Rebuilding a VNT

[WickedShelby88]

Has anyone here done this before? Also what are the advantages to the carbon seal kit versus the dynamic one? I've got my mom's shadow apart and although there isn't much shaft play and it seemed to spool up fine I think since I am replacing the head gasket now would be the time to rebuild the turbo. One thing I did notice too is that there is a pin to keep the lever for the vanes from moving too far in the wrong direction. I imagine this is to keep them from contacting the blades of the turbine wheel. Also where would be a good source to get a waste gate can if this one is leaking?

[WickedShelby88]

Well after researching a little bit on parts availability and what tools would be needed along with getting it rebalanced upon reassembly I decided to talk myself out of this one. You can still get parts to some degree, but my advice is buy a few cores and keep them for parts. If something ever happens they will pay for themselves.

[Will Martin]

I've taken several apart and put them back together. Let's just say that you saved yourself a headache. The parts inside are so brittle from the heat/carbon build-up that you'd probably snap a few things inside. I think I've only taken about 4 apart that everything went well. lol

[BadAssPerformance]

If it aint broke, dont fix it. :thumb:

[CNH320]

Not to hi-jack your thread but due to the lack of parts for these i'm wondering if any of the newer "VGT" turbos that are being used on some of the newer diesel engines (powerstroke) could be easily adapted as a replacement/upgrade? Anyone have any experience with this? For a street car, the VNT is awesome, i wont go back to a non-VNT but sure would like a bit bigger version of it.


If it aint broke, dont fix it. :thumb:
Amen!

[zin]

Well, looks like I'll be embarking on this adventure, the VNT on the Omni seems to need a new oil seal, it sat for many years and was unknown when I got it as part of an engine/trans purchase.

I'd be interested in knowing what parts "snapped" and why, maybe I can avoid the pitfall? If there are any tips you can give I'd gladly take them under consideration.

BTW, I do have one fully blowed-up VNT (broken shaft) that I'll use first, but better to not have to "learn" the hard way if you don't have to!:nod:

Mike

[WickedShelby88]

Yeah I called Chris at TU and he gave me a good idea of why this was not a good mission to embark on as without more experience and some spare parts lying around I'd be kidding myself to say I was prepared. Virtually no shaft play and its not sticking so I think I will leave well enough alone. There are a couple "cores" for sale here. I may see about getting one for a spare for my mom. She loves the turbo car, but you can't have enough spare parts it you want to keep it VNT which I do. Those who have had these apart.. Do you think the small parts are something that wouldn't be too expensive to get machined out of stainless which I think is what was used initially.

[Aries_Turbo]

Not to hi-jack your thread but due to the lack of parts for these i'm wondering if any of the newer "VGT" turbos that are being used on some of the newer diesel engines (powerstroke) could be easily adapted as a replacement/upgrade? Anyone have any experience with this? For a street car, the VNT is awesome, i wont go back to a non-VNT but sure would like a bit bigger version of it.

i know some dudes are using the he351VGT that comes on cummins trucks. they rip off the controller and adapt a wastegate can to it to actuate the vanes. with the holset turbo, unless someone changes the position of the vanes (if its possible) when fully open, you have to run a wastegate as well otherwise it will creep pretty bad.

brian

[CNH320]

Yeah i found a few threads on this HE351VGT on some DSM forums as well. It'd be nice to be able to adapt the existing T4 VNT actuator then add an external wastegate to handle the creep. Or better yet if someone could do some code to use the existing PWM linear actuator thats on there already that'd be sweet...

[WickedShelby88]

I think there are some boost controllers out there that control vacuum with pulse width modulation, but don't quote me on that. I wish the VNT were bigger, but I would still put one on another car. Hmm maybe mated to a 3.0.

[BadAssPerformance]

Yeah I called Chris at TU and he gave me a good idea of why this was not a good mission to embark on as without more experience and some spare parts lying around I'd be kidding myself to say I was prepared. Virtually no shaft play and its not sticking so I think I will leave well enough alone. There are a couple "cores" for sale here. I may see about getting one for a spare for my mom. She loves the turbo car, but you can't have enough spare parts it you want to keep it VNT which I do. Those who have had these apart.. Do you think the small parts are something that wouldn't be too expensive to get machined out of stainless which I think is what was used initially.

Good advice, dont take it apart and possibly ruin a good turbo :thumb:

Bigger VNT? I'm guessing your mom just wants her car back?

[ShadowFromHell]

Does TU rebuild these? I have the stock one from my CSX that siezed on the way home from buying it. I pulled it and replaced it with a T2 becuase I had one, but have been thinking about going back to 100% stock. I still have the old VNT and all the goofy vnt parts.

[WickedShelby88]

Yes TU will rebuild these! Bigger VNT for mom's car.. Heck no. Going to put it back on since its still in good mechanical condition. I plan on getting a core to rebuild. Bigger VNT for my next car on down the road.