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Discussion Starter #1
Motor specs -
-rebuilt GE bottom end, utilizing GTE internals. ( No oil squirters )
-GTE head
-GTE oil pump.

So here's the issue that I've been contemplating for a few days. Seeing as I'm using a stock GTE oil pump on an engine with no oil squirters...my oil pressure will be higher than that of a stock GTE motor. (This setup has worked fine with quite a few people) I will be running a PTE 6765 journal bearing turbocharger. I've read the precision turbochargers are picky about the amount of oil / oil pressure being fed to them... More so than a Garrett or Borg. Which makes total sense, they're not as high of quality. Not to knock Precision. I still like their product.. Sometimes

A stock 2J has approx. 90PSI at WOT (apparently). Assuming ill exceed that pressure at times, what's the ideal feed/return lines for the turbo? Precision recommends -4an feed / -10an return on their website, with absolutely no restrictors for journal bearing turbochargers. What do you guys think ? This will be my daily driver, not a track monster. Redline synthetic oil will be used.

Sorta leaning towards a -3an feed. More pressure, smaller hose... Precision has not responded to my email sent last week regarding this subject \

All input appreciated!
SS
 

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im using -3 feed no restrictor
 

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My 6466 DBB has been using a 4AN feed w/restrictor and 10AN return for over 2000 miles with no issues. My engine makes well over 100 PSI of oil pressure at WOT.

I've used the same setup with a journal bearing 6266 without issues.
 

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I spoke to PTE about this and they recommended a -3 feed on a BB turbo. Mine has 10,000 + miles with a -3 and is still in perfect condition running 40 psi for over 2 years.

Ryan
 

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Did you happen to ask about the JB turbos? I just made a -3 hardline for my 6766 JB. I'm hoping this was correct...
 

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I too am curious about this...

Also (and a bit off topic), where are you tapping into for the oil feed? Union bolt on the oil filter housing, drilling/tapping oil galleys, etc...? I ask because I'm doing basically the same build, however, I have decided to have my machine shop drill straight through the center galley to connect the left and right side oil banks together, and then drill and tap the factory capped two oil galleys that are normally open on GTE blocks. I have been told that the "quality" of oil from the union bolt method is not as good as the galley method due to the filtered/non-filtered oil feed.

Thanks.
 

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Discussion Starter #7
im using -3 feed no restrictor
whats the setup being used ?

I too am curious about this...

Also (and a bit off topic), where are you tapping into for the oil feed? Union bolt on the oil filter housing, drilling/tapping oil galleys, etc...? I ask because I'm doing basically the same build, however, I have decided to have my machine shop drill straight through the center galley to connect the left and right side oil banks together, and then drill and tap the factory capped two oil galleys that are normally open on GTE blocks. I have been told that the "quality" of oil from the union bolt method is not as good as the galley method due to the filtered/non-filtered oil feed.

Thanks.
I am running my feed from the oil pressure port, beside the A/C compressor.
 

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Discussion Starter #8
This is regarding PTE JB turbochargers haha. Sorry for the confussion everyone
 

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This is regarding PTE JB turbochargers haha. Sorry for the confussion everyone
Here is an email response from Dennis at Precision. I asked him what size should be used on JB turbos.

In most conditions a -3 works great. It depends on the oil pressure the engine holds at warm idle. 35psi or higher at warm idle then yes you can do that with a jb turbo. Any less pressure and the turbo will be damaged. Now with BB turbo the -3 works great to cut back on volume of oil to the turbo ( the turbo also has a internal .030 restrictor ). I hope this info will help.

Have a great day
Regards
Dennis
 

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Discussion Starter #10
Here is an email response from Dennis at Precision. I asked him what size should be used on JB turbos.

In most conditions a -3 works great. It depends on the oil pressure the engine holds at warm idle. 35psi or higher at warm idle then yes you can do that with a jb turbo. Any less pressure and the turbo will be damaged. Now with BB turbo the -3 works great to cut back on volume of oil to the turbo ( the turbo also has a internal .030 restrictor ). I hope this info will help.

Have a great day
Regards
Dennis
looks like i'll run a -3. thanks ryan.

Hopefully this will become an often-replied-to thread. Good info people need to understand.
 

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Here is an email response from Dennis at Precision. I asked him what size should be used on JB turbos.

In most conditions a -3 works great. It depends on the oil pressure the engine holds at warm idle. 35psi or higher at warm idle then yes you can do that with a jb turbo. Any less pressure and the turbo will be damaged. Now with BB turbo the -3 works great to cut back on volume of oil to the turbo ( the turbo also has a internal .030 restrictor ). I hope this info will help.

Have a great day
Regards
Dennis

I received similar info from them a while back regarding a 6766 journal bearing turbo. Also, ensure the feed drops straight down, and the return is at least a -10AN.
 

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I am running my feed from the oil pressure port, beside the A/C compressor.
From the driver's side of the motor? That sounds like a very long path, with many obstacles.

There are two threaded ports on the passenger side of the block (assuming originally one for each stock turbo). Use the one in the front and cap the one closest to the rear. Much shorter path.

On the line size: FSR includes a -4 feed line in their kits. I think the restrictor that Precision puts on the BB turbos makes the line diameter a moot point. How can more oil get to the turbo with the -4 over the -3 if the restrictor regulates the flow anyway?

Al
 

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Discussion Starter #13 (Edited)
From the driver's side of the motor? That sounds like a very long path, with many obstacles.

There are two threaded ports on the passenger side of the block (assuming originally one for each stock turbo). Use the one in the front and cap the one closest to the rear. Much shorter path.

On the line size: FSR includes a -4 feed line in their kits. I think the restrictor that Precision puts on the BB turbos makes the line diameter a moot point. How can more oil get to the turbo with the -4 over the -3 if the restrictor regulates the flow anyway?

Al
GE block. Its a 3' feed line that swoops right over the motor. Easier for me due to no AC compressor and the use of a greddy intake manifold. However, you're right. I wish i machined the turbo oil feed port while the motor was apart. But this will do fine. BB turbos don't need a lot of oil. The feed line size doesn't matter with them quite as much. Just have the right flow restrictor.
 

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Im in the process of installing a PTE 6766 DBB turbo with ETS kit. The kit came with a -4AN feel line. Am I reading everyone's response right in that the DBB turbo has an oil restrictor built into it which would effectively make it a -3AN so to speak?
 

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Guys,

When the manufacturer of your turbo recommends that a -3 feed is the one to use, just use a -3.

A -4 will work but will have a higher volume of oil according to PTE.
 

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what are the symptoms of too much oil pressure? I have never own a PTE turbo before. My last turbo is Garrett GTX4202 using -4 line and -10 return no problem at all.
Just went with PTE 6870 and I would see a puff of smoke after a pull. Is this oil pressure issue? My pump is highly modified.. and more then 160psi at WOT.

thanks
 

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what are the symptoms of too much oil pressure? I have never own a PTE turbo before. My last turbo is Garrett GTX4202 using -4 line and -10 return no problem at all.
Just went with PTE 6870 and I would see a puff of smoke after a pull. Is this oil pressure issue? My pump is highly modified.. and more then 160psi at WOT.

thanks
You would see oil leaking the seals and going in the turbine housing usually.. a puff of smoke is a symptom of that. And damn, 160psi!! That's a lot... is that when the oil is warm too?
 

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You would see oil leaking the seals and going in the turbine housing usually.. a puff of smoke is a symptom of that. And damn, 160psi!! That's a lot... is that when the oil is warm too?
yup when oil is warm and oil squirters intact. at idle I get 40psi
It's an accelerated performance oil pump with micro polished gear + shim.

there is 45 degree -10 fitting right after exiting turbo.. I will get rid of that first. You think that could be the problem? next will be -3 line.
will report back once and if I get this solved...
 
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