Thread: W10 Avenir turbo oil pressure

I am new to the world of turbo (previously had an all-motor high compression setup that was fun, but went boom), and I am preparing for the install of my W10 avenir into my NX. The learning curve is steep, but I am enjoying the process.

One question I have not had adequately answered during my research has to do with oil pressure for the turbo. I am replacing the stock T25 (journal bearing) with an S14 T28 (ball bearing). What I am wondering is if I need to modify anything in order to have the correct oil pressure fed to the CHRA on the T28, or am I good using stock pressure with the stock lines?

Thanks in advance for any advice!

Darrin

Ball bearing turbo's technically need less oil pressure then journaled.

I just took my Ball Bearing T25 off and am installing a journaled T28, they have a restricter built into the turbo. I'm hoping it will be enough oil pressure for the T28, but from what people have been saying it should be fine.

Taking a quick peek at the CHRA on the T28, it looks like there is indeed a restrictor there as well (I don't believe it is simply part of the fitting). I don't have the T25 to compare it to (came from Tiger with a seized turbo, which they are replacing), but I'll check it out upon the replacement's arrival. Spec'ing it into the CHRA from Garrett makes more sense than having a different restrictor in the block for each different turbo application.

Darrin

I didn't add/remove a restrictor when I put a GT-28 on my W10. She's been running for almost a year now and absolutely no problems with her. I had to have special lines made to fit the turbo. Basically I took the stock turbo lines and cut them up. I kept where the banjo bolt fittings were and mated them to braided stainless lines.

I had the same problem, the stock turbo was seized so it sounded like a good reason to upgrade to something better.

ball bearing turbos require a restrictor the built in is not enough. you need a .035 in line on the oil feed line. I have run one on every gt series ball bearing turbo I have ever owned and have yet to kill a turbo.

Ok, looking at the pics of restrictors I have found, it looks like I'd be dumping the stock feed line as well, and either adapting as Speculative did, or going end to end with a complete new line. Sounds like having the restrictor won't hurt a BB CHRA, and will only ensure proper feed pressure (even if there is a factory one inline somewhere).

Going on the shopping list! Thanks guys.

Darrin

Now does this mean that I will need to find and remove a restrictor going from a BB T25 to Journaled T28? I'm using the lines from a T28, I wonder if the BB T25 has all the restrictors built into the turbo/lines.

the stock oil feed line has a restrictor built in. the only thing you have to worry about with a bb turbo is it getting to much oi and starving it out. a journal bearing turbo also uses a restrictor but its larger than what is used on a bb turbo. All of this depends on the size of the turbo and oil feed line. iirc if you use a -3an line with a gt series ball bearing turbo the stock restrictor is fine. if you use a -4an line you must have the restrictor in line. if you don't have the right restrictor on a journal bearing you will blow the seals out. same goes for a gt series. too much oil pressure will destory the chra.