The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support ExtremePSI
Please Support Fuel Injector Clinic

16g oil restrictor ofh

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Janesfam

Proven Member
102
43
Jul 9, 2021
Milwaukie, Oregon
As I’m getting ready to finish up the 16g phase of my build, I’m reading a lot about needing a restrictor on the oil feed line to the turbo if I’m going from the filter housing. Nothing I have read gives a link or a size for any restrictor. My buddy is telling me to just remove the port and slap a 3/8bspt plug bolt and run a 1g feed line from the head.

this 16g phase should should only be on the car till after Xmas. And the fp green should be set up with the ofh port. So I guess what I’m asking is this.

what size restrictor should I use on the oil feed line running from the oil filter housing to the 16g turbo?

You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.


You must be logged in to view this image or video.
 
FP told me to feed the EVO3 16G with their AN-4 line from the OFH. It been running that way for more years than I can remember now.

IIRC it was the BB Turbos at the time than needed flow restriction to survive. Did I misunderstand or misremember?
MHI turbos require very little operating pressure to survive...they're sort-of a rare breed in that sense. Even the factory 1G feed line from the head contains a restrictor.

The concept behind a typical journal bearing turbocharger is to feed it as much oil flow as it can effectively drain within the manufacturer's recommended operating pressure while ball bearing is the complete opposite...ball bearing wants very low pressure and volume as it relies on coolant to control heat within the unit. For MHI TD05H turbos operating pressure is 42psi-48psi max; for other brands like Garrett the max is 65psi and Holset 72psi. If your pressure is above this momentarily it probably won't hurt anything, but if it's above this level consistently then you may need to restrict the feed to avoid filling the cartridge faster than it can drain and damaging the unit.


It's important to follow the manufacturer's requirements closely because every unit passes oil differently than the next. A MHI TD05H has a single 1mm oiling hole in the thrust plate from the factory while performance Garretts have three 2mm (or larger) oiling holes; obviously the latter passes more oil and needs a more-capable drain. Add to that the complication of how a 4G63 sits in the engine bay (leaning forward slightly) and suddenly the inlet at the oil pan isn't the lowest point of our drain system. So when someone takes a turbo like a Garrett or Holset then feeds it more than the recommended oil pressure from the filter housing then chokes the drain down to smaller than stock by using 10AN drain accessories which are often below 1/2" I.D. and the inlet at the pan isn't the lowest point of the drain, it's no wonder they dump oil like a fondue fountain. Poor PCV systems also make matters drastically worse as a viscous fluid will not drain by gravity into a space that is occupied with pressurized air. Anyone who has ever filled oil by funnel into a sealed container knows this quite well.

As the photo illustrates, the bottom of the oil pan is level:

You must be logged in to view this image or video.




Here are a couple good videos on the importance of a proper oil drain:

You must be logged in to view this image or video.

You must be logged in to view this image or video.
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top