Duramax turbo info

i think someone said it was hard to get info on new diesel turbos. well, i happen to have one sitting here on my bench, it has to go back for a core but i thought i would post some info if might help someone. it's not mine to use or sell, and i cannot disassemble it.

its a Garret VNT from an '07 Duramax LBZ, it has M48 cast into the tubine housing. turbine A/R is .90, compressor A/R is .58. it has dual inlets on the exhaust housing that face straight back. could to a usefull configuration if running EFI manifolds with J-pipes on a 300?

Garret P/N 8980385680
new one has P/N 8980117353
the difference in part numbers may only be that the new one is a reman part.

i could maybe get other measurments if you get back to me before the end of the work day today. i don't know a whole lot about turbos, i olny work with them in factory GM applications, so be spicific if you want measurements.

It might be helpful to have the exhaust inlet flange dimensions (hole locations and sizes) in case anyone wanted to build a setup for one.

Maybe rough external dimensions and inlet/outlet sizes and connections types (v-band, bolt on flange, or whatever)

the turbo mounts in the valley of the block via stand that is cast as part of the tubine housing and incorperates the exhaust inlets. the exhaust inlet diameters are 1.75" each. the inlet flanges are probably unique to these engines, they are a 3 bolt flange. the turbine outlet and the compressor inlet both use V-band attachment, 3.75" turbine outet, 4.375" compressor inlet. the compressor outlet is a standard hose and clamp type connection, 2.125" I.D., 2.375" O.D. the whole thing measures about 12" tall because of the stand araingment, 10" wide, and 11.25" long. vanes are controled by oil pressure and a 2-wire PWM solenoid, with a 3-wire position sensor.

i have some crappy cellphone pics i can try to upload later, or i may link to some better ones if i can find them later.

Well, it would be interesting to play with for sure. Unfortunately I don't have one laying around Maybe someone will try it though.

The .90 A/R is too large on the Turbine for a 300 six, unless ya turn it 5000 rpm or more. Might work ok on the Drag Strip ? I assume the Varible Vanes are on the turbine ? If they where workable, that would be a different deal? Thanks for the info., good to know

maybe I'm a weirdo.. but when I read his post about variable vanes that were controlled by oil, I pictured an additional oil line being run into the housing and then into the cab have a master cylinder with a lever setup on it (somewhat similar to a floor mounted e-brake) and you could adjust the vanes by pulling up or releasing the lever... Probably not what he meant though.. (I still think it would be cool)

-ron

yes, the variable vanes are on the turbine. there is only a single oil feed line that lubes the turbo and provides pressure to control the rack. i should also mention that this is a water-cooled turbo. i would think if you wanted full manual control you could machine a plug to replace the solenoid with a hole through the middle for a cable to attach to the rack. it would take some doing.

Here's a video of how it works: http://www.youtube.com/watch?v=Gc2awh0O0Bc

This should change the AR of the tubine dynamically, which is why the .90 AR wouldn't be as much an issue. Anyone know what output (electronically speaking) the vane position sensor has? Controlling the oil pressure solenoid shouldn't be difficult at all.

This info is based on my research/reading as I have only very little hands on experience with these turbos.

Manual control should be possible, though it seems to me that it would be easy to have very little boost, until a high RPM (as stated above), or choke your engine causing some high back pressure and exhaust heat. But, I've learned until you try it don't discount that it could work

it's a 3 wire sensor on a 5volt reference, you have 5v from ECM, a low ref (ground through ECM), and a signal voltage to ECM. sensor varies 0-5volts.