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Ok so I have a built rb26 running a nitto oil pump with all the usual mods. I have just fitted a new pair of -5 turbos and under the instruction of the distributor I did not fit an oil restrictor to the oil feed line. The oil feed line is -4 braided and I use a 90deg fitting into the turbo not a banjo bolt. After starting the car and running it for 10 mins there is a slight bit of smoke out the exhaust on idle which increases greatly as the rpm rises. I believe this to be too much oil pressure to the turbos. I have been tossing between fitting an inline oil pressure regulator which is made by peterson. I like this as I have control at a valve like setup. Or inline restrictors.

I know the inline oil restrictors is tried and tested, but is there a reason people don't use a valve like setup? If I run a restrictor does it need to be fitted at the turbo connection or can I fit it at the block?

Any help would be appreciated

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hurry and fit the oil restrictor, you can damage the turbo very quickly...

best to put it on the turbo, something like this.

http://www.atpturbo.com/mm5/merchant.mvc?Screen=PROD&Store_Code=TP&Product_Code=ATP-OIL-021&Category_Code=

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I spoke to garrett and countless tuners and shops etc most don't use restrictors and I think none use them in stock lines , problem is that 1mm is too small and there have been cases of damaging the bearings due to lack of oil so damned if u do or don't, every engine is different but 1.5mm I think is about right size but as std banjo is about 2.5mm hardly worth the effort as with such a large oil return it really shouldn't be a problem . Interestingly the ppl who rebuilt my turbos explained how the seals work to me and it seems many ppl have bad catch can setups that put pressure on seals and somehow cause them to move due to pressure differential and they leak. Anyway best of luck with this one, my best comment came from crd who said we don't sell restrictors but what we do is something we keep close to our chest which is fair enough I guess.

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  • 1 month later...

Hey any further info on this Shazz? Sorry to hijack but I'm interested to see how you got on as I'm having the same problems as you and a few others as well.

Basically built 26, usual mods new -5's originally with trust oil pump which turned out to be a copy causing high oil pressure. Found out after I had already fitted 1mm oil restrictors to the banjo bolts and then removed the front turbo (only one leaking) and sent back to be inspected all came back clear so engine out new N1 pump with billet gears oil pressure solved.

Had it in to get tuned last Thursday and apparently it's still smoking oil smoke out the exhaust when it comes on boost. Not doing it on idle like it was with the old oil pump just once the turbos are working. Pulling my f**king hair out because this has been going on for 9 months now and EVERYTHING is brand new. Only thing that's not new is the stock oil feeds. Haven't had a chance to pull anything apart again but the mechanic pulled the intakes off and there's no oil in the front housings so he thinks rear turbo oil seals.

I was wondering as an absolute long shot whether one of the hard lines is blocked causing all the oil to feed to the one turbo pushing it past the seal. Got no idea if this is even possible but ever since I bought the car and with 3 different sets of turbo's (2 were 2nd hand stock sets) I've had oil smoke out the exhaust and the only original thing on there other than the block and head which have both been reco'd is the oil and water feeds.

Gonna pull the y pipe off and see if it's one or both of the turbo's leaking and which one (was the front last time) and also pull the oil feeds off and test them.

Anyway just wanted to see if you had any luck with yours.

Also Guilt-toy mentioned you can damage your turbo quickly with high oil pressure could this be my problem? Car has done exactly 0kms other than what it did on the dyno the other day.

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