Do I need a restrictor pill in the oil feed line (-4AN) on my TO4 turbo? RX7 guys do this and some of the ones that don't blow smoke out the exhaust. When I started up my engine the other day with the turbo installed it smoked alittle bit. Not a black cloud but enough to make me choke when looking at the turbo exhaust outlet to see if the turbo was spinning. It seems that people are using a .125" orfice

 

Why were you looking at the exhaust outlet to see if it was spinning? You should be able to hear it, or check the intake side and see if the impeller is spinning. What you were probably choking on was... exhaust fumes. Most turbos will smoke a little bit when you run them for the first time. Is your turbo mounted above the oil pan or below the pan?

 

Yes, a resitricter will help. A major reason for seal leakage could also be a poor oil drain line, which should always be as vertical as possible, and ending above the oil level in the pan.

by adding the restricter your lowering the psi the turbo gets. You dont need much psi to lube the turbo put a restrictor with a .050-.100" hole in it (tiny), so you don't have to worry about too little oil.

 

Iasked this question a long time ago and the conscensus was that a 1/4 inch line (i think that is -4AN) was adequate for the turbo supply with no restrictors needed. I haven't run restrictors on the two turbo's I've cycled thru on my camaro, and I didn't have any problems with starvation in the turbo itself. the times I did have slight oil problems I would attribute to the poor (nearly horizontal) oil drain. My twin kit will not suffer the same problem, as they will be quite high in the engine bay.

Bill

 

Is that with a HV/HP oil pump or the stock spec pump???

I've been told the PT76GTS has an oil restrictor built into it, but the P and Q trims don't.

 

That is with a stock spec pump, I ran the PT-76 Qtrim turbo.

Bill

 

I see your cogs turning steve, or should I say impellers?