S15 dual BB T28: oil line restricter or not? (and a water line q)

[adey]

(Mods: Apologies, I meant to post here, can delete the one in engine tech!)
Hey all!
Has been a long ass time. Hope y'all are well.

I picked up a new old stock 91F00 S15 zenki ("dual") ball bearing turbo off yahoo japan, and am in the process of piecing together all the parts for the build.

On turbo lines (water and, specifically, oil), I have read a few different things on whether or not I need an oil restrictor.
All the forums and retailers seem to say that a restrictor with somewhere between 0.6-0.8mm diameter is needed at the turbo side of the oil feed line (http://www.frsport.com/ATP-ATP-OIL-0..._p_282811.html), but on some of the Japanese part company sites (APP and HPI, both very reputable as far as I know) there is nary an oil restrictor in sight, and both of them even explicitly saying that the S13 oil/water lines are directly usable on an S13 with S14/S15 turbo!

So... what gives? Is there a definitive answer on this?
The thing is, I've already picked up a set of HPI S13 lines, which do not have a restrictor included...

For reference, the HPI site:
http://www.hpi.co.jp/?cate=turbo&p=s...esh_trubo_line
(turbo oil line is even shared between the S13 and S14/S15! Item "A")

APP:
https://translate.google.com/transla...tml&edit-text=
(in the fine print, APP tells you to choose the oil line for the corresponding chassis, regardless of turbo)


On a related note, I have noticed that the previous owner of my car took the water lines off his OEM S13 turbo... but with all the junk in the way, I can't tell if the outlet on the block and the return by the firewall are still useable... any suggestions on how to go about finding out, or any idea how people tend to plug these up? (so I can gauge the likelihood of running into a threaded water outlet or something else that would seriously delay/slow my install.. which I hope will take no more than a full weekend!)

[Dboyizmlg]

91FOO DBB turbo will need this restrictor.

http://www.frsport.com/DIF-10016-Tur...-_p_16397.html

[adey]

Thanks, Dboyizmlg.

Noticed that that link is for a .04" (1mm) restrictor, while the DIF lines come with a 0.032" (0.8mm) restrictor. Any idea why?

And then, would this bolt on to the block side? Or straight into the turbo oil feed?

Then lastly... why? As shown above, most of the JDM manufacturers NOT have a restrictor...

[jedi03]

I would do a restrictor...I blew a brand new garrett by not running one...an it goes on the inlet side of the turbo...I recommend upgrade to the s14 braided lines and water neck to eliminate the line behind the head an get better coolant flow to the turbo

[Dboyizmlg]

Originally Posted by adey

Thanks, Dboyizmlg.

Noticed that that link is for a .04" (1mm) restrictor, while the DIF lines come with a 0.032" (0.8mm) restrictor. Any idea why?

And then, would this bolt on to the block side? Or straight into the turbo oil feed?

Then lastly... why? As shown above, most of the JDM manufacturers NOT have a restrictor...

The 0.032 restrictor will be good to use also.
That is the one I have on my gt2871r (DBB).
So yes, you can also use that one, actually I recommend that one over the other one.

You install restrictor on turbo, also keep in mind that the restrictor will not sit flush when you install it. So DO NOT over tighten.