Crackership

I'm sure someone had asked this question before, but I can't seem to find a definitive answer...

The K27 was used on quite a few different cars and, for some reason, every K27 I find on eBay is for something other than a 951... so the question is, are they interchangeable? I kind of doubt it, but I figured I'd ask.

onspeed

maybe because the 951 never came with a k27?

Crackership

Educate me if I'm wrong, but I was pretty sure that a turbo s came with a k27/8

Jeremy Himsel

Nope, only the26/8 on the 951(s).

onspeed

K26/8 in the 88 Turbo S and 89 Turbo

K26/6 in everything else

The 930 used the K27 I think.

Crackership

Ok, apparently I was incorrect... so am I delirious, or do people commonly put k27s on 951s? And if so, which k27 do people use?

Scott H

The K27 you want is the 7200 series wheel, the earlier 3LDZ and 7006 wheels are less efficient. It was used on late model 964 Turbos. Do some searches for K27 7200 and you'll find some good information. You only need the compressor side, everything else is useless to us.

You'll be keeping the K26 turbine, turbine housing (whether #6 or #8), CHRA, but replace the compressor housing, compressor wheel and backplate.

onspeed

It's a common upgrade. Cheap, reliable, makes power. But you usually won't see one listed on EBay for a 951 because the ones we use are hybrids. As said above, k26 turbine, k27 compressor.

Crackership

Ok, thanks for the info. Next question: does the k27 flow significantly better? I've heard from several sources that anything more than about 15-16 psi on a #6 hotside will result in dangerously high back pressure, so will running, say, 15psi on a k27/6 net a substantially higher rwhp number than a k26/6 at 15psi?

Mighty Shilling

I'm putting a K27/hybrid in this weekend. They should bolt right up. I have never heard of the backpressure issue, but I'm not anticipating a problem because I have a bored out #6 housing that I put a #8 wheel in.

onspeed

I usually see dyno charts near 300 rwhp with the 27/6. Compared to 260ish with 26/6. The 26 falls on its face at higher rpm and by redline you're usually only getting about 11-12 psi. 27/6 does not.

Olli Snellman

And here in europe we got 951's also for model years 1990 & 91

930 used K27.

Here's a 26/6 i just had modified. The current configuration contains 27 compressor housing and enlarged 6 turbine housing. Internal parts are mainly from Garret & Holset

Voith

Olli, can you post picture of turbine wheel?

What is the size of hot side wheel on #6 turbine? (#8 is +/- 6cm)

Olli Snellman

Size is between #6 & #7. Turbo is heavily modified, more or less only center section is orignal. This turbo was modifed for a Swiss customer.

Voith

so this is true 6 than.. :/ I somehow hoped its 8 wheel in 6 housing (hot side)

https://rennlist.com/forums/for-sale...7-8-turbo.html