K27hf ?
 

Well, as far as I know its a K27 7006 with the larger compressor turbine wheel from some other turbo like a garrett.

There isn't a lot of information going around on these things so I was wondering if anyone had any additional information on this hybrid that they could share?

They are based on a 7200....what do you want to know I owned one for a bit

Eric Hood

I am trying to figure out what my upgrade options are since I am planning on shooting for around 600 at the crank.

Perhaps its time to concider switching to a garrett instead but I want to know what the modified K27 is good for.

The HF has a custom wheel that is 60.40mm. It is good for around 550fwhp. There are other options out there. What is your foundation to get to 600hp?

Full width 750 CI intercooler, EFI, carrera manifold, headers, super cup cams, flame rings, 7.5:1 compression. Upper limit will be 600 but I will be happy ending up anywhere in the mid to high 500s.

How will you race the car? Where is the targeted boost range? Will you ever get the desire for more hp? What headers are you running

Heh I get it

K34 or K36

Give Bill a call, we are currently building a twin turbo K 29 street engine

:eek:

Just auto-xes, DEs, and the occasional trip to the drag strip.

I would like to keep the 2500-6800 RPM 1 bar of boost I enjoyed with my K27 7006 but scramble boost on cool days might get as high as 1.4 bar.

I know I will desire more hp but between the relatively stock short block and 650 cc injectors 600 HP should be the theoretical limit.

I almost forgot, as far as headers go, I am running the following. The primary IDs are 1.5".

http://forums.pelicanparts.com/uploa...1111548919.jpg

Warning**Warning**Warning

Possible dumb question...


Whats a flame ring?

look at the bottom of my head. See the groove? the cylinders are matched with a groove as well. A variety of materials are used to make the rings. they are primarily for high boost

Eric Hoodhttp://forums.pelicanparts.com/uploa...1111549422.jpg

350...here are some turbos for you to look at http://www.precisionturbo.net/turbochargers.php

Do you have msn messenger? If you did we could exchange info more easily

Eric Hood

Wouldn't it make more sense from a top end boost and lag perspective to go the 959 route and use progressive turbos or perhaps two smaller ones (one per cylinder bank). I can't imagine one turbo spooling up quickly enough to make the car tractable if blowing 600HP worth of air into the motor...

With the exception of slightly faster spool times twin turbos are over rated.

As long as you keep the hot side of the turbo small enough its not hard to keep the engine in boost when you need it.

I will need to check the exhaust dimensions of my K27 and see what I can find in the same ball park than can stretch the limits I am looking for.

Thanks for the link Eric, that resource will prove helpful for rough sizing, and then I will be on to the maps.

Too bad my K27 needs rebuilt or I could recoup a good part of a turbo upgrade.

Precision turbo is considered at the top of the game in racing turbos. They are very helpful. I have bought my injectors from them for several years. Everything from 72's to 165lb units:) 350 you have msn messenger?

Sorry, just yahoo and aol messenger.

Turbo flange on your header is made for twin-scroll turbo.

Why not go with Garret GT-unit and be done with it? Ball bearing cartridge will make it spool even quicker. GT35 or GT40 sounds like a good candidate.

Frankly, I don't really understand why Porsche-people insist on using KKK turbochargers (some of them pretty old designs) when there are better/modern units availabe. Must be some heritage thing...

The gt35 is not available in bb you will have to go with the gt35r to get ball bearing. The gt35r is good for around 700hp. The gt35 has a smaller compressor wheel but the AR is too big for a small motor so the gt35r would be a good choice. There is a big debate going on rennlist right now between a guy introducing the gt35r to the Porsche market in a bolt on deal, and the maker of the HF. He does not believe the gt series turbo will live in an air cooled engine.

Is anyone here using the GT-35? I am curious as to where one will start generating boost on a 3.3.

The last thing I want is a motor that doesn't start making boost till 4K RPM.

There is nothing that will shorten the life of GT-series turbo "on aircooled engine" that will make it live longer on watercooled one.

Aircooled engines tolerate less EGT than watercooled ones (due to thermal constrains) so in theory, turbochargers should last longer on 911 engines that on watercooled ones (pushing 900 deg. C EGT's in certain cases). Most bigger GT's are only oilcooled so there are no water-jackets anyway.

350HP:
You cannot both have the cake and eat it. big single turbo that flows 700hp worth of air will spool later than smaller one that supports 400hp. That's the way it is.

That being said, GT-series turbochargers are present "state of the art". Big KKK's are not. It's like buying expensive Mahle pistons when there are good custom made JE's to be had for half the price just beacuse "Porsche always used Mahle's".

GT32 and GT40 are available with plain bearings. GT35 is only available as R-option and GT40 can be had in both, as far as I remember.

It's your call.

I just got this from percision gt37/40http://forums.pelicanparts.com/uploa...1111589351.jpg http://forums.pelicanparts.com/uploa...1111589382.jpg http://forums.pelicanparts.com/uploa...1111589412.jpg

Try the new K27HF2.
It is suppose to support up to 640RWHP.

My K27HF comes on around 26-2700, and is still pulling strong all the way to redline.

Brian

Brian,

Comes on around 26-2700... is that full boost or start of noticeable boost as in ~.5 bar?

thanks...

I realize that a big turbo won't spool up fast enough which is another reason why I am keeping my power limit low. I rather have a turbo that is strapped to make max boost at red line instead of one that leaves half of the RPM range virtually unusable.

Thats the reason why I was interested in the modified K27, but due to the cost and availability I am leaning beeps way of looking for the best turbo I can buy that has the right specs. The only downside will be having to modify the exhaust flange.

I spent some time today measuring all of my K27 dimensions so I can see what turbo best matches the K27 hot side since the HF shows thats its a big enough turbine. If it also has an efficient compressor that can move between 550 and 600 HP worth of air I will have found the turbo I am looking for.

Hmm, the cheap favorite of the supra guys, the T4 60-1, looks to be a rather well matched turbo to boot.

Decisions, decisions . . .

60-1 HI FI I been tell everyone for ever but of course, what do I know.

Is that what you are running Juan? Your input would be greatly appreciated.

Not anymore that was 7 Turbos ago, but even today I feel that was the best turbo I have run, she produced 545rwhp on it but that was it, after 150mph or so she will die.

Turbos are like shoes, everyone can study, read the maps etc but theres only one test, to fit it and test it with your specific application, out of 11 turbos that I have run NOT one has supported or performed like the maps had suggested and thats why it took 11 turbos to get to this level.

KKK may be good but in my eyes is old technology unless they have a new series I am not aware of.

It seems that Everyones "Lag" concerns are border line anal, is the entire combination that will give you all the juice, install the wrong headers and that can be the difference between having or losing 100hp.

What ever you do My best wishes to you and the rest of the gang in the quest for more power:)

Thank you for the input Juan. Since I am a cheap bastard it looks like 60-1 is in the lead as far as selections go.

Hey Juan, with the 60-1 do you remember at what RPMs it started to build boost?

Have you, or anyone else here, tried the GT35R?

350hp930

Gt35r wont be a good choice, like I said 37/40 w/ special trim is what I got and should be the bomb but as
juan says we wont really know until shes on the car, so we will wait and see

There is a big difference in price between the 60-1 and gt series turbos

So thats one thing you have to chose

==========================================

We are using GT35R ball bearing turbos on 3.3L 930s and the response time is great. As responsive to throttle inputs as a tiny K27-7200? No, but you can't expect any significantly larger turbo to be that snappy. It does outperform every variant of the K27 hybrid I've tried, though: K27HF, K27/29, K27/60-1... The last car we installed one onto (C2T with EFI) had 1.0bar boost <3,000rpm, and that engine had stock cams and a stock rear muffler (http://turbokraft.com/gallery/Bruce). That turbo is sized to deliver up to 620hp of airflow.

There is no reliability issue running the GT turbos "dry," without coolant through the side passages of the CHRA.

The *GT35R* does have a different exhaust flange and oil drain flange, so you have to change those on the exhaust kit you have. We can supply it with a bolt-in compressor cover.

Contact me for more information on using Garrett GT turbochargers on your Porsche 911 Turbo -