RA OMP adapter install on a S5 T2 writeup

[Pete_89T2]

Originally Posted by JustJeff

Nice!! I thought about doing an adapter during my rebuild but decided I had enough on my hands getting the car off jack stands.

I love the mod but after seeing your thread I'm glad I didn't. I don't have the tools to mod the oil line from the front cover. But who knows, maybe after seeing your work I'll learn enough to do it...somewhere down the road...if I can ever get my car off the jack stands and back on the road.

Thanks - and don't let the turbo oil return line discourage you. After work today, I decided to get under the car again and do a test fit of the stock turbo oil return plumbing (without gaskets) just to verify that it wouldn't fit back on before ordering parts to fabricate a custom line.

As it turns out, I'm happy to report I was premature in thinking there would be interference. The stock return pipe barely clears the RA adapter, MOP and all lines with maybe 3/16"~1/4" space between the pipe flange at the closest point. You'll need to carefully route your premix line from the tank to the RA adapter to make sure engine vibration doesn't cause it to rub against anything, but this is easily do-able with some strategically placed zip ties.

You definitely need to remove the stock oil return pipe to give yourself enough room to install the RA adapter & MOP as an assembly. I also found it helpful to remove the stock M-fan. You can get by without removing it if you have smaller hands and/or better dexterity than I. Another caveat to add is to ignore the line in RA's instruction sheet that says not to remove the oil injector lines from the MOP. I started trying it that way, and soon found that the job was impossible with the lines attached.

When I have time to reinstall the oil return pipe properly this weekend, I'll take some pictures & finish the writeup.

[Pete_89T2]

Originally Posted by Pete_89T2

As it turns out, I'm happy to report I was premature in thinking there would be interference. The stock return pipe barely clears the RA adapter, MOP and all lines with maybe 3/16"~1/4" space between the pipe flange at the closest point. You'll need to carefully route your premix line from the tank to the RA adapter to make sure engine vibration doesn't cause it to rub against anything, but this is easily do-able with some strategically placed zip ties.

^I WAS WRONG!!! I should have tried to fully torque down the bolts on BOTH sides of the turbo oil return pipe when I test fit it earlier this week. Turns out it DOES interfere - you can bolt up the front cover side, but when you try to line up the bolts & torque down the flange on the turbo side, it's not going to happen. The bend on the stock pipe by the front cover flange interferes with the MOP. So now I need to order some flanges and some AN line & fittings to get this done.

[Pete_89T2]

Time to update this thread... Solved the interference problem with the turbo oil return line. First failed attempt used some cheap-o E-bay AL flanges with -10 fittings. These were machined in one piece. As it turns out, the turbo flange also fits the front cover, so I picked up two of them and the needed -10AN line & fittings to get from point A to B. Problem was the sub-standard AL used on those flanges was so soft that you couldn't tighten the fittings enough to make a reliable leak-free seal that would hold over time & miles driven. After less than 20 miles test driving, they started leaking, and tightening down a little more stripped the threads on the flange.

So then I got in touch with David Garfinkle of Garfinkle's Motor Works, and he fabricated a set of -10 AN/JIC custom fittings for me. These are a work of art and made of steel with proper fittings. No leakage problems now! I decided to retain the short stock return pipe on the S5 that bolts up to the front cover, add the Garfinkle's flange at the end of that, put the other Garfinkle's flange on the turbo and connect the two with -10AN line. There's a 90 degree fitting under the turbo, a short length of -10AN hose (< 1 ft), then a 60 degree fitting at the other flange. Picture below shows the result from the front cover side, where you can see how the 60 degree fitting routes around the extended OMP. I tried with 90 degree fittings at both ends, but that still interfered with the OMP.