Switching my master power 76 out for a Precision billet wheel PT76/75 this weekend. My LQ4 has a 4an feed and a 5/8 return to the top of the oil pan now. I have heard the precision turbos don't like to much oil. Any experience with LS engines and precision turbo advice?

 

Try and do a 3/4" drain.. bigger drain the better.

Thats all i know

 

most people i've seen just run a -10 or 5/8's,even with this turbo but the bigger line can't hurt like nonnieselman said above.

 

I guess it depends on the routing of the 5/8" stuff.. straight down is better, put a few bends in it and it could back up.

 

It sounds like he's concerned with the oil feed, not drain. I would go straight to Precision, tell them your feed line size and oil pressure, and hopefully they will recommend a restrictor or not.

 

Most of the guys that answer the the phone at precision are unfriendly dumb A holes. There's a few good tech guys that actually know what there talking about when it comes to these ls motors. He told me that with the high ls oil pressure at wot which is around 80 psi I should run a -3 an feed and a big drain that's straight down.-4 may be a bit much

 

You never want to use a restrictor on a turbo if its not a ball bearing unit. -3 or -4 is fine. You want the drain at least -8, preferably -10 or -12, and straight down. I use a 6" pipe straight down off my turbo, then to a -10 line to the pan.

 

Not true. I have a -4 line and when i would go WOT it would push oil past the oil seals of my turbo. I had to use a restrictor.

 

Lots of people use restrictors. It varies from turbo to turbo whether or not it will push oil past the seals. With 80+ psi near redline I'm planning on using a restrictor. I will try it without one first however.

My -3AN fittings have a 1/8" ID so maybe that will be restrictive enough.

 

Im not saying a lot of poeple dont use them, but if your drain side is set up correctly, you shouldnt need one. The last thing you want to do is restrict oil flow to the turbo, and a restrictor lowers the pressure by limiting flow.