924Board.org

emoore924 · Joined: 13 Apr 2004 Posts: 2815

Heh heh, I think I know where the other one is

Geoff, check your PM.

emoore924 · Joined: 13 Apr 2004 Posts: 2815

Here is some information regarding the standard K26 924 turbo unit you might find useful, especially if you are considering the installation of an intercooler or want to do a few flow calculations.

It should be noted that the results of my flow calculations show 2.25” intercooler tubing should be more than enough to take the 2.0l motor beyond 250 HP, maybe more. If you are interested in the details, please PM and I can send them along with an explanation. Or just read Maximum Boost. All the necessary calculations appear there and are thoroughly explained.

All of the measurements were taken off a stock K26 unit with a blue ID plate.

K26-2664-G4.10
81 725 0959
5326 970 6406

All measurements were done with a set of hand calipers and a ruler, and should be considered “informational only” rather than exact.

Output from the CIS air meter hose to fresh air input to turbo: 2” ID
Output from compressor side of turbo: 1 5/8” ID

Shortie tube is little S-shaped cast alloy tube 931 110 160 01 1R, connects from o/p of turbo to elephant trunk tube to TB.

Input to shortie tube : 1 5/8” ID (matches o/p from turbo)
Output from shortie tube: As it turns out, it has the same area as a 2” ID round tube, but the shape is oval. It is essentially a 1.5x1” rectangle in the middle, with .75” radius half-circles on the ends. Therefore area of the oval = area of the rectangle + area of each half-circle on each end…capiche?

Note: The output from the turbo housing should be carefully matched with the input to the shortie tube. In my case, the hole in the cast turbo housing DID NOT line up at all with the nicely machined and centered input hole in the little shortie tube – easily wasting several HP due to restricted flow and turbulence at this critical point. The IDs were essentially equivalent, but the hole in the turbo housing was well and truly off from center. Effort spent lining up the holes in these two parts would be well worth it.

Exhaust manifold output to turbo input (the 3-bolt flange on the turbo): 1 11/16 = 41mm

Output of turbo to exhaust (the 4-bolt flange on the turbo): 2 3/16 = 56 mm

Various and sundry other numbers (?=couldn’t read the number):
Compressor housing: 5326 ?01 5190
Number on Cover for turbo bypass piston: 5326 102 3303
Other numbers on compressor housing (in little circles, looks like a euro-format date of manufacture to me) 18 5 81
More #’s on compressor housing: 5326-5791-=0 67.2
Even more #’s on compressor housing: 5326=5790n=0 61.2

If you are interested in any other measurements, please PM me and I will add them.

NEMESIS · Posted: Thu Feb 22, 2007 1:39 am Post subject:

flosho · Posted: Fri Feb 23, 2007 1:21 pm Post subject:

I got a question..

How does our turbo being .49 trim actually compare to other turbos, like the stock srt-4 turbos, evo3 16g, etc?
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[This Space For Rent]

flosho · Posted: Sat Feb 24, 2007 7:05 am Post subject:

ideola · Joined: 01 Oct 2004 Posts: 15548 Location: Spring Lake MI

Here are the numbers off of what I believe to be a series 2 K26 turbo I acquired a while ago in a "package" with a bunch of other stuff:

Tag:
Grosse: K26-2660GA4-10
ATL-NR.: 82 995 0242
AUSF.-NR: 5326 970 6022

Turbine Housing:
5326 101 6365

Compressor Housing:
5326 101 5190 F
15 4260/2531

Compressor Wheel:
5326 123 2007

Turbine Wheel:
26 B 94 9 26 B
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erstwhile owner of just about every 924 variant ever made

ideola · Joined: 01 Oct 2004 Posts: 15548 Location: Spring Lake MI

Numbers off of my rebuilt series 1 K26 turbo (rebuilt by Michigan Turbo in Grand Rapids, MI):

Tag:
Serial No: 1G2706-1
Part No: 5326-970-6407

Turbine Housing:
5326 101 6365

Compressor Housing:
5326 101 5190 F
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erstwhile owner of just about every 924 variant ever made

ake1ro · Joined: 22 Nov 2007 Posts: 1 Location: GREECE

Does anyone knows about the KKK K26 5326 970 6482 specs and HP that goes out from this turbo?
Thank you

gegge · Joined: 27 Jul 2007 Posts: 1124 Location: Sweden

ideola · Joined: 01 Oct 2004 Posts: 15548 Location: Spring Lake MI

Complete 931 turbo part listing and details here. Image courtesy of turbo3k.com

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erstwhile owner of just about every 924 variant ever made

ideola · Joined: 01 Oct 2004 Posts: 15548 Location: Spring Lake MI

Well boys, I've just confirmed it. The 951 K26/6 water-cooled bearing housing is part number 5326-151-0089. (The KKK part number listed in the Borg-Warner catalogs is 5326-150-0020).

Why should you care?

Because it is a direct, bolt-on replacement for the 931 bearing housing. Take your SI or SII K26 turbo, get the 951 bearing housing, send the bits to your favorite rebuilder, and voila, you now have a water-cooled 931 turbo unit. The unique 931 top and bottom oil lines / bracket fixtures are a direct bolt-on to the 944 bearing housing (John at Majestic confirmed this for me).

Of course, you'll need to plumb in the water lines and a pump. For this you can either source the stock 951 components (pump and relay, which operates the pump for 30 seconds after shutdown), or you can go aftermarket (for example, a Davies-Craig electric booster pump). The easiest way to tap into the coolant circuit is to tap the cold and hot side respectively of your rad.
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erstwhile owner of just about every 924 variant ever made

gegge · Joined: 27 Jul 2007 Posts: 1124 Location: Sweden

To continue the watercooled housing issue.

I made an easy hybrid just by swaping turbine housings. The bearing got the exact number Ideola mentioned in previous post, 5326-151-0089.
The original K26/8 from 951 fits perfectly in a K26/6 931/937 hotside. (Well not exactly original since i got a larger compressor wheel, but that is another story.) The point is that a late 951 axle and turbine is the same as 931.

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Carl Fredrik Torkildsen

924 turbo -81 Carrera GT RESTOMOD
924 turbo -80 Dolomite De Luxe
924 -85 DP kit, BBS RS, M030 and tuned engine
924s -86 Black on black turbo with Fuchs

gegge · Joined: 27 Jul 2007 Posts: 1124 Location: Sweden

I bought something very special at Ebay last week:

5326 970 6024 doesn´t reveal it´s pedigree - maybe Porsche 956 does

Porsche 956 was a pure race, later called 962. The engine was a 2,65 l twinturbo boxersix with 626hp@8400rpm.

It´s a brand new K26 with K27 backplate, housing and 3060 compressorwheel. Only oil cooled and a #10 turbine housing. Manufactored in 1987 according to stamps inside the housing. I would say this is evidence of oilcooling is sufficient, no need for watercooling in racing. And since it is a K26, the 931 turbine housing fits like a glove

One K26 with 2964 compwheel and #8 turbinehousing and watercooled bearing housing. One K26 with 3060 compwheel and #10 turbine housing.

Which one is to keep? The compwheel is approx the same, does the diffenence in comphousing make a difference?

_________________
Carl Fredrik Torkildsen

924 turbo -81 Carrera GT RESTOMOD
924 turbo -80 Dolomite De Luxe
924 -85 DP kit, BBS RS, M030 and tuned engine
924s -86 Black on black turbo with Fuchs

ideola · Joined: 01 Oct 2004 Posts: 15548 Location: Spring Lake MI

gegge · Joined: 27 Jul 2007 Posts: 1124 Location: Sweden

Any idea if the K26 has got piston ring(s) or carbon seal on the compressor side? The turbo3k.com site does show two different seals but no explaination (#6 and #11)

I´ve got a crazy idea and would like draw-through the turbo and place the throttle infront of the turbo.

_________________
Carl Fredrik Torkildsen

924 turbo -81 Carrera GT RESTOMOD
924 turbo -80 Dolomite De Luxe
924 -85 DP kit, BBS RS, M030 and tuned engine
924s -86 Black on black turbo with Fuchs