im putting together a turbo setup for my 2001 ap1 and im using a Precision 60-1 journal bearing turbo. does anyone know what size oil line restrictor i should use?

 

This should be asked in the forced induction thread. The question has nothing to do with an S2000.

 

On a journal bearing turbo it really isn't as important as a ball bearing turbo. I have never used restrictors on journal bearing turbos, because they require more oil than BB units.

 

so as long as the return line is installed correctly and the turbo is clocked right the seals should be fine?

 

Yup.

 

Different turbo manufactures have different oil requirements. Check with the manufacture on there pressure recommendations and report back.

Journal bearing turbos do usually take a higher pressure. This can be a specific S2000 question because the S2000 has higher oil pressure then many other motors.

 

repeat lol

 

i called them and they said not to use a restrictor but that cant be right O.o

 

Um, just like I said. You don't need one with a journal bearing turbo. I've ran tons of journal and ball bearing turbos. Restrictors are only needed with BB turbos.

So yes, they are right, and so am I.

 

Straight from the Garrett site...

Does my turbo require an oil restrictor?

Oil requirements depend on the turbo's bearing system type. Garrett has two types of bearing systems; traditional journal bearing; and ball bearing.

The journal bearing system in a turbo functions very similarly to the rod or crank bearings in an engine. These bearings require enough oil pressure to keep the components separated by a hydrodynamic film. If the oil pressure is too low, the metal components will come in contact causing premature wear and ultimately failure. If the oil pressure is too high, leakage may occur from the turbocharger seals. With that as background, an oil restrictor is generally not needed for a journal-bearing turbocharger except for those applications with oil-pressure-induced seal leakage. Remember to address all other potential causes of leakage first (e.g., inadequate/improper oil drain out of the turbocharger, excessive crankcase pressure, turbocharger past its useful service life, etc.) and use a restrictor as a last resort. Garrett distributors can tell you the recommended range of acceptable oil pressures for your particular turbo. Restrictor size will always depend on how much oil pressure your engine is generating-there is no single restrictor size suited for all engines.

Ball-bearing turbochargers can benefit from the addition of an oil restrictor, as most engines deliver more pressure than a ball bearing turbo requires. The benefit is seen in improved boost response due to less windage of oil in the bearing. In addition, lower oil flow further reduces the risk of oil leakage compared to journal-bearing turbochargers. Oil pressure entering a ball-bearing turbocharger needs to be between 40 psi and 45 psi at the maximum engine operating speed. For many common passenger vehicle engines, this generally translates into a restrictor with a minimum of 0.040" diameter orifice upstream of the oil inlet on the turbocharger center section. Again, it is imperative that the restrictor be sized according to the oil pressure characteristics of the engine to which the turbo is attached. Always verify that the appropriate oil pressure is reaching the turbo.

The use of an oil restrictor can (but not always) help ensure that you have the proper oil flow/pressure entering the turbocharger, as well as extract the maximum performance.

You should not just assume your turbo does not need one, even if it's journal bearing. Honda's with vtec have higher oil pressure then most other motors. Like I said find out your turbos oil pressure range (get from manufacture, not dealer) and then I can tell you if any restrictor should be used. In some cases you do use them with journal bearing turbos, and every manufacture has different ratings for different CHRA's. My old journal bearing Turbonetics turbo I got with a revhard kit many many years ago came with one from the manufacture. It was coated on one side with red paint to tell if it was removed, eich would void your warranty.

 

That can't be right.

 

ill try to find out what pressure they recommend.

 

the correct size restrictor is .065 for non ball bearing standard turbos and .035 for ball bearing gt turbos

 

those sizes are universal(as far as turbos are concerned) for the ap1 oil pressure?

 

That is a good general guideline. I always run .035 restrictors in all my ball bearing turbos and have never had any problems. Journal bearing turbos are a little bit harder to get the right amount of oil to. Too little and they will burn up and too much and they will smoke like crazy. I would recommend calling garrett directly and telling them exactly what you want.

 

the guy at precision says the turbo runs optimally on 40-100lb of oil pressure.

 

if this was posted in the forced indution forum the question would have been answered a lot better... This is the S2000 forum...