Post subject: Reply with quote

@bnoon
Ahh, wasn't aware the new Cobalts were turbos! Learn something new everyday, as they say.

Re: the 931 turbo, regardless of the series, they are all K26, and the big issue is that they have a completely unique 3-bolt flange on the turbine housing.
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bnoon  



Joined: 12 Oct 2009
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Location: West Des Moines, IA USA

PostPosted: Thu Feb 25, 2010 1:38 am    Post subject: Reply with quote

ideola wrote:
@bnoon
Ahh, wasn't aware the new Cobalts were turbos! Learn something new everyday, as they say.

Re: the 931 turbo, regardless of the series, they are all K26, and the big issue is that they have a completely unique 3-bolt flange on the turbine housing.


Do all of the Porsche K26's use the same hot side housing then? Are there different size wheels for the hot side? I've read a little bit about the turbo you're using on your project. Who was that mad by again???
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ideola  



Joined: 01 Oct 2004
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PostPosted: Thu Feb 25, 2010 2:18 am    Post subject: Reply with quote

bnoon wrote:
Do all of the Porsche K26's use the same hot side housing then?

No. The 931 K26 has a completely unique 3-bolt flange, while all of the other Porsche and Audi versions have a standard 4-bolt flange.

bnoon wrote:
Are there different size wheels for the hot side?

Yes. There were different configurations on the hot side to match the "lug line" (i.e. spool time) to the intended RPM / power band and the CFM capabilities of the hot side. It's important to note that the K26 was used on MANY applications besides the 931, including the 944, several Audis, and even some commercial equipment. As far as I have been able to determine, the 931 is the ONLY application that used the 3-bolt turbine housing, even though the turbine shaft may have been common to several other K26s. However, there were also some K26s with completely different turbine geometries, so important to note that the turbine wheel and it's housing are necessarily a matched pair. A good example is that the S1 and S2 had different lug lines and consequently slightly different turbine wheels and definitely different compressor wheels and housings. As far as I know, the S1 and S2 turbine wheels are interchangeable with the 931 housing, and there is at least one version of the 944 turbine wheel that is identical to the 931 S2 turbine wheel. But that doesn't mean that ALL K26 turbine wheels can be installed into the 931 turbine housing.

-nick catalogued a lot of the 931-specific details in his "all you want to know" thread. Nevertheless, some of the early K26 944 turbine shaft-and-wheel combinations are identical to the 931, which is nice, because you can take the 944 water cooled bearing assembly (inclusive of the shaft and turbine wheel) and simply swap on a standard 931 hot side housing for direct bolt-up onto the 931 mounting bracket and oil lines. The 931 cold side would be directly swapable, or you could go with any of the 944 K2* cold sides, as they will directly bolt onto the bearing housing as well. It's important to do your homework on the turbine wheel, however, to make sure the 944 wheel you get matches the 931 wheel you're replacing, as the wheel and turbine housing are machined to very specific tolerances in order to spool correctly. Hope this makes sense.

bnoon wrote:
I've read a little bit about the turbo you're using on your project. Who was that made by again???

I commissioned Majestic Turbo in Waco TX to develop that turbo. Here is the thread with many details:
Bolt-in off-the-shelf water-cooled turbo for 931

How about some eye candy?

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Joes924Racer  



Joined: 03 Nov 2002
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PostPosted: Thu Feb 25, 2010 2:43 pm    Post subject: Reply with quote

Read it all. This post and the majestic commission.. nice they did a nice job. Those housings are hard to find.
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Dutch924-racer  



Joined: 23 Jul 2007
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PostPosted: Sun Nov 20, 2016 5:39 am    Post subject: Reply with quote

Porsche is back to a 3-bolt flange


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