eniac

On non-BB hybrid turbos you can get away without a restrictor.

Porschefile

Sorry but, that's not 100% true. These cars don't really run any significantly different oil pressure than most other turbocharged cars. I've seen some that run as much as ~7 bar on OEM Garrett or Mitsubishi turbos (likely with built in oil restrictors at that level).

gt37vgt

yeh you can't survive with less oil pressure unless you have axial feed through the crank 1 bar per 1000rpm is common

special tool

Maybe a little lower, about 10 psi/1000.

eniac

Sorry but it is true that our cars have higher oil pressure then many other cars. Sure some are even higher which is why I said about 90%. I don't know many other cars that run 5+ bar when cold and 3+ bar when hot at an idle. Also I wasn't limiting this to just factory turbocharged car either as Garrets are universal and made with the assumption they would also be used on non-factory turbocharged cars.

~10 psi / 1k RPM is more common as ST stated.

Porschefile

300zx's, 240sx's, Supras, Eclipses, Grand Nationals, to name a few. While the 951 motors seem to run a bit more pressure at lower loads (meaning they reach 5 bar a bit earlier than most motors), there is nothing to substantiate a claim of them magically being higher than "90%" of turbocharged cars out there. There's just not much of a difference in oil pressure between these cars and most other turbocharged cars, and I can state that for a fact from personal experience.

Link Garrett's tech page has some interesting tidbits of info. They mention that a DBB GT series should have a restrictor for anything over 60psig. Just FYI to anyone interested. I'd highly recommend browsing their tech pages as there is some nice turbocharger info there, some of it GT series specific as well.

eniac

Again I stated that number as refering to most cars on the market, not just turbocharged cars, but all cars. Going by personal experience as well, almost all of the cars I have seen typically had 40-60psi pressure release valves so the psi could barely even get to what my car has at an idle.

~20 psi is common to see at idle for most standard cars.
My 1988 951: 3 Bar at idle.
3 bar = 43.5 psi.

Looks like twice as much to me.

~40-60 psi for most standard vehicles at higher RPM.
My 1988 951: 5 bar at high rpm.
5 bar = 72.5 psi

So not quite twice as much but it is still quite a bit higher.

If so many cars ran this high of oil pressure, Garret would build the turbos accordingly. They don't because some wannabe hotshot will want to throw a Garret in his, say, Cavalier(<20psi at idle, ~40psi on acceleration) which would completely starve a turbo designed for 951 range oil pressures.

anders44

don't make this a blablalbal thread

let's just leave it at the fact that BB turbos require a restrictor.

333pg333

"blablalbal" is this a Swedish delicacy?

nize

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.

from garrett's own page at;
http://www.turbobygarrett.com/turbob.../faqs.html#t16

tman

This thread is getting really old. I agree with anders44.

porshhhh951

+1 lets not ruin a perfectly good thread.

95ONE

Well, lets get back on topic then!

I Got the Adapter piece yesterday. It works perfect. I did have to grind down some support grates off the back side of the mount for the Turbine to fit properly. (Last picture) If I didn't have an extra long 4bolt turbine. I would have just bolted it on and started making the Down-pipe. It would push the Turbo a little toward the motor, but work great and still leave enough room for downpipe bolts.

BUT... mine extends leaving no room. Bottom bolt would never go in there due to the balance shaft housing. A delete kit here would be fantastic.

This is where more money for a V-Band, or a Tial Turbine housing would make this more of a bolt on Proposition. I highly suggest this option to anyone thinking about this upgrade.

95ONE

Agreed.

So I have to Turn the piece 180 deg. (Offsets the turbo to the right) This causes one problem. One of the mounting bolts - only one - has to be longer than stock. In the example mentioned above. This is not a problem. Just get one from 1.5 inches to one that's 1.75" Big deal. But...... Turning it around means I now have to extend the REALLY LONG bolt even further. This is not a in the store bolt. Good luck finding another one. SO.. I just took a long battery tie down bolt with a hook on one end that has the same thread size on the other. Cut it to length, and threaded the cut end to make it a stud. I removed the old bolt. (no small feat) and then bolted the newly threaded stud to the turbo. (Its reverse of the one in the picture.) Removed the Heat shielding For the brake M.C. and droped it in. I then made sure everything was clocked perfectly. (left all backing bolts loose and then clocked and then tightened one down on each side.) Then Ground down the top of the compressor housing. - needed it. There is now enouch room to put in all bolts on the 1/2" 4 bolt Downpipe Flange.

blown 944

very nice.

so the adaptor... would it work on a std garrett? I would assume so unless there is a difference in bolt spacing.

I ask b/c it would help get my turbine housing away from the balance shaft a little.

If it did work I guess I may get it, but I just got done with my up pipe and my down pipe .

I shoudl be able to fire it tomorrow but damn that little piece looks like it may add a little bit of needed clearance for the 4 bolt outlet flange I have on mine.