26/6 to 27/6 upgrade experiances?
 

Hi, looking for feedback if you've done the upgrade above. My objectives are the following:

- plan to run about 15 to 16 PSI max / pump gas
- looking to maintain boost to redline vs. current falloff
- want to have no to very minimum change in low RPM spool and boost points
- car is used for HPDE / track days and street

Current car setup is this:

- stock motor
- tial 38mm
- SciVision MAF
- 3" SFR and cat delete
- 3 bar FPR
- maxHP chips (would need to be changed)

Feedback on the before / after with the points above and amount of custom effort beyond bolt on for installation appreciated.

thx!

Jeff

Jeff,
Here is a couple of threads with good info:

K27 info
J-Boot for K27


-Rogue

Thanks Josh - great info. Anyone have anything else to add? Love to hear more first hand experiances.

My setup is:

Stock motor
K27/6 7200
Vitesse MAF & Software
55# injectors
Tial 38mm
3 bar FPR
Stock exhaust w/Cat bypass
MBC

I've found this to be a solid upgrade. I run 15 psi and it holds boost to redline no problem. Spool up is ~300rpm later than the K26/6. I find this setup to be much more linear than the k26/6, which tended to come on boost hard and then taper off. I've done several DE's and have found it easy to modulate at the onset of boost, I just haven't had any of those "nothing...nothing...BOOST!" moments.

It's a pretty straightforward bolt up from an installation perspective, I just had to bend the water pipe a little and that was it. Well, other than the joy of removing and replacing the turbo...

HTH

Search for TonyG k27/6...

It's been hashed out over & over & over & over again...

Good luck, have fun and be ready to open your wallet

Thanks Greg. Good feedback on how the car performance changes relative to the boost.

What might setup like this dyno at?

LOL, I should have followed Rogue's thread first since it already had a bunch of input from me.

I haven't been to the dyno so I can't say for sure. Based on my research of others with similar setups it looked like ~300hp at the wheels +/- 20hp. Again, though that's not first hand experience.

Yep - I actually searched your name, because I knew you put out a good review ;)

And I agree with your hp estimate as well.


-Rogue

Yowza. 300WHP!

I think I might have to pull the tigger on this. I have a local contact who's got a rebuildable 27/6 and it looks like I have most of the other parts are more or less on the car. Would just need to work thru the J-boot setup and move over from the airbox to a cold air setup.

Ask if it comes with modified coolant pipe. I went to a welder yesterday and modified mine, since it would not clear the compressor housing.

I had a completely modified KKK27/6 ( see below for details ) and I got 348hp @ 5568rpm and 506Nm ( = 375lb-ft ) @ 4056rpm ( both at flywheel ).

KKK27/6 hybrid,compressor housing K27/3LEP with 52x76mm Holset wheel ,turbine housing original /6 with KKK 62,5mm wheel modified to 60x66mm ,A/R 0,6 .
Exhaust: Full 3",including downpipe, cat installed. Stock airbox with K&N, GURU map kit.

I once installed an additional boost gauge with a hose to my crossover test pipe and made some test accelerations. Result: Boost 1,2 bar, pressure at x-over 1,8 bar at 6000rpm. Ratio 1:1,5. This was also confirmed in the dyno, raising boost above 1,2 bar did not increase power, just increased back pressure.

Spool was almost like stock, 1 bar around 3,3k. That modification cost me €850,- , at that time it meant arount 1-1,1k$. Required modifications to hardware were J-pipe and coolant pipe. instructions for both can be found here, but I have one recommendation for that coolant pipe: Cut the pipe above banjo in two, install a pipe of larger diameter and required length around original pipes and weld / hard solder the parts together. A shop should charge for that like $10-50.

IMO this 27/6 is worth money wise, cost should be less than $ 1500 total, around $1000 if you can do all the work yourself, the most expensive part being that new or your old, modified turbo. It gives well enough( usable ) power for DE's and auto-X.

pete
That right there is why I have wondered why every so insists on running such small hotsides

300 to 350 HP max IMO otherwise use a larger unit

I am obviously happy with the k27/6, it's an economical way to go for a street driven car and the installation is pretty straightforward. It performs like I expected it to and is a nice upgrade over stock.

All that said, I now wish I had saved my pennies and just gone straight to a Vitesse Stage 2 or 3. Why? Because I think the car is capable of even more, John continues to add cool new features and we're never satisfied with how many HP we have, right? I'd like to experiment with E85 but between the K27/6 maxing out at ~17psi and the limitations of the 55# injectors I installed it's just not really possible. Plus I'm not looking forward to doing another turbo install.

So why didn't I go that route initially? It all comes down to how much you want to spend. But, like many upgrades, if you think you're going to ultimately go whole hog you're better off financially just waiting until you can do what you really want to rather than pay twice, once for the less expensive compromise solution and then again for the thing you really wanted.

None of this diatribe is intended to put anyone off the K27/6, just food for thought before you plunk down money for any upgrade.

I've had two K27/6 variant turbos on a past 951. The first K27/6 was from PowerHaus with similar mods to your car. With a very good chip tune it spools as well as a K26/6 and better than a k26/8. This was my favorite turbo for a street driven 951 with minor bolt up parts to accomodate the necessary parts to allow it to work properly.

My blue 89 951 was fairly stock. Just enough parts to make the K27/6 turbo work properly. We had a very good tune and at Technodyne we hit 330hp at about 6200rpm and 340tq by 3500rpm. This setup was my favorite upgrade for a basically stock 951. Immediate boost, held 18psi to redline, and was a fairly straightforward install.

There are many variants out there. Use a good turbo vendor. If you buy one used, have it inspected and rebuilt. You may get lucky on a good used turbo, but be careful. I sold one for 400 bucks and I think it's still boosting at one bar out there with about 120K

Best upgrade for the cost.

George

Thanks George. Is your experiance with the "7200" variation or the "7006" variation? I'm getting lots of feedback that the 7200 is the one to go for and to avoid the 7006. Seems to be quite a few 7006's available but not so many 7200's.

Forum rules keep me from asking for a 7200; I may have to finally pony up the member fee. :D