I have enclosed a picture showing the different KKK turbo compressor wheels that Porsche has used. My main interest is to show others the difference between the stock 993TT K16 wheel and the GT2 K24 street turbo wheel. The wheel on the far left is a stock wheel, next to that is the K24 wheel, then a K27-7200 wheel 964 Turbo, and a K37 wheel (not used on any Porsche, it is a marine application), the lower row is a 930 K26. The main difference between the K16 v K24 is the inducer diameter, or the diameter of the intake tip of the wheel, the overall wheel diameters are close to the same. The sizes are 1.596" vs 1.6800". At the shop we are machining the stock compressor wheels to accept the larger wheel. This is similar to the GT1 turbo.

 

If the overall diameter is roughly the same is it just the inducer diameter and the balde design that differs?

Is the K24 any lighter?

How much modification is necessary to the stock bodies to accept the K24 rotor?

Interesting work -

 

WillBank;

When you install a larger wheel a template is made of the new wheel and you cut the material out of the housing. In this case 0.084"/2 is taken out You then have to re-balance the turbo because of the added mass. This is a easy modification.

 

Kevin,

are these the cold end wheels or the hot end wheels ? It is pretty hard to see any difference between the first and the second wheel from the left. How much performance difference is there ?

So the GT2 street turbo has a bigger hot wheel or a bigger cold wheel or both? I guess I am really confused now

 

VS

The picture shows the compressor wheels which is on the intake side of your engine (cold side), typically the turbine side or (hot side) consists of the turbine wheel and shaft as one unit. Whenever, you see a wheel by itself, it is the compressor side. The street GT2 does have both a larger turbine diameter, exducer, and a larger compressor wheel like the one I pictured. This inexpensive upgrade would benifit someone that has a leaking turbo and or someone that wants to add around 30-40hp to his engine.

 

CJV;

The new GT2 measurement is the same diameter as the 993GT2 K24 wheel, which doesn't mean much because the 993TT is roughly the same. However, what makes the difference is the inducer diameter, that is what we need to find out. Like I said earlier, the K24 is .084" larger than the K16.

An interesting note is that the turbine size is 2mm larger than the stock 993 TT K16 wheel. 57mm vs 55mm

 

Kevin,

Thank you for the explanation, it is all getting more and more clear. Ok, now the inducer - is that the raised part around the center? It does look bigger for the second (K24) wheel.

<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

 

Damn, my little turbo on the Supra only has a compressor size of 2.67.

 

On a Supra I've seen a turbo with a 6" inlet and 12" housing !!! You wanna keep your fingers and small animals away from that sucker!