Supra Forums banner

1 - 20 of 24 Posts

·
Registered
Joined
·
67 Posts
Discussion Starter #1
Greetings SF Team,

After much fiddling, I was able to get my oil return fittings to fit by clocking the Precision turbo 15 degrees and using a 90 degree male to female -10an adapter fitting.

I will also heat wrap all my turbo exhaust manifold headers to protect the oil return fittings. Do you guys think this 75 degree is enough angle for the oil return path considering I’m already using an oil restrictor on the turbo feed line?
251664
 

Attachments

·
Registered
Joined
·
4,418 Posts
75 deg normally is not great as there should be no reason it's not 90 deg, but the 90 deg fitting right below the turbo is of much more concern. The oil line ideally should be able to drop straight down with the only bend being near where it connects to the block. Custom header I presume?

That radiator hose connection is of some concern also. Looks like you need the Twins Turbo thermostat housing rotator. That will drop the hose straight down.

Al
 

·
Registered
Joined
·
392 Posts
That's too sharp off bend right out of the cartridge. It will not run freely enough and back up into the cartridge at higher rpms.

A 45 degree would be much better off.

Sent from my SM-N960U using Tapatalk
 

·
Boost Junkie
Joined
·
12,527 Posts
Drop the 90 degree at the top. You should be able to clock the turbo more so that it drains straight out. Use a straight fitting at the turbo and if you need to, run a longer line into a 45 at the pan. Also, you need the PHR or Twins Turbo radiator housing adapter so you can clock your coolant line to move it out of the way.

Do not use the line and fitting you have on there now. It's too restrictive that close to the turbo.

Steve
 
  • Like
Reactions: SupraMan36

·
Registered
Joined
·
67 Posts
Discussion Starter #6 (Edited)
Thanks for the feedback guys. I was referring to 75 degrees off the vertical center line (90 degree [black fitting below turbo] - 15 degrees from clocking turbo).

The oil return path after the turbo oil outlet in that picture has about 2 inches of straight downward distance before that black fitting turns 90 degrees to the left. I cannot make the oil return go straight down because it hits the manifold.

Also, I have to clock the turbo this way to fit a wrench on the last turbine housing bolt. Oil feed restricter on the top is used because Precision Turbo told me to 😛.

This is a solution another forum member came up with (same style manifold as me) and I’m thinking of doing something similar. What do you guys think?:
251669
 

·
Registered
Joined
·
4,418 Posts
I think that manifold is sending you down a dark path, First using the bolts instead of studs, then the oil return line with bends in it. I would sell that manifold and get a proven one that you don't have to make provisions for. My 2 cents.

Al
 

·
Registered
Joined
·
67 Posts
Discussion Starter #8
T6Rocket, it’s also the only thing stopping my car from running. So, it’s too late to turn back now.
Can’t that -10 an aluminum tube in the above picture act as a small resevoir, thereby not restricting oil return flow?

251693
 

·
Boost Junkie
Joined
·
12,527 Posts
Here is what I would do. Call SP and get one of their stud kits for a manifold. Use the studs and nuts. If you need to get to a hard to get to fastener you can lift the turbo if needed in order to install it and then cut your wrench up if necessary so you can tighten it. For the drain, the problem is you have a 90 and then a 75 immediately after it and then another turn into the pan. Since the oil is not under pressure after it goes through the turbo, those turns are an issue. You really need to come straight out of the turbo and then take a smaller turn at the manifold if needed. If you can come straight off and then use the 75 degree fitting at the manifold, that would help a lot. What do the insides of your fittings look like. Most recommend a -10 for the drain. I have a feeling yours necks down to much less than that.

That manifold design is also very poor.

Steve
 

·
Registered
Joined
·
67 Posts
Discussion Starter #12 (Edited)
The input from you guys is great!

All oil return fittings and lines are -10an. (I cannot order parts because I’m in a time constraint.)

Since I have to clock the turbo so the return outlet is above the runners (15 degrees off vertical center line is max according to Precision Turbo), I think I can fit a 3/4 inch long straight tube off the turbo oil drain outlet flange and a 45-or-60 degree to the left (passenger side). I’m using ~ 1/2 inch aluminum tubing that is just over 5mm internal diameter bigger than -10an fittings. Do you guys think the 5+ mm bigger internal diameter will help enough with flow such that the 45 (or 60) degree angle won’t cause a restriction?

251709
 

·
Registered
Joined
·
67 Posts
Discussion Starter #13
I couldn’t wait for you guys to respond, so i modified my design with thicker shedule 40 pipe that is only +2mm bigger diameter than -10an (easier to weld thicker wall pipe).

After re-connecting the driver’s side pcv valve to the intake manifold, no more smoking turbo at idle. So, it works (so far)!

Now that there is more room under the manifold, I’m considering changing the current -10an SS braided return line to a -12an to give me less flow restriction. What do you guys think? 🙂
251767
 

·
Registered
Joined
·
4,418 Posts
As mentioned, you need the Twins Turbo thermostat rotator piece to rotate that lower water neck. Currently, you're looking at an unnecessary bend to connect the turbo to that pipe, when it could drop straight down. That lower hose currently has an uncomfortable connection there, which even just the stock setup should not have.

Getting back to the oil line - is there any way at all to run the oil line towards the motor instead of away from the motor, then having to double back? That is what is giving you most of those tight bends. It didn't look you could with that header, which has the pipes in all the wrong places.

Al
 

·
Boost Junkie
Joined
·
12,527 Posts
Too many bends man.

Steve
 

·
Registered
Joined
·
67 Posts
Discussion Starter #17 (Edited)
Hey guys,

The issue with turning the turbo oil drain towards the passenger side is it makes the bottom right turbine bolt impossible to reach with a wrench...even after i ground and cut one up. This is at Precision Turbo’s recommended 15 degree clocking limit off vertical center line.

This is the most downward angle I could create without hitting the merge collector, lower #1 header, or back of the compressor housing.

What’s weird is I’ve seem oem turbo cars with smaller diameter oil drain lines with 90 degree bends right after the turbo and they work fine...so why can’t my bigger diameter return at less than 90 degree angle work fine too? 🙂

251768

251769

251770


251772
my Turbo drain flange is on Right side ( bigger and deeper opening) and the Vibrant Performance one is on the left.
 

Attachments

·
Registered
Joined
·
67 Posts
Discussion Starter #18
You guys got me worried with your comments. I tried a new 45 degree 1/2 inch npt to -10AN fitting with a new -10an female Vibrant Performance Turbo drain flange that gives me more downward slope. But, this leaves no room for heat wrap at the manifold collector. Plus, I still cannot get to that turbine bolt...will try a shorter T4 nut/bolt on the turbo flange to give me 1mm more clearance.
Another perk of this new route is the oil return is angled away from headers.

What do you guys think of this new oil return setup:

251774

251775

251776
 

·
Boost Junkie
Joined
·
12,527 Posts
That looks much better. Just make sure the inner diameter of those fittings/adapters doesn't neck down.

Steve
 
1 - 20 of 24 Posts
Top