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18mm thrust spacer and machining turbo housing

tektic

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In this video turbo lab tdo5 rebuild Austin talks about machining the housing with a flat tip carbide. He says that his 18mm spacer is an upgrade for the factory 14mm. He then goes on to show a turbo that has come premodified. I couldn't find any info anywhere else about this.

Has anyone here done this on their own turbo? How exact will this have to be? What level of precision is a carbide capable of?
 
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prove_it

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Looks like your just making extra clearance, so a little is all that is needed. I would try it. A steady hand and experience with a grinder is best though.
 

AllanL

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if you have the 18mm spacer already, slide it into the turbine's shaft.

of course, it wouldn't fit where the 14mm spacer originally sits, but you'll know how much to remove.

mark the step with a mini-driver and this is what you need to grind off...

2mm.
 
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prove_it

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This video actually re-motivated me to build up a bastard.
 

AllanL

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yes, tempting and easy... /ubbthreads/images/graemlins/grin.gif
 

BluFalcon

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That video was painful to watch.

The assembly steps were pretty straightforward, but some of the tools and techniques used during the assembly had me shaking my head. /ubbthreads/images/graemlins/banghead.gif

And not a damn thing mentioned about balancing the components, rotating assembly or the center cartridge.

As for using a carbide bit to clearance out the bearing housing deck to accommodate a larger thrust collar, you should be alright as long as you take it slow, don't remove any more material than you need to and make sure to thoroughly clean the bearing housing out afterwards. The only area you want to pay attention to while removing material is to ensure you don't remove material from the bearing housing that feeds oil to the thrust bearing.

It's not a critical machining operation, because all dimensional clearances for the rotating assembly are maintained by the pressure from the nut compressing down on the compressor wheel, thrust sleeve, thrust collar and the machined step in the turbine wheel. The rotating assembly is located in the housing by both the machined step in the bearing housing for the oil control ring on the turbine shaft, and by the thrust bearing which lays flat in the machined step of the housing. This ensures everything is properly located and should be unaffected by the removal of material from the bearing housing, so long as only the required amount of material was removed.
 
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GSTwithPSI

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So what's the deal with Turbo Lab? I've never heard of them until now. How about their billet 20g compressor wheels? Anyone here running one, and are they made in China with no R&D or are they legit? Seems like Turbo Lab has kind of a shitty rap over on T00ners, which is why I ask.
 

tektic

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I had them cut me a small 16g cover from a 14b. The first one they sent me didn't fit. I let them know and he said he used the wrong impeller to measure from. He sent me a second one that fit and looked pretty good too and the impeller that the first cover was cut for. All in all not a bad experience. I got what i needed and it was a good price.

Because they tried to do the right thing last time I ordered my rebuild kit from them. They sent me the wrong one. I brought it to their attention and they didn't seem too apologetic. I paid shipping back yesterday texted my tracking number to them and didn't receive a response. We will see what happens I guess.

As for the 20g wheel I had the same questions and did a little google-Fu. Consensus says the extended tips help but when connected to a tdo5 compressor it's not really worth the extra expense. You wont notice the difference between that and a cast 20g with the narrower shaft. If you step up to a sl or 06 compressor the bigger impeller can be properly utilized.

I briefly consider the narrow shaft 20g impeller but I have all this crap set up for a stock body turbo and if I crammed a 20g wheel in a 14b impeller cover I'm sure it would spike and surge like a sob. My s16g is overrunning my waste gate to 23psi as it is. If I were to get a bigger turbo I would need to go external. That means more new piping I would have to replace, and my car doesn't even have an engine in it at the moment... It's registered and insured though.
 
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prove_it

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I have my S16G set to run a spike of 25psi from 4k-6k then settle to 22psi til redline. I ported the living crap out of the wastegate hole and use an evo 3 o2 housing. I haven't had any issue with it.

Really thinking of a bastard now. I'd like to try a 38mm flapper and see if that will hold boost levels. Granted I'll push 25psi out of it so that might help keep it stable. Sounds like you and I are going to the same route.
 

tektic

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Yeah I have the modifyed 14b cover with ported e3 hot side, and e3 o2, 3" all the way back fed by a port matched 2g manifol, and cyclone intake.

The bigger waste gate door seems like a good upgrade. I'd like to experiment with that.

Though I have very little seat time with my current 16g, I enjoyed the time I had. After tuning I think it will satisfy me for a while. After all my goal with this car was autocross rally type vehicle. Spool count too.
 
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prove_it

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That's why I wanna stick with a tdo5h turbine wheel. Mine comes in hard, I'll be at 20psi when the cyclone opens up. Hell of a hit at 4200. Holds boost decent.

Picked up a 100 shot of nitrous to make up for the weaker top end for more fun on the drag strip.
 

tektic

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So I finally got around to rebuilding this turbo.


That's the housing after grinding away at it. I did a shit job. It's not easy. But the spacer clears and the turbos rebuilt. And everything spins smoothly.

Edit: Oh, and I took entirely too much off.
 
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prove_it

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Your going to feed off the OFH right?
 

AllanL

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just curious, but what would happen if it was feed through the stock oil supply port in the head?
 

prove_it

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The "upgraded" thrust washer has an extra oil port in it. This pushes more oil to the thrust washer, which is good, but if the oil supply is low then the bearings will starve. The head port can vary in oil pressure and is more likely insufficient for the rebuilt turbo. I got one turbo that this happened to sitting in front of me. Lasted all of 700 miles.

It's not an issue if a OEM thrust washer is used that doesn't have the extra port.
 

tektic

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The way I understand it, more oil volume will come from the filter housing. It is also oil that is filtered just prior to entry of the turbo rather than running through the entire engine first. I'd assume it's slightly cooler also because it comes from the pan and not strait out of the engine.

This makes me wonder how plumbing the turbo in this way will effect oil pressure in the engine. My particular turbo housing does not have as small of a restricter as most other journal bearing turbos I have seen. I also Just increased my drain size into the pan. Is it possible that low oil pressure can be realized because too much oil is flowing to the turbo and then right back to the pan. What is the proper size restricter for a an4 line with a journal bearing turbo?
 
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prove_it

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The turbo doesn't technically need pressure, it needs the volume. They go hand in hand and pressure can be physically measured so that's why it's generally used.

Your right though Tektic, the turbo needs more volume due to the thrust washer. There isn't that much oil pumping through the turbo, least not enough to cause the engine to see less. Our oil pumps can move a great volume of fluid(that's why people see 100+psi). Also it is cleaner and cooler (if a cooler is installed).

IMO, having fed off the housing helps restore oil to the cams since the head is notorious for having weak/varied pressures. Remember though, too much oil across the turbo will push oil past the seals and leak.
 

GSTwithPSI

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If you're using an aftermarket turbo, the manufacturer usually specifies operating pressure to the cartridge (which makes things easy). Since you're using a stock-ish turbo, you don't really have that luxury. Pretty much all MHI journal bearing turbos use a .075" restrictor from the factory, so that's what I'd stick with regardless of where it's fed from. I don't really know much about this mysterious thrust washer with extra oil holes, but I'd say it probably doesn't change how the cartridge should be fed oil.
 

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