Josh B

I've got this k27/6 that came of that silver rose with the body issues and scored block. The PO advertised that it was a k27/8 but it looks to me to be a 6 in the opening of the hot side. On the label it says Powerhaus k27 #7200 June 1997. I think it probably needs be rebuilt as it has some back and forth shaft play and up and down as well. I noticed on the Lindsey page that they will rebuild a turbo for $375.

Do you think that I could find a better turbo that still had some life in it for around $500? Is the K27/6 a really good turbo? More importantly with a 38mm Tial wastegate/Autothority MAF/65lb injectors/3 inch exhuast - no kitty/worked head and this turbo can I get low 300 rear wheel horsepower at 15 PSI?

anders44

its 20-30yo technology.. imho not worth very much seeing as you can get ballbearing GT turbos theese days.

Josh B

Hmm - so the turbo that this guy is selling would be a better option?

http://forums.pelicanparts.com/showthread.php?t=366088

Here is a pic of my engine bay - am planning on posting a thread a little later of the whole car and what I have done to it so far...

Porschefile

K27/6's work and do make more power than stock, however that hotside and turbine are so ridiculously small it really isn't even funny (in the Garrett world that's practically T25 stuff which is lame for a 2.5l). If you want to keep things cheap and don't mind some custom work. Get a typical Garrett T3/T4 or Precision SC series turbo (same stuff, Garrett-based) with the 4 bolt T3 hotside (.63a/r or .82a/r are the best 2 options). Technically the downpipe bolts right on (same bolt pattern as a K26), chop the KKK flange off the crossover and modify it plus weld on a T3 flange and you are practically done for potentially under $800. There's a bit more work involved than that of course, but just a thought. Other than that and maybe finding some other bolt-on used turbo from someone, LR's Super 48 at $1099 is about the next step up and should be a pretty decent turbo (search this forum, there has been some info posted on it).

special tool

The problem is that most 951 guys believe they are making an honest compromise.
Well, that is not the case.
A #6 K26 turbine/housing is soo small and soo inefficient that you sacrifice BOTH top end power AND spoolup.
The k26 family, EVEN THOUGH IT IS SO TINY, DOES NOT! SPOOL UP THE BEST ON THE 951.
That is to say - you get the worst of both worlds.
You get huge torque dropoff and adequate (at best) spoolup characteristics.

My comments are meant to be taken in comparison to modern hybrids.
I have had 7 turbochargers on my own 951 and have tested and tuned many others.
The best all around turbos I had were the Vitesse hybrids - that's just the way it is.

The only good thing to be said about the k26's is that they are very tough.

George D

Porschefile is giving good advise here. The K27/6 stuff is based on 20+year old technology. I used this turbo 15 years ago and it was a good unit.

A good used turbo for your car is out there if you do some digging. I recently sold a LR super 75 for $300. It had a little damage to the wheel, but had no other issues and would have bolted right up and ran for years. A new wheel is cheap and the bearings and such was fine. I would go with a smaller turbo on a 2.5 though. I only had 430whp using a turbo that would flow 600. This turbo came with the car. 400whp doesn't require such aggravating LAG.

Call some of the tuners. They sometimes get good turbos when installing their new turbos. If you can find a really good K27/6 for $100 and you are doing your own install you'll get your money's worth. If you are paying labor, do it right and take Porschefile's advise.

For 300whp there are MUCH better turbos than the K27/6. You will love the spool of the newer stuff at this HP level.

George

hosrom_951

That appears to be a #6 hotside, due to the 'squares' on the sides of the hotside (the #8 is circular all round), look at Clarks website for the difference.

Hey, if you are happy with the K27/6, then just rebuild it (Bob is great, www.turbo-performance.com), if you are looking for upgrades, you have opened a whole new chapter.

Porschefile

Thanks ST. I'm glad that someone respected here agrees. It's what I've been trying to say forever. After physically seeing #6, #8, #10 K26 housings as well as some K27 housings in comparison to Garrett T3 and T4 stuff, I was shocked at how small K26's are. They are most similar to T25's, and K27 hotsides are in the T3 frame territory. Anyways, after seeing all of that, I came to a realization that T3 .63a/r and .82a/r housings are the perfect "compromise" that's really missing with the 951 aftermarket. I wish someone (hint hint LR, VR, SFR please do it!) would market some simple conversion components to allow an easy bolt-on solution for T3 frame turbos, it would open up a huge section of the market. Right now you have retailers cramming stuff like massive 67mm T4 compressor wheels (the LR S75) and large stage 5 turbines in insanely small housings to try and pump out decent numbers. In the end you end up with a turbo that is so restricted you have to use massive over-sized wheels to try and make up for the restriction. There are just so many better ways to do it. The bolt-on stuff for these cars works obviously and there are plenty of options out there. Though, there is a worthwhile amount of extra power, torque, improved top-end curve, and better spool to be had on motors of this displacement with typical T3 framed stuff as opposed to the typical bolt-on stuff available right now. K26 hotsides are too small above ~300whp (oh they work but are so restrictive its a joke), then the next bolt-on step up is several vendor's T4 setups. T4 hotsides are joke on 4 cylinders under ~650whp. Basically what I'm trying to say is there is this 300-600whp gray area that has a substantial amount of room for improvement that really has yet to be addressed from the vendor side in this community.

Josh B, sorry not trying to hijack your thread! I think the question we should ask is are you looking for a simple bolt-on upgrade, or do you not mind doing a bunch of custom work? If you want something bolt-on and simple, I'd see if LR will do a Super 48 with a #10 hotside and stage 3 turbine. That would be a responsive turbo and should get you around ~300whp on ~14-16psi. Their new Super53 turbo COULD be a good one in combination with a #10 hotside and stage 3 turbine. They kind of screwed it up a bit though as it comes with a stage 5, and stage 5 turbines are pretty much unnecessary under 500whp as it just equates to unnecessary lag for just a bit more power. If you don't mind some custom work, a 50 trim T3/T4 w/ stage 3 turbine and .63a/r hotside would be a sweet little turbo for the 300-400whp area and would still be VERY responsive on a 2.5l. The journal bearing t3/t4's are pretty cheap (usually ~$600-800), though you can also now get them in ball bearing if you so desire.

All of this aside, just rebuilding that 27/6 would be the cheapest and easiest route, would get you to the low 300's like you want, and would still work just fine. The only point I'm trying to get across is there are a ton of better and more efficient turbo options available to you if you really want something better. At the end of the day, whatever works and whatever makes you happy is all that matters.

schwank

Damn.... thanks to reading this thread and a couple others, I ordered Corky Bell's book on turbocharging today. I don't know squat!

Rogue_Ant

I like my K27. I've made decent power out of it, and get 15psi by 3000rpm (datalogged). However it leaves some to be desired. Transient response is sluggish, and I'm at the limit for power output. I will eventually go to something different. But this turbo has been a lot of fun, and hurt a lot of muscle-car guys feelings.


Rogue

TRP951

My vitesse turbo makes awesome power and even with a #10 housing im getting 1bar by 3400rpm.

special tool

Be careful with that antique book - I am sure even he has changed some of his opinions in that book based on the passing of almost 20 years.

See "water injection", for instance.
Also - "high boost applications"....at over 1bar.
Quaint.

Josh B

Hmm - interesting discussion. I really appreciate all the info! Seems like what I am hearing is that if I ONLY want low 300s then the cheapest route is probably to rebuild the k27. However with the other upgrades I already have on the car and since I can do a lot of my own work (aside from fabbing up a modded crossover) it would be a SHAME not to invest a little more money in the car and realize more potential Maybe my plan will be to drive it as it with the stock 26/6 and lay for one of the above recommended turbos.....

ivai

Vitesse FTW!!! Car looks nice Josh.

RolexNJ

Now you got it. That said, try the magical pixey dust turbo that Vitesse makes. Once you get one, you'll never want to look back again, trust me. And I'm speaking from my personal experience, with tons of datalog sheets, and other people I know too!