Stock turbo Compressor upgrade

[ender]

Originally Posted by BaldTurboFreak If that were so Id be having real difficulties with boost creep and I'm not. It also would continue to happen and get worse in the upper RPM band. It's not. I have reduced it to a small area with cam timing changes. or you can run 18psi and never know about it. But Im an engineer, and engineers get extremely annoyed and inquisitive as to why the real word data is miles off the math. Im going to get to the bottom of this.

Could it just be that there's a sweet spot where the turbo surges because:

• At lower RPMs, the turbine section and exhaust flow enough to keep the motor using much of the air the turbo provides.
• At higher RPMs, the turbo isn't able to pump enough air to gag the motor.
• At just the right RPM range, the turbo flows more air than the motor can handle with the restrictive turbine/exhaust in place.

So maybe we need a larger turbine wheel too... or try clipping it just a touch.

[BaldTurboFreak]

I guess I dont have the whole picture without turbine inlet pressure.

But this is the compressor we're talking about here. What's bugging the hell out of me is htat it's happening at 18-22lbs/min. well in the nice island.
Maybe I'll take the compressor housing off and see about extrude honing it for increased A/r. THis will broaden the Map.
I also am looking into the possibility of
1) making a reflow housing
2)getting a wheel with a larger exducer
3)larger turbine wheel.

[ender]

I like 2 & 3 combined.

[LatinVenom]

Originally Posted by BaldTurboFreak BTW, LV I recieved your turbo this afternoon.

BTF:
This is GREAT but it looks like you have some issues to work out.
Once you are satisfied with the results of all the tests then let's proceed with the PLAN.
Of course if you want to use mine for some testing go for it.

On #3.
I thought you said the wheel you had was the largest it could be use in a safe manner?.

[BaldTurboFreak]

Holy moly bud, this thing looks like it spent time at the bottom of the ocean.

Also the meathead who cut the cat off with a torch got slag all over the turbine wheel.
The compressor housing is going to need a Ear welded back on it.
A new Bov cover.

It's true, I dont like the idea if a much larger exducer without an increase of shaft dia.

[BaldTurboFreak]

for those who want specs
turbine exducer:44.45mm
turbine inducer:49.91mm

compressor inducer:43.3mm
compressor exducer:59.2mm
Modstock wheel inducer: 46.8mm
modstock wheel exducer:59.2mm

THe exducer on the compressor wheel is actually 1.5mm smaller in backwall, the Borgie's have extended tips onthe wheel. so in one aspect you might say it's a 57.7mm.

[BaldTurboFreak]

The maximum possible turbine inducer that will fit in there is 2.0" or 50.8mm.

[BaldTurboFreak]

Look carefully at the dark black line on the map, it's becoming apparent that the combo of the soltice compressor housing and this wheel drops the "knee" in the black line to a lower pressure ratio.
It also perhaps flows out more, I have seen 38lbs/min so far. Steady.

[ender]

Originally Posted by BaldTurboFreak Holy moly bud, this thing looks like it spent time at the bottom of the ocean. Also the meathead who cut the cat off with a torch got slag all over the turbine wheel. The compressor housing is going to need a Ear welded back on it. A new Bov cover. It's true, I dont like the idea if a much larger exducer without an increase of shaft dia.

Damn, that sucks. Some people don't realize the care needed around precision components.

[LatinVenom]

Originally Posted by BaldTurboFreak Holy moly bud, this thing looks like it spent time at the bottom of the ocean. Also the meathead who cut the cat off with a torch got slag all over the turbine wheel. The compressor housing is going to need a Ear welded back on it. A new Bov cover. It's true, I dont like the idea if a much larger exducer without an increase of shaft dia.

BTF:
It came out of a 2007 GXP with ONLY 8000 miles on the DIC.
When they gave it to me it was already all wrapped in clear plastic.
I saw that they had cut the oil lines.
Just put a new BOV cover, could not tell it was broken.
Go ahead and replace ALL the Wheels with new ones.
I figure once is taken apart and Swaintech it will be better than a new stock one, and a lot more punch.

Below is a picture of our Turbocharger, you can see the wheel that will be replace.
Here is the link incase the picture does not show.
http://lh4.ggpht.com/saturnfan84/R3h...cotecturbo.jpg




http://lh6.ggpht.com/saturnfan84/R3h...2/P1010282.jpg

[mena661]

Not seeing the pic LV.

[BaldTurboFreak]

So comparitivly speaking the stock turbo is like a
GT20 on the turbine side and a GT2560 on the intake side.

With mod it's about the same as a "disco potatoe" GT2860RS but still with the ~50mm turbine.

[BaldTurboFreak]

A really great freeware program I discovered in college is Uconeer. In it they have a really nice gas volumetric to mass flow converter.
Using that in standard condition (60degF,14.7psi ambient pressure) the max flow possible comes at 244kpa and delivers 40.18lbs/min.

SO I stand corrected, and publicly apoligize to the feller that was asking if we could get 40lbs/min out of this wheel.
* under perfect conditions and with a free flowing exhuast/cat/intake & intercooler. It is possible that you can get 40lbs/min from this little peewee.

Unfortunatly the penalty for all that flow might be that you can only run ~19psi until you achieve 23lbs/min then you can run it up to the max kpa of the system. Easy to do with our factory computer &HPT. Or obvioulsy a pre-built tune.
265kpa is a nice number but impossible to do reliably until the GMPP opsystem is released.

Those of you that have "all the bells &whistles" already might achieve 23lbs/min faster than me (all stock. TRULY stock now other than the wheel)
Post up an HPL log of a car that has a big intercooler 3"race exhaust etc.. I'd like to see what the difference in flow is.

[LatinVenom]

Are you going to be able to take it to the track to see what it will do on the 1/4.
I know you do not have your Dyno inplace yet, so RWHP and Torque can not really be measure at this point.
A good 1/4 time and speed, would gives us a good idea, what we are going to be treated to in the future with this MOD.

[BaldTurboFreak]

Sure can. Mike isnt real busy this week. I'll try like heck to get an hour or two on his dyno soon.