superjet.1

im looking at upgrading my turbo i have and 1987 951 i can buy a 88 turbo S turbo for $400 (kkk26\8)is this a better turbo.Whats the differance?is a kkk27 better or the same?

slevy951

My understanding is the "S" turbos are still a k26/6, but have a reworked impeller. I remember reading it in one of the Porsche service manuals.

JonM..

The Turbo S uses a K26/8. The hot housing is bigger for sure as I could see by comparing them side by side (no pics sorry). The S turbo will hold boost up to a higher RPM.

Robby

Yes, the turbo came w/the K26#6, Turbo S K26#8, and older 911's came w/K29's- I've never heard of a K28. The 951's TQ peaked @ 3500 w/HP @ 5800, while the Turbo S @ 4000 w/HP @ 6000- the turbo made ~10HP difference- the rest was the chips, which wont matter if you go to APE, Welt, Steve R, Jon M, etc...

The K27 is even larger, allowing more overall boost, and the ability to hold more to redline. There are places, like Powerhaus, that have a combination K27 #6/#8, where they have machined a part of it to fit the smaller housing or something, allowing quicker spool-up w/higher overall boost. I don't know the technical aspects, but that's the basic idea...

You might want to look around a little before paying the $400 on the K26#8. Changing the turbo is a relatively big job, and if you're paying someone to do it, the you want to make sure you are getting one that's VERY new, or rebuilt. There are lot's of places that rebuild these turbos and modify them etc. At any rate, you will still need new chips for either one to make it work optimally. Get in touch w/SFR, or someplace like that. Many places will give you a little for your turbo in exchange, but not much- every little bit helps though- right? The turbo is one place where I would not screw around- I want the best overall set-up I can get for this car, and I want everything to work together, like chips, larger injectors, etc and want to do it right the first time, b/c I can't afford to pay my mechanic multiple times to get it right...


Good luck,
Robby

Danno

Yeah, replacing the turbo is like an 7-10 hour job. Definitely get a warrantee of some sort on that turbo. Maybe even nibble for some of the labor costs if you have to pull it out later...

superjet.1

im gonna do the work myself and the turbo is rebuildt.but should i hold off till i can afford k27\6 or will the k 26\8 be a good thing for a non track car.

Danno

I would hold off and get one of SFR's Garrett turbos if you're going to be putting that kind of labor in. I think they're around $1000 or so. Definitely worth the price because a K26/8 is marginally better than a K26/6 at best. When you start bumping up the boost to 15psi like the Autothority kits, the difference gets even smaller with both of them running out of steam well before redline:

87 944T vs. 89 944T TQ (both with APE chips)

Robby

I have to agree w/Danno- if you're going to go through the trouble, at least find a K27 or something that can hold the boost better- there are a lot of turbos out there- maybe you should start a thread on what people are using and how they like them- spool up, overall power, price, etc... I've been planning this, but it's going to be awhile before I can do it anyway, so I don't want to waste the time yet- hopefully, by the time I get around to doing the mod, there will be a few more people who have done larger turbos, like the SFR's and such to give me some insight...

Robby...who doesn't want to be a guinea pig...

Chris Prack

I wouldn't bother with a KKK turbo as an "upgrade". The design of these turbo's is from the '70's. They are very inefficient by today's standards, it would be about the same as using CIS as an upgrade to EFI, you just wouldn't do it.

A Garrett would be an excellant choice. Try Kokeln for a turbo, they have some nice units. I havn't seen anything from SFR but if it's Garrett then see what they have. Spend your money on a good turbo.

Luke

[quote]Originally posted by Danno:
<strong>I would hold off and get one of SFR's Garrett turbos if you're going to be putting that kind of labor in. </strong><hr></blockquote> [quote]Originally posted by Chris Prack:
<strong> Try Kokeln for a turbo, they have some nice units. I havn't seen anything from SFR but if it's Garrett then see what they have. Spend your money on a good turbo.</strong><hr></blockquote>

WEll,If you've seen a Kokeln, You've basically seen an SFR. They are Both Turobnetic turbos. I would highly reccomend them. And since SFR has the lower price, I would reccomend SFR




I'll have dyno #'s in about a week or so on my 54mm comp wheel stage 3 turbine #6 hothousing level 1 SFR turbo.

Luke

[quote]Originally posted by Chris Prack:
<strong>I wouldn't bother with a KKK turbo as an "upgrade". The design of these turbo's is from the '70's. </strong><hr></blockquote>

I wouldn't totally agree w/ this. Audi volkswagon and porsche still use kkk items for a reason. Besides, there is alot of technology from the 70's (turbo charger wise) that hasn't really even been adapted to the garrets. There is alot of stuff out there but I have seen many k27/6's that make 330 @ the wheels. That's ungodly powerful. And that is a #6! I have taken apart my k26/6 and compared it with my SFR. The comp. wheel and turbine look identical in design. Im pretty sure the biggest difference in the two is meterials and size. There is nothing wrong with kkk. My 26/6 lasted 16 years and there is NO bearing play at all!

Tabor

VAG and Porsche still use KKK because they are German. Same reason they used the POS VDO guages that are in our cars.

Luke

[quote]Originally posted by Tabor Kelly:
<strong>VAG and Porsche still use KKK because they are German. </strong><hr></blockquote>

Well, it may be German, but that by no means makes it bad!?! And this German idea does'nt explain why Porsche used Mitsubishi Balance shaft designs.

Chris Prack

I wasn't trying to say that KKK is junk, they are just not as efficient as the newer turbo's that are available today. Hell, I still have the OE KKK on my car and it does just fine. Were I to want or need to replace it, I would install a better turbo. If you are happy with the 3K then have at it but I know I can make more power at a given boost level with something else, BTDT.

Luke

A comparably sized garret will perform VERY similarly to a k27. My k26/6 made full boost at 2.800rpm and held 16lbs to redline!