Kevin

I have just received the new KKK Billet compressor wheels from the factory. These are the latest designs along with the latest technical advancements in turbocharger development. In my posted picture I have shown from left to right, stock compressor wheel K16, next is the stock K24 GT2 wheel, the next on is our new Billet forged wheel, this wheel will finally allow us to overspeed the turbocharger so that we can continue to get the usable horsepower in the upper RPM's. And for the all out got to have the latest techno guys a Billet Forged Titanium wheel, which is 30 times stronger than the factory cast compressor wheel.

As seen on my calipers the new Billet wheels are identical in size. The major diameter are at 63.48mm vs 60.57 for the stock wheels. The inducer size is what is considerable, 44.17mm for the new wheels versus, 40.56mm (stock).

The major implications for these new designs are to add a added measure of strength to our turbochargers and adding more air with keeping the smaller K16 turbine wheels. However, all of these wheels can be installed on the K24's.

cobra06

So these can be placed in a stock K16 housing?.
What are the details of doing a conversion, and what kind of H.P. gain over stock should one see running at 1.1-1.2 BAR?
Thanks

Kevin

Cobra;

I have not received the maps for these wheels yet. I should have them on Monday. These are designed for the K16 & K24 application. They will really perform in the hybrid K16 mode. These can be cnc'd in the K16 housings.

rmrmd1956

Kevin, could you explain in detail, the difference between K16, hybrid K16, K24 and GT1 street turbo. I am so confused, I've no idea what is in my car (EVO Stage 4) and what my next step is in turbo upgrading!?

Kevin

rm;

If you look at my first post it lists the size differences between the K16 and K24, the turbine wheel is also 2mm larger on the K24's. This larger wheel requires more air (exhaust) to spin the shaft. The drawback with the K16 is the lack of topend. The GT1 street turbo is basically a K16 with the street GT2 K24 compressor wheel (known as a 2007). The K16 hybrids are most often the build up of a GT1 turbo. With the larger wheels one can sustain larger amounts of boost at the upper RPM range.

Is there anyway that you can read the ID tag on your turbo's? If you remove your inlet air pipe to your compressor housing, and get a rough measurement of your compressor wheel. I can then help you with what you have. I hope that this helps some....

By the way, the larger wheel shown supports over 600hp and 1800ft/pounds of torque.

GlobeTrotter

Isn't there a disadvantage to having a larger turbo(wheel)???? Because it results in a greater lag time thus it affects the lower RPM's?? something to that extent..if you could validate this or clarify. thanks


[quote]Originally posted by Kevin:
<strong>rm;

If you look at my first post it lists the size differences between the K16 and K24, the turbine wheel is also 2mm larger on the K24's. This larger wheel requires more air (exhaust) to spin the shaft. The drawback with the K16 is the lack of topend. The GT1 street turbo is basically a K16 with the street GT2 K24 compressor wheel (known as a 2007). The K16 hybrids are most often the build up of a GT1 turbo. With the larger wheels one can sustain larger amounts of boost at the upper RPM range.

Is there anyway that you can read the ID tag on your turbo's? If you remove your inlet air pipe to your compressor housing, and get a rough measurement of your compressor wheel. I can then help you with what you have. I hope that this helps some....

By the way, the larger wheel shown supports over 600hp and 1800ft/pounds of torque.</strong><hr></blockquote>

VS

Kevin,

There is something I do not quite understand.

You stated that the raison d'etre for the billet compressor wheels is the ability to overspin. As far as I understand the overspin may result in shockwaves formation which puts a lot of
stress on the vanes. The billet wheel is stronger than the cast wheel so it has a lower risk of sustaining damage should the overspin occur. So far so good.

It would be a no-brainer if KKK just made the K16 and K24 units with this technology: same size as the stock ones but stronger. However, the new wheels are bigger than both the K16 and K24 wheels. So presumably there is no need to overspin them to achieve higher boost levels. Indeed, if the 40.56 mm stock wheel is good for 1.1 bar (am I correct ?) without the risk of overspining, the new 44.17 mm wheel should be able to genereate much higher boost just fine?

In other words, arent' the new wheels "too big" (an overkill) to be a direct replacement for K16 or even K24 stock units?

Could you please clarify this?

Thank you very much.

<img src="graemlins/icon107.gif" border="0" alt="[icon107]" />

Kevin

Globetrotter;

If one replaces his stock K16 turbochargers with the K24's without any engine modification, most individuals will report a lag. The reason is the jump in the turbine wheel size, not the larger compressor wheel size. Whenever you change the diameter of a turbine wheel it requires more exhaust to move the wheel at a given rpm, so the engine needs to run at a higher rpm to give the same about of performance. Typically in high performance applications one can dial this effect down by substituting a smaller turbine housing known as a A/R ratio. Unfortunately this can not be done with or cars.

Yes, the K24 does have a larger compressor wheel and once the turbine section of the turbocharger is spinning, the compressor side of the turbo will make more boost due to the larger wheel. It grabs more air, and with the benifit of the larger turbine wheel, the same engine will provide the user with more boost at higher RPM's.

All of this said to get to your main point, if you replace the compressor wheel on a given turbocharger, you will not incurr any lag. What you will get is more air-boost.... Another benifit of a larger compressor wheel is that the overall speed of the shaft is reduced in RPM's because the amount of boost exceeds the engines demands, which equates to most of us letting off the gas, or shifting to another gear.

KeithC2Turto

Kevin,

Do, or will, you have these wheels for the K27's??

Keith

Kevin

VS;

The K16 is the turbo that we have to worry about in the overspeed situation. When we uprate the ECU and program the ECU to ring out 1.0+ the shaft runs in an overspeed condition. We can lower this condition by increasing the diameter of the compressor wheel. These wheels can sustain an overspeed condition because of the strength. They are manufactured because there is a demand for these wheels. It's funny that the engineers could have produced any production titanium wheel, for and car. We have got it first.

VS-These wheels might seem as overkill for most people. But for alot of people they want more. By the way like you stated, the stress on the compressor wheel will actually cause the wheel to burst. This destruction will trash your engine and ruin your day.

Kevin

Keith;

There are larger wheels that will fit the K27. However, the only thing that is halfway close is the Billet K31 wheel. It is a little to big for the K27 compressor housing. You'd have to weld a larger intake inlet because the inducer is to large in diameter.

Kevin

For those who have inquired:

Here are the results on the factory maps for the various compressor wheels;

Stock K16 #2006 compressor wheel
26lbs of air @ 380cfm

Stock K24 #2007 compressor wheel
30lbs of air @ 435cfm

Titanium K24 compressor wheel
33.5lbs of air @ 479cfm

The aluminum billet forged wheel matches the titanium wheel in flow specifications.

gmonsen

hope you guys don't mind my hopping in here. i have a gt3 on order, but keep thinking about the turbo, because of my experience with my 95 rx7 turbo. like others, i upgraded my twins to larger and larger singles and went through a lot of effort to wring power from them. i swapped out the compressor from my mitsubishi turbo to a slightly larger billet wheel with 2 more vanes and had to slightly machine the snail to fit properly. i balanced the spindle and shaved the nut a bit. the result was a lot quicker spool up and more power over 7500 rpm.

does anyone offer a dual ball bearing larger turbo conversion for the 996? i think evo puts in the K26's or K27's, but didn't think these were dual ball bearing units.

finally, do any of you swap out the motronic for motec's? i have always beenm leary of the chip tuners and not being able to tune my own maps. i have a wideband lambda meter and use it to re-map my haltech whenever i change anything on my car now. i have been reading on the porsche forums and haven't seen a lot of discussion of aftermarket ecu's. -gordon