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RB25det turbo leak???

Ibanex

By Ibanex,
in Engines & Forced Induction

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Ibanex Rookie

Ibanex

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Hey guys,

I d like to ask for advice... My newly bought skyline running perfectly on 7 psi but if i raise the boost to 10 psi it cuts out at 6000 rpm and i just cannot tune it out.... when the engine is hot its getting worse (5500rpm)... I connected a  smoke machine to check for leaks...I marked the blocked pipes with red X....the smoke is immediately (at low pressure) coming out from the crankcase and from the inlet manifold...

20171216_140137.thumb.jpg.b0cb2b297a41de7fa8a06aa2f0b9dde8.jpg

 

It just doesn`t make sense to me how can it smokes from the engine when everything is blocked... Is my turbo leaking through the bearing housing back to exhaust and through the open valves comes out at the inlet? Or is it normal? Any idea? I m kind of getting hopeless for now maybe just i m the dumb and cannot tune it out (datalogit power fc, Z32 maf)... pls don`t spare me everything helps, have a good one

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Ibanex Rookie

Ibanex

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Sorry about that i just didnt make a picture how the smoke was connected so i tried to improvise.... I connected the smoke to the inlet before the turbo (blue arrows).... I blocked the inlet from the intercooler so it should hold the pressure... but it s not holding any pressure since the smoke is coming out from the inlet manifold and the crankcase where the red arrows are with the ???.... And that s what i m asking if it s normal?

20171216_140137.jpg

RB25Detonator Contributor

RB25Detonator

Posted
Posted

I assume you have the breather pipe and bov plumb back pipe blocked that comes out of your stock intake pipe. Try blocking it closer to the turbo, for example, block it before it enters the intercooler.

or, enter smoke right after the turbo and block off the same as your picture^^

Ibanex Rookie

Ibanex

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NEO25T: I think I m gonna try it on the weekend

Kinkstaah: yeah it is an Apexi Power FC with Datalogit I have a log file what is happening...

the AFR at the cut point is about 10.75 (so it s not too rich or too lean) I ve tried to adjust the airflow data....change the whole MAF...still the same... after the car is hot the cut is happening at 4320 mV or less... It is a Garrett GT28 turbo, 7psi wastegate with a turbosmart tee set to 10psi

boostcut.png.c36ca76b7d6fa524fa18e7c69d94fdd0.png

RB25detonator: yeah i ve done it too leaking out on the same places (crankcase and inlet)

NEO25T Collaborator

NEO25T

Posted
Posted

Out of curiosity how did you block the pipes?

The easiest way i found was to bag the end of the pipe with black plastic and clamp it back together. 

What spark plugs are in it, thinking back mine cut out like a rev limit at 6k when i got it. The plugs in it were nasty and new ones fixed it up

KiwiRS4T Grand Master

KiwiRS4T

Posted
Posted
On 4/18/2018 at 8:50 PM, Ibanex said:

yeah I used rubber gloves with clamp for alloy inlet and for the hose used degreaser can and clamped it  for smaller pipes just bolt and clamp.

I thought about the plugs too and I changed them last week for NGK BCPR7ES... they should be fine right?

They should be OK but Iridiums better. If you still have stock coils are your plugs gapped down to ).8mm?

Ibanex Rookie

Ibanex

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the only thing is that it really doesnt feel like a missfire...it just cuts out all together...  these plugs came already gapped to 0.8mm and the coilpacks (blue splitfires) should not be older than 2 years... so not too much left just keep on experimenting and spending some money...

  • 2 weeks later...
Kinkstaah Grand Master

Kinkstaah

Posted
Posted

If that is a full WOT pull, from the entirety of the video (i.e not backing off) and boost is dropping into massive vaccum like that, I'd be putting my money on that stock silicon hose sucking shut.


Especially given you said it runs fine on stock boost...

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