Harry Maneuvers

iTrader: (2)

So I have pretty hard boost oscillation through all gears on my ladies 04 wagon... I just built a SWEET boost leak detector and am ready to dig in... but being new to the turbo scene entirely... I figured someone here would extend the olive branch and show me how to do this properly.


I have read the directions for how to do it correctly through the turbo inlet... but I am wondering why do it there when you could just hook it up to the IC hose... I mean a pre-turbo boost leak is technically not even really a boost leak right?

Who here in the Sacramento (or even better Roseville) area has done this more than once and wouldnt mind sharing some wisdom?

Vladi

iTrader: (29)

that is boost oscillation due to tuning and/or solenoid

VRT MBasile

iTrader: (17)

Looking at the RPMs, that is exactly what my 02 with an auto tranny did. An off he shelf tune helped, but a custom tune obliterated the issue.

Harry Maneuvers

iTrader: (2)

Hmmm... well it already has a "custom" tune from DB/FW. The only thing that I have done since then was add the OEM boost gauge... I am pretty sure that my connections at the t fitting are solid though.

Whats funny is that on Saturday, after driving around for a little while... the car seemed to go into limp mode and not boost over .05, but when it was doing that... it was holding rock steady and the car would somewhat pull.

I talked to Paul about it a couple weeks ago and he said it sounded like a boost leak... Hmm... I will take in in on Wednesday and give him a day to figure it out... there have been no additional mods of any kind since the "custom" tune so I am not sure what to think.

VRT MBasile

iTrader: (17)

Then maybe it is a different issue

Harry Maneuvers

iTrader: (2)

So car is going into Paul on Thursday morning to see whats up...

I was really hoping to gain some knowledge from someone who has done this a few times...

I know I will enevitably need to or want to check for boost leaks and I just built a boost leak tester because I had nothing else to do haha.

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alien_refugee

iTrader: (2)

^nice rig, perhaps a bit overkill mang.

i would suggest you first go back to running the car without the boost gauge thingy. get a new hose of same id/length as stock, remove the one you spliced for the gauge and hook things back up. if it still oscillates, well use your nice rig tester and listen for pssstttttss.

otherwise you probably need to do a quick datalog of BCS duty cycle and turbo dynamics..
you could also set the solenoid map to 0 and just run off the wastegate. then do a log and if its still oscillating u probably have a boost leak.

oh and all the above ecu stuff requres some type of ecu tuning system (open source etc.)

good luck troubleshooting.

Harry Maneuvers

iTrader: (2)

I have AP v2 so I can datalog if needed.


I didnt think the boost leak tester was overkill... the rubber hoses are the perfect length to hang outside of the engine bay.

I think total cost of parts was like $31.


Ok I will disconnect my OEM lamco boost gauge and splice the line back together as if I didnt have a boost gauge hooked up.

DerekB707

iTrader: (21)

Make sure you regulate the pressure down. Don't pressurize the oil cavity either, had a buddy that did this and the dipstick shot out along with a bunch of oil. Just remove the lines off the inlet and plug them off. Just go a little over the pressure you run in boost a couple psi should do. Get some soapy water and squirt it everywhere you suspect a leak.

Harry Maneuvers

iTrader: (2)

So that is I guess my only question...

What is the best method for disconnecting and plugging or pinching the lines?




Using this image... going from left to right... there are 5 holes that I see coming off of of the turbo inlet... 4 black and the last one white.

Out of these... which ones need to be plugged and what is the easiest way to do this? Is it best to pull the line off and use a cap? Or is is better to pinch the line with a set of these:

DerekB707

iTrader: (21)

rubber caps from the part store with zip ties works very well.

I believe that the two that do not have hose attached to them are the ones. You want to pressure the boost side, which in the drawing you see the lines going to the boost controller and the tubro, the big one is for the recirc valve that goes to the intercooler which is boost. Open your oil filler cap when you do this, it will keep the crankcase from building pressure in case you miss a hose and you will hear it as well.

This is the one I built, fits perfect to a perrin inlet or I use a sleeve for the stock inlet.
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Harry Maneuvers

iTrader: (2)

What do you mean by "the two that do not have hose attached to them are the ones"

Going from left to right... the first two lines are vacuum line size... the third line is bigger, the fourth line is biggest and the fifth line is white.


Out of the 5... which ones need clamping?

DerekB707

iTrader: (21)

I'm doing all this off memory, my last wrx had a mbc and perrin inlet, the white thing gets eliminated in that process. My STi I have right now is bone stock. I'll be off work in 20 minutes and can post back when I get home, but I believe that you will only have to plug 2 & 3 (from left to right) when doing the leak down test. Hope that helps. Just hook up your device and build pressure slowly. Open the oil fill cap and listen for air in that cavity. If you are getting some coming out with those lines plugged, try taking a socket wrench and rotating the motor using the main pully, there is a spot where you should be able to get most of the air to stop. Just start with low pressure and work your way up.

DerekB707

iTrader: (21)

If you can, I would go ahead and plug off the one at the white connector as well. When I had my perrin inlet, that get t'd into the second hole making this job alot easier.

Harry Maneuvers

iTrader: (2)

Update...


So I dropped the car off with Paul at FW yesterday and picked it up a couple hours later...


Boost oscillation gone. Boosting up to 14.5 and holding strong.



And as a bonus... I have a boost leak tester for anyone who wants to test their car for leaks...

I only ask that I overlook as you do your testing so that I can gain the experience.