mrfixit951

J chen,

I have not seen a dyno plot of a K27/6 that can maintain 325-350 ft-lbs or torque up to 6500. This equates to around 340-370 RWHP.

It has been shown that a K27/8 can do this, and a K27/6 can reach 340 RWHP but the torque drops off dramatically at upper RPMs.

I have a K26/6 turbo that needs a rebuild. At this point a K27 conversion will cost at least $550, and still have the -6 hotside. For more money I can find a scrap K26/8 to create a K27/8. Both will need to run higher boost, and be require more octane than a new Garrett turbo.

Because I have a TIG welder and do my own work, I have decided to forgo the price of the rebuild or K27 upgrade and use this money towards a state of the art turbo (even Tony G eventually did this). My project budget does not allow me to spend $1200 on just the turbo.

Yes I could buy a TEC Ni Resist T04E 46 trim with a -8 hotside for ~$900. Looking at its map it still ends up left of the surge line at 20psi boost (like the GT32 compressor). The super 50 that Rage had does not and does look like a great turbo.

The compressor blade and housing of a GTXX71 can be bolted to a GT32 turbo. Creating a journal bearing version of the GT3271. Both having T3 style turbine housings.

Ben

J Chen

How on earth can the TO4E 46 trim end
up on the left side of the surge line while
the super 50 being a bigger wheel does
not. In general surge occurs when you fit
too big a compressor wheel to a particular
engine size. I do to think the the super 50
is a good choice. Since you're handy with
TIG, can I give you a suggestion ?
Go with a TO4E Super 50 with stage III
turbine trim but specify a T3 housing in
0.64 AR. If i'm not mistaken it's also available
in .48 AR. Why, I understand that they flow
better than the KKK hot housing. I think you
can buy one for about 700-800 USD.

Dark Lightning

Do you have links for these? Thanks.

Corleone

Thanks!

mrfixit951

Dark Lightning

Check out www.turboengineering.com, a cpt_koolbeenz bought one from them last year. I have never dealt with them, many others have. Maybe someone with first hand experience can chime in?

J Chen,
I mispoke on the 46 trim, it was the 50 (non super) that appears to be slightly left of the surge line at around a 2.5-2.6 pressure ratio. It may not depending on the VE and efficiencies that you use.

Within the price range you just listed I can purchase a brandnew GT32 non ball bearing center section and turbine wheel, GTXX71 compressor wheel + housing (check out Edman951's map of this) and a T3 turbine housing in my choice of A/R. To each his own, and to me this seems like a better solution than an T3/T4 hybrid or a K27/X.

Ben

Edman951

The GT3071R is not a off the shelf Garrett turbo.
ATP & Garrett have teamed up to build custom turbo for the aftermarket.
ATP is one of Garrett engineering houses & performance houses.
ATP is working with Garrett engineer to come out with new turbo's to better fit the high HP small displacement motors we see on the market.
The GT3071R was actually built to make a 450hp Mitsubishi EVO8.
You can read about it on ATP website.
They say that on the EVO8 with the GT3071R spools up 300-400rpm later then the factory turbo.
Read about it here
http://www.atpturbo.com/root/releases/release052704.htm

When it comes to turbo.
Like Ben said "To each is own"
You can buy them from the tuner bolt-on or you can custom fit the one you feel will work best for you.

And like JChen said,
it's alot of work to fit a GT turbo on a 951.
While i was doing my install i got thinking that a turbo from SFR or Vitesse would have been alot faster and easyer.
But know that i have it all done and paid for. I don'T think about the $$$.
I really like my GT30R.

So Ben, if you want to go with the GT32 NBB go for it.
I hope you get some good power out of it.

Edman951

My GT30R exact spec are
Compressor wheel: inducer 2.24/ major 3.00" (76mm) 56 trim
Compressor housing GT,T04E size 0.60 A/R 4'' inlet ported shroud
turbine wheel: 2.16/ 2.36" 84 trim
Turbine housing 0.63 A/R GT 4 hole 2-1/2'' outlet (same bolt patern as KKK)
T3 inlet flange.
Power range from 350 to 550hp

Pauerman

JChen,

For the GT30XXR turbos, how do you think these medium frame turbos with T3 series turbine housings compare to the KKK turbine sizes?

eg - .63 a/r T3 equal to 8 cm2 KKKor .82 a/r T3 equal to 10 cm2 KKK

Are these accurate comparisons of size?

Andrew Wojteczko

Edman,

The turbo you are using uses the Compressor listed in the Garrett catalogue for the standard GT30R. When I plotted this map I was crossing the surge line at 4000 RPM, how did your plots work out? Have you experienced any surge? We are looking to make 400 at the wheels, are running 83lb/hr injectors and TEC3R engine management (thanks to tim at SFR). I used 80% VE for the calculations, here are my points:

RPM CMF
3000 15.51
4000 18.09
5000 20.68
6000 28.43
7000 36.19

It looks great between 18-22 PSI at 7000, it's in the peak efficiency, but I am concerned about crossing the surge line.
I see the 3071R plot does not cross the surge at all, what were your deciding factors to go for the 76 mm wheel VS. the 71mm wheel.

Thanks

Andrew Wojteczko

Andrew Wojteczko

One other quick quesiton, has any one established any data as to the exhaust manifold pressure, before and after the turbo so the calculations could be performed to use the turbine maps?

Thanks again

J Chen

Hi Pauerman,
My .82AR hot housing is about the same size
as the KKK26/6 & this is a T25 model. I think
a .48 & .63 AR is a more valid comparison in
the T3 range.

NZ951

I have the #8 hotside and I dont think the hotside AR would be more than .82. As it is that is quite large I dont think the #6 would be that high... surely!???

J Chen

NZ,
Sorry I down understand your statement.
Please clarify

J Chen

Hi Pauerman,
Sorry, I misread your thread. Yes I think
your camparison is valid but I suspect
you'll end up slightly larger or smaller
when compared to the KKK 8 & 10 hot
housing. What do you have in mind ?
Basically it's very hard to just compare
physical dimensions alone on a turbo
cause there's so many other variables
involved. Example my GT25TO4S though
spec says that it can make 450hp. I'm
not so sure about that why ? Yes the
compressor will flow that much air but
it's team up with such a small turbine &
it makes me wonder if the turbine can
generate the power to produces that
kind of hp. I've not finish tuning yet so
for know I console myself by knowing
that it's a standard GT issue from Garrett.
So it can't be a fake claim.

Duke

J Chen, NZ is talking about the equivalent T3-A/R size for the KKK 8# hotside.
IIRC the 8# hotside is more similar to a .48 than a .63 T3 hotside.