Techno Duck

I was just wanting to learn a little about oil restrictors for non triple K turbos. What are the typical sizes you guys use for Turbonetics type turbos? I have a Turbonetics 60-1 HiFi that was used with a 1/16'' (.0625) restrictor. I read threads that confirm this size, but still left me wondering. I undestand the 951 engine has higher oil pressure necessitate this, but to go from practically 1/4'' down to 1/16'' seems pretty drastic? Im not really questioning it because it worked fine previously, but i guess im just amazed you would really need to reduce the feed orifice that much!

xsboost90

i dont have an answer but i do know that Sam Grant's car had this issue- the turbo would basically injest oil that was pushing past the seals due to the overpressure from the stock system.

SamGrant951

Yeah my new turbo was smoking a bit, installed a plug with a 1/16" restrictor and the situation improved drastically...was dreading the thought of pulling it for a rebuild so I tried the restrictor first - 1500 miles later and a few trackdays/dyno runs Im having no issues.

Techno Duck

Thanks for the input you two. I was just curious, it seems awfully small of a hole. I did some more reading on the subject and read a few things specifically on the Garrett webpage that most journal bearing turbos only need about 30psi of oil pressure to lubricate properly. Interesting stuff.

gt37vgt

I've always wondered about taking the oil from the head and perhaps it would be at lower pressure or a restriction would perhaps be more effective as it is further down the supply chain .