kellcats521

Need opinions on using this on a mostly stock '87 3.3 motor? I've been told that this will spool up faster than the K27 7200 while keeping the top end of the 7006.

Any insight??

Thanks,
Pat K

WERK-I

Hi Pat,
I have a 7006 in my 930 and by the time it gets up to 5000 RPM, it has pretty much given up the ship. I have a twin-plug, SC WebCams, Kokeln IC, B&B headered 3.3l engine. I believe I need something that will flow 450-500bhp and the 7006 just doesn't cut it.
Hope my $.02 opinion helps guide you.

Dave
'85 Factory Slantnose 930

PorschePhD

Very old technology. The K27 will die off and stop making power up top. This is why the Hyflow was made as well as the K27S. Both of these utilize new technology and not reused wheels of the past.

Sameer

Pat,
Stephen is correct. The K27HF spools quicker than the K29 and flows more air than it too. The stock K27 is no where in comparison.

Kevin

As Dave has mentioned that describes a normal 7006 with a 11A/R housing, if you install a 9A/R housing you tighten the A/R even more. Yes, it will spool up quicker but it will die even faster..

Stephen has mentioned the benifits of the newer designs..

kellcats521

Let's back up a bit.....
This is a stock, CIS motor. Being able to move air for 450-500 hp is not relevent. I only need to move 10-15% more than stock, and move it more efficiently that the stock unit.

I'm only looking to improve on the 3LDZ unit that I just removed. I have a 700hp track car that scratches the go-real-fast itch.

I've build more pressure fed and n/a motors than I'd like to remember. Big housings and wheels = slow moving air = lag..... I really doubt a 7006 is not enough turbo for a stock 3.3 motor - although wheel designs may be more efficient today, I'm pretty confident that Porsche didn't 'choke' the 930S motor with a 7006.

Pat K

Kevin

Yes, but the 9 A/R will choke the engine. If you use the same "term and conditions" Porsche went to the 7200 for the 965's.. The 7006 is not a wise choice. The 7200 "S" or Hyflow are much better designs. The 7006 with a 11 A/R and larger turbine wheel can't get out of it's way on a stock 3.3ltr engine. The 7200 design is in reverse of the 7006.. Smaller turbine wheel, large compressor wheel.. (7006, large turbine wheel, very small compressor wheel)..

kellcats521

I must be missing something here.....

The 'stock' 3.6 965 ran the K27 7200 and produced ~360hp. The X88 optioned 1994 3.6 930 Sport ran the 7006 and produced 385hp, but the 7006 turbo is not as good a design as the 7200???? My understanding of the 7006 is that it is better than the 7200 in the upper RPM ranges at the expense of some lag.

A local authority on Turbo 3.3's uses the 7006 with a tighter housing to speed up flow and reduce lag - they claim that a street driven CIS motor cannot move enough air to make this turbo the weak link. I'm sure there are many options that work, but the data from Porsche seems to support their claim.

Pat K

Kevin

Pat the 7006 with or without a 9 A/R is a dog.. The 7006 will not put out enough air due to the small compressor wheel. The application of the 7006 worked on the 3.6 because of the larger displacement. It was able to spin the larger turbine wheel. However, the compressor wheel was very inefficient and at 5200 RPM, the wheel is done.. Pumping hot air into the intercooler is the result.

The new compressor wheel designs and housing choices today leave the 7006 as a 2nd choice. I have compared all the turbochargers that you have mentioned, I see them everyday.

WERK-I

Pat,
I never said the 7006 wasn't suitable for the 930S from the factory, but that was twenty years ago. Let's put everything in perspective here, the 930S engine(330bhp) came with SC cams and a better turbo(7006) than the 3LDZ boat anchor. But, I have upped the VE of the engine, bigger more efficient IC(denser air charge, more aggressive cam profile(longer duration) and B&B headers(shorter primary tubes, higher gas velocity/temperatures).
When I drove the car before the mods, the 7006 seemed perfectly suited for the car. Now.......no way.

Dave
'85 Factory Slantnose 930

kellcats521

Dave,
I'm in total agreement with your assessment of your car - the modifications you've done will allow for more airflow than the 7006 can deliver. I'm sure it seems as though your car is running out of breath now, and it appears that you've got the fuel system and cams to support more airflow. A turbo with higher flow capability would work on your car. I agree that a highflow design using the K27 architecture should produce close to the same airflow (and therefore general hp numbers) as a K29 (which is a huge unit) without the BIG turbo lag that the K29 has.

With my car, I'm not planning on replacing the CIS setup, so I want to simply get the most from what I have. Bolting a blower on my car that will move 500+ hp worth of air without the cams and fuel system to actually use that air won't work in any other engine so I can't see how it would work in a Porsche.

Pat

WERK-I

Hi Pat,
Thanks for clarifying. The only thing I can add to the upgrade of a newer turbo system is the newer impeller and turbine wheels are machined to tighter tolerances and somewhat improved in their design. CNC is a magical and wonderful thing! So you might get a more efficient, quicker spooling turbocharger with the newer iterations. I'm not promoting anybody's turbo.....I've yet to upgrade mine! Maybe over the winter, budget allowing, of course.
Good luck in your project.

Dave
'85 Factory Slantnose 930

Win Rice

Sounds like you need a K27S.

Be carefull with the "Local Authority". There are plenty of street driven CIS cars that make full use of a K27HF. Stephen and Kevin are two of the top Porsche Turbo Authorities in the country, learn from them.

Win

DonE

The only turbo that really worked on my CIS car was the K27HF. Based on dyno runs, here is what I found: stock K27 7200 fell off at 5400 rpm (325 rwhp); Kokeln spooled too late, 1.0 bar at about 4400 rpm (370 rwhp); TPC hybrid spooled too late(about 4400 rpm) and fell apart after 1 year(410 rwhp). The K27HF spooled well (about 3800 with my mods) and held 1 bar to 7000 rpm(400 rwhp). Equally as important than all out HP was the torque curve on the HF - almost as early as the stock K27, but much more agressive and more of it. For the price and its architecture, I think its one of the best turbos for a CIS car - it will compliment any mod you can do to a CIS car. Nope, didn't get paid for this either...