It was reaching it's limit alright. I overspun that turbo but the engine survived the turbo failure.
I am now on a modified GT2056V from a Jeep 2.8 CRD. This thing is a half size away from being a GT2260v:
-Jeep's stock 12 blade GT20 turbine has a GT22 sized exducer.
-59mm extended tip billet...
Upon closer inspection, my single piece bearings have a relief inside the same area.
Now I'm thinking its possible the shaft with the bigger cut might be paired with a straight cut bearing to cut down on machining costs of the bearing...
I can see how working with different bearings would change how you perceive the oil flow.
I could sure should state that I'm working with Garrett t20 VNT The bearings look like this.
I'm working with one piece bearings that run the full length. The thick one in the picture is stepped ever so slightly The ones I have on hand have no stepping at all. Some of the bearings have an oil groove on the inside running from one oil hole to the other oil. A step in the shaft certainly...
By "Bering seep" I mean more pressure inside the turbo causes the bearings to leak oil into the exhaust and intake.
On the straight shafts, they do make contact with the bearing in that area.
As far as drainage affecting pressure, it's harder to build up pressure when it's all flowing out the...
I've seen some shafts with a cutaway in the bearing area near the big oil holes. Most are subtle but some are quite noticeable. If anyone knows better please chime in.
Here's my best guess:
+more cooling from increased drainage
+less bearing seep from lower pressure
+Faster spool and top speed...
Update:
I went home for a month. Weather was a cooler than when I left but not quite "turbo season" and I did some tinkering.
I Ran out of preload adjustment trying to get 25 PSI and a hose clamp on the reference line would only yield 25psi max.
The next spring up was the same wire size just...
No dyno and not fast either. I'm conservative on fuel (low smoke) It just runs good and feels good. It no longer seems to care that I went from stock 27" tires to 32" tires.
Work has called me overseas for a year but I was at a good stopping point. :)
The supercharger is and Eaton M62( =1020cc/62cu) which came stock on 00-04 vg33er supercharged D22 and WD22.
It's ok in OEM form but finds itself a little lacking when you try to get a whole lot more out of it.
A TVS R1320 ( +1320cc/80cu) would make a sweet upgrade to it if I can find one but...
I'm not saying there isn't trade-offs, I'm just saying it works good :-)
There's a number of advantages vacuum control has especially when the vacuum line is ECU controlled in my case I think the two biggest advantage vacuum has over me is:
-Letting the engine breathe easier under light throttle...
yes indeed, I am running a VNT and controlling it with boost feedback only. I removed the vacuum actuator, installed a boost actuator and it works great! I set the stop screw for my desired early boost without too much surge and the actuator arm to control my desired peak boost. I bench tested...
Boy was I wrong! The GT22 makes plenty of boost if you drive it like a race car but nothing useful below 2500 RPM. The was frustrating mistake.
Take 2: I am now on a GT2052v with an oil only circuit and I am happy with it. There is so much boost volume that EGT's stay pretty low and heat soak...