I killed my turbo!

[Mihnea]

@Gandalf: good AFRs can sometimes mean VERY BAD EGTs!!!!! how can a tuner get good AFRs but not measure EGTs??? FFS!!!

Anyway, I hope your engine is ok and that it's gonna be even faster with the new turbo

[GandalfS6]

Thanks Minhea! I am running water injection so I doubt that the EGT's were too high but you are right - it must be checked! I guess I have to get a EGT gauge!

BTW what do you think of the turbo choice?

[Mihnea]

Hmmm, I've never heard of anyone, nor have I ever thought of running a super 46 trim T04E compressor on a 2.2 20vt... got a compressor map for it?

Cheers,

Mihnea

[Billman]

@Mihnea
I think that is the compressor map!

We are wainting for your opinion!

For what does the super stands for?

[Mihnea]

Hmmm, not as good as an RS2 unit at the low end of the range (should surge with 1.8 Bar boost at 3000 RPM, never mind below that), and can't hold more than 1.6 Bar at 6000 otherwise the thing will overspin like nuts. Should be good for 410-420-ish when pushed, but IMHO still a poor choice.

The best choice so far for a 20vt from Garrett/turbonetics is the T04E 50trim or the super 50 trim, stage 5 turbine and #8 hot side with single ceramic bearing or dual ball bearings (noisy). Great turbo for 450-ish HP, lots of low-end torque and awesome spool-up!!!!

HTH,

Mihnea

[GandalfS6]

Thanks again Minhea! It is not too late for me to change to a 50 trim - will discuss with the guy I got the turbo from. Unfortunately, I am waiting for parts and a check up of the engine so I have a bit of time!

Just a stupid question - will a 46 trim not spool up and get to boost faster than a 50 trim?

[Billman]

@Mihnea

What about this turbo?

Garrett TA34/TO4E 57 trim hybrid ? I think it can be used with the Rs2 Turbine housing! They use a lot in the US.

What specs should this Trim 50 turbo you mentioned have and what about the durability of the ball bearings?

What do you think about the k26/27/29 8" that is used very often in germany?

Sorry for the many questions

[GandalfS6]

Looking at the compressor maps of the Super 46 and the Super 50, the Super 50 looks much better! Pretty close to the RS2 at the bottom end but can run much more boost top end. Back to the drawing board?

[Billman]

This is going a little too far but can the VTG (Variable Turbine Geometry) from KKK used in a Hybrid K26 turbo? This is for big diesels like the k26-k27 ect turbos!

[GandalfS6]

I spoke to the guy who supplied my turbo today. The full details of the turbo are:

Turbonetics compresser housing with a 0.70 AR
T04E Super 46 Trim compressor wheel
Stage 3 T3 turbine wheel
KKK K26 # 26 turbine housing with 0.63 AR
Single ceramic ball bearing
Turbonetics thick shaft (apparently very robust)

He tells me he recommended the 46 trim over the 50 trim as I need quick spool up and only 420 hp. We also have to take into account that we are at an altitude of 5000 feet (standard barometric pressure of only 850 mBar) and that means that turbos spool in on average 500 rpm later than at sea level. This implies that one would probably chosse different turbos up here than one would at sea level. His philosophy is that one has to give up hp at this altitude if you want decent spool up. He is quite happy that we change to a 50 trim later but suggest I try this setup first. Oh also he said the fact that I use water injection needs to be taken into account when choosing a turbo.


Also, he believes that the turbo with the thick shaft and roller bearing is strong enough to run without a diverter valve. I know that is what the rally Quattro's did. He can't however give me a guarantee that the tubo won't break if i do that but I will probably give it go for a few laps!

Any comments? All this turbo stuff has me pretty confused ....

[Mihnea]

Huh? What??? is that guy a tuner or a DIYer??? No diverter valve??? WTF is wrong with having a diverter valve in his opinion????? No DV will mean lots more lag, WTF?????

Plus, IMHO a 50 trim runs great at altitude. A car that I've tuned in the US with a 50 trim produced 387 HP at the wheels (corrected).


Hmmm, gandalf, can you give more details on how this guy tunes your car??? i.e. how he actually modifies the chips? Does he simply program chips and goes with you for test drives and so on?

Mihnea

[GandalfS6]

Mihnea, the guy imports Garrett and Turbonetics. According to him the Subarus are 2 seconds faster around a 1:15 track if they run without a DV. Geoff Mortimer who does some mechanical work on my car told me the sound that the Quattro rally cars made was "air shear" as the Quattro's ran without DV's. According to the Garrett guy, the turbo stalls but you keep the boost up if you don't use a DV.

My tuner is a different guy - Frieling Racing in Germany has a guy who does tuning here. If you replied to my PM's it could have been MRC You did a stunning job on Shane's car (which I had the pleasure of driving).

[Billman]

@Mihnea

What about this turbo?

Garrett TA34/TO4E 57 trim hybrid ? I think it can be used with the Rs2 Turbine housing! They use a lot in the US.

What specs should this Trim 50 turbo you mentioned have and what about the durability of the ball bearings?

What do you think about the k26/27/29 8" that is used very often in germany?

This is going a little too far but can the VTG (Variable Turbine Geometry) from KKK used in a Hybrid K26 turbo?

Sorry for the many questions

Thanks a lot

[S2 Ant]

Surely by removing the DV the pressure backs up and as you say, stalls the turbo, it can only spin so much and will then just slow down, with a DV the air continues to flow so the turbo doesnt have to re-spin up...

I would assume as DV's are standard fitting that best performance is achieved with the turbo kept spinning as oppose to a pressure build up.

The old quattro was driven hard with a capital H, i cant imagine gear shifting to take very long so reduced need for the DV perhaps?

[Doug_RS2]

Or they kept their foot to the floor on gear changes? To keep the air flowing.