2G Modifying stock T25 oil return pipe with braided hose?

[Kryndon]

After rebuilding the T25 I couldn't manage to get the same rotation on the CHRA so now the flanges on the stock return pipe do not line up flush against the cartridge nor the oil pan. I tried bolting it down anyway and I bent the pipe and it's now leaking at the top flange.

My idea was to cut the 90 degree bend bit out of it and put either a silicone hose in its place or a steel braided hose (I think it should be AN12 or 17mm inner diameter). The part I will replace is circled red in this picture:

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Because the oil return is not pressurised and just flows down due to gravity, will putting either a braided hose or silicone on and clamping it down be sufficient? It would add a degree of flexibility and make it not so susceptible to the engine's vibrations.

EDIT: This is the type of hose I'm looking at getting:

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Thoughts?

 

[jjw205]

Yes. I did the same thing with my HX35 but I only used the end that bolts to the oil pan side since the HX35 has a different pattern on the center section. That is the best ID setup I could find. The 12AN fittings are smaller than the factory drain. So I figured that was the best option. If I can find a picture I will upload it. But it's pretty much exactly what you are thinking.

 

[Kryndon]

Yes. I did the same thing with my HX35 but I only used the end that bolts to the oil pan side since the HX35 has a different pattern on the center section. That is the best ID setup I could find. The 12AN fittings are smaller than the factory drain. So I figured that was the best option. If I can find a picture I will upload it. But it's pretty much exactly what you are thinking.

Awesome, I'd love to see a pic of your setup. For the T25 the ID is 17mm anyway and it's engineered to be enough so I'm not going bigger. Just need that flexibility so I can mount both flanged ends flush.

 

[Patchez_]

you NEED to have your turbo clocked properly the drain has to be angled properly or it may cause a restriction. there is bolts holding the center section of the turbo to the exhaust housing and a c-clip on the intake housing to the center section. loosen all of that and turn center section till stock drain lines up or the flange for after market is facing down with no angle like you have. afterwards tighten exhaust housing bolts and clock intake housing till waste gate is closed all the way. one question, i read you rebuilt your turbo did you have it balanced afterwords? also found from experience its good to change oil pump at same time if turbo was rebuilt due to failure.

 

[Kryndon]

you NEED to have your turbo clocked properly...

Basically there is less than 5 degrees of difference in how it's currently clocked. In fact I currently have the drain hole more perpendicular to the ground than before (slightly towards the block). It should not mess with the flow at all. However it appears the stock drain pipe is not quite angled at 90 degrees either, hence why I couldn't get the faces lined up flush.

I don't think I can reach the 4 bolts on the hot side to loosen them anyway without taking it all off. As for the turbo, there were two reasons why I decided to rebuild it. It had some shaft play (both axial and radial), and on boost I could hear a high-pitched grinding sound. I thought it may have been either compressor or turbine wheel. Upon disassembly, I did not notice any scratch marks inside the housings or chipping on the blades, and after rebuilding it and going for a test drive, I heard the exact same grinding noise. So the turbo may not have been that bad at all. But that's for another topic. Definitely no chance of replacing the oil pump at this time either.

 

[Patchez_]

for sure the hose setup you have planned will work fine but the metal from your previous turbo went somewhere which is why i ask about the oil pump. oil flows thru the pump before it hits the oil filter, low oil pressure is a leading cause to premature thrust \ bearing failure.

 

[1990TSIAWDTALON]

Hack off the middle of the drain and grab hose of your choice and clamp it on the drain at the pan and turbo. The others are correct that the drain needs to be as close to flat for drainage but if you give it a big drain it should work fine. If it "pools" at the chra, it will slow the turbo down and you will start smoking from oil finding an easier path out of the chra. For what its worth, I had a super nice -12an drain but it was such a stiff piece that was really only 4-6" long so I slapped a pc of 3/4" heater hose on as a test. If it wants to kink, put a hose clamp on the kink. It was a test for me, but it'a still on my car. I check it for getting soft everytime I have the hood open but so far it is fine. If for nothing else it can be a test size for you and your hose selection. Just some things I have done on my HX 40.

 

[Kryndon]

Well, I did what I could and with what I had. This is of course temporary and will be doing it properly later on. I will double check tomorrow for leaks but I think it's holding well. Also made my own gaskets out of 1.5mm thick black gasket material.

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[zedicus]

out of my own pure curiosity, why did you not just bend the flex section until it fit properly? that is what it is there for.

 

[Kryndon]

out of my own pure curiosity, why did you not just bend the flex section until it fit properly? that is what it is there for.

That was the first thing I thought and tried to do, but it can only bend so far and in fact the return pipe is not a straight down 90 degree bend but it's angled off to the side as well. So no matter how much I tried to bend it, the top flange never sat flush against the outlet on the CHRA. I could have marked its position precisely before I disassembled it but I forgot to. Fortunately it's sealing well now.

 

[Marc91utdsm]

I have found it very helpful to bolt the drain on the turbo before installation. Then you just have to worry about it lining up with the pan.