Dive_Miguel

question for those that can relate.....

What is normally the minimum oil pressure required for the more common turbochargers we all use? I am not concerned with ball bearing or really small or big turbos but the more common sizes? I figure 20 psi would be sufficient....anybody care to elaborate?

RandysSOHC

you mean like a t3?

is that normal?

I thought a t61 was normal,
anyways,
I would say put it at 10psi & be done with it!

Dive_Miguel

Yea a t3 or something more "garden variety" in junk yards ect. I have read that the most common issue is TOO much pressure thereby blowing oil past the seals ect...

RandysSOHC

yea,very true,
but...
you'll notice your car smoking everytime your in boost before it blows the oil seals,
but when the oil seals do blow,you'll have oil in your charge pipes,

oil restrictor isn't a propblem to install or get,
my turbo I'm putting on this weekend is a td04h 13c from a 91 volvo 740
has a built in restrictor,,,,so it all matters of what turbo you get...

dcg9381

Need to measure oil pressure at the turbo before adding a restrictor, unless you've got a well documented make/model and other people are supporting turbos on that line & restrictor size.

With no data at all, the scientific method is to put oil gauges both before and after the restrictor, measure idle and at RPM pressure.. Pretty huge pain in the ***

Atticus

lol iv had mine almost hit 0 at idle before when im stuck in traffic and like 50-60 at higher rpm
i have a cheap as ---- air line valve on there
probably should up grade but meh... i just rev it a little

Dive_Miguel

thanks all....I remember that I used to see only about 10-15 psi at hot idle and around 40 psi at wot on the pos 88 sunbird gt (2.0 litre turbo ) i used to own.

MikeJ-2009

I know I should probably be an expert, but only quoting my general feel for it:

5psi minimum at warm idle
60psi maximum at warm WOT

I know most if not all have more than 60psi at warm WOT, but I would be more concerned with having under 5 at idle than a little over 60 at WOT. Wait, no I wouldn't. Junkyard turbos are cheap.

Inquisition

Garrett GT BB turbos like from 30-60psig warm under load according to Garrett. Journal bearings can tolerate and require higher pressure but if you were at 40-60psig I'm sure you will be fine. I'd personally shoot for 30psig.

fe3tcourier

this guy is onto it.

holset dont use a restrictor. whatever you can throw at it will be good for them.

i have a video of my engine cold cranking and the oil light staying OFF for 30s after cranking with a line to the turbo from the gallery! ie, it was only seeping through at the same rate as the rest of all the bearings in the engine were.

disconnect fuel and ign and try it... crank till you have oil pressure for sure and then some, then stop cranking and count till the idiot light comes on.

i say most likely no restrictor is best for most of them. i know some dsm guys have failures when they try to run em off the head oil taps. the head has a restricted feed to keep pressure high in the bottom end where its needed. oil in the top end is largely needed only by volume and not so much by pressure.

fred.