SOLVED Fun Boost Leak Lets See Who's Clever

Subwoofer

Sergeant
Jan 9, 2020
265
48
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335i
EDIT : CHRA was loose. I noticed some brand new oil on the rear coolant drain line, so I investigated the VBAND clamp. Ended up being loose.

Hello again all, been speaking to lots of people about this and to no avail, yet.

Current situation, new 19T get to boost target and then fall off around 5000 RPM (as seen in log below)

I would like to add, I have VTT aluminium outlets with the stock intercooler connection (not stock intercooler)

Things I have done :

Tightened and new seals inside of outlet (Including gasket sealer to help)

New Rear inlet as we were under the impression it had collapsed.

All new vacuum lines.

New PIERBURG Boost solenoid x 2.

2 x Diverter valve o rings.

Taken Chargepipe off and cleaned o ring ( no nicks) put back on.



Has anyone had a similar issue to this before ?
 
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SLOWESTN54

Lieutenant
Feb 9, 2021
698
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22
B.C. Canada
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2007 E92 335i / 2008 E60 535i
It could be your cars going way over target as you have much bigger turbos now, judging by how you kept boost below 21psi before im assuming your stock tmap. If you have a manual boost gauge it would confirm that.
 

Subwoofer

Sergeant
Jan 9, 2020
265
48
0
Ride
335i
What tmap sensor are you running? As somebody previously noted, there is a big throttle closure matching the duration of your boost plateau. This closure is because load actual hit load target. My suspicion is that boost plateau is actually a huge boost spike, only it's showing as flat in you log because your actual boost is much higher than your tmap can read. Your load also plateaus in the same region, but I think that's due the the throttle closure preventing load from over-shooting load target due to the huge boost spike that is erroneously showing up as a boost plateau in your log. If this is true, then where your boost drops back down after the plateau, is probably just boost coming back down from the spike back into a readable range for your tmap sensor.
Hey man!
Thanks for the informative reply, I’m actually running the n20 TMAP which I believe is up to 3.5 BAR. Which is around 29 PSI no ?
I’ll send this over to my tuner

I would also like to add that when it hits the “5000” boost falling off mark the car does feel less powerful. Almost like when it pulls before it’s going strong and when it hits 5000 it kind of “slumps forwards” just reduced engine power really

It could be your cars going way over target as you have much bigger turbos now, judging by how you kept boost below 21psi before im assuming your stock tmap. If you have a manual boost gauge it would confirm that.
Hey man. Before I was hitting 24PSI on 17t as I have the 3.5bar tmap sensor.
 
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wheela

Sergeant
Jun 4, 2021
360
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Twin Cities, MN
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2015 e84 X1 35i Msport
Hey man!
Thanks for the informative reply, I’m actually running the n20 TMAP which I believe is up to 3.5 BAR. Which is around 29 PSI no ?
I’ll send this over to my tuner

I would also like to add that when it hits the “5000” boost falling off mark the car does feel less powerful. Almost like when it pulls before it’s going strong and when it hits 5000 it kind of “slumps forwards” just reduced engine power really


Hey man. Before I was hitting 24PSI on 17t as I have the 3.5bar tmap sensor.

It makes sense you can feel it drop at 5000 rpm since the load actual drops hard at that point. I assume this is a different tune than you had with your 17t and 24psi? Maybe they forgot to scale the new tune for the n20 tmap? I don't know the in's and out's of scaling for the different tmap, but it really looks to me like boost is exceeding the tmap's range.
 

Subwoofer

Sergeant
Jan 9, 2020
265
48
0
Ride
335i
It makes sense you can feel it drop at 5000 rpm since the load actual drops hard at that point. I assume this is a different tune than you had with your 17t and 24psi? Maybe they forgot to scale the new tune for the n20 tmap? I don't know the in's and out's of scaling for the different tmap, but it really looks to me like boost is exceeding the tmap's range.
Hey. So since my 17T failed, I drove for around 1400 miles with one wastegate (never hard because I knew would damage further) I’ve always had a 3.5 bar tmap. The only thing that has changed is the 19T. I personally don’t think it’s a tmap issue. And more likely a boost leak, but the question is where!

I’m always open to suggestions though
 

zomski101

Private
Dec 28, 2019
31
7
0
Ride
335i
Find an shop to do a boost leak test, pointless to diagnose a boost leak over the internet unless you wanna throw money away. I'd say your inlets are still collapsing due to install error or shit inlets.
 

Subwoofer

Sergeant
Jan 9, 2020
265
48
0
Ride
335i
Find an shop to do a boost leak test, pointless to diagnose a boost leak over the internet unless you wanna throw money away. I'd say your inlets are still collapsing due to install error or shit inlets.
The pressure test items are on the way.

I did triple make sure it was all sitting circular on the inlets and they are clamped nicely.

Hopefully the pressure test when it comes finds the issue.
 

Subwoofer

Sergeant
Jan 9, 2020
265
48
0
Ride
335i
I would uninstall it (unclamp and move it to the side) and do one pull. That's me tho.
Might be worth a try, problem is without it on there could kill turbo, but a risk is a risk I guess. Hmmmm

just had a brain wave. My vacuum cleaner is a tiny bit bigger than the inlet. I’m going to connect it up and see what happens when I go full blast. I will be able to see the inlet collapse, I hope 🤣
 
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Subwoofer

Sergeant
Jan 9, 2020
265
48
0
Ride
335i
Yes the rubber boot on the chargepipe. Also are you using a stock airbox?

Too many stock parts and that is your restriction. I'm not sure if you're trolling or just daft.

What tmap sensor are you running? As somebody previously noted, there is a big throttle closure matching the duration of your boost plateau. This closure is because load actual hit load target. My suspicion is that boost plateau is actually a huge boost spike, only it's showing as flat in you log because your actual boost is much higher than your tmap can read. Your load also plateaus in the same region, but I think that's due the the throttle closure preventing load from over-shooting load target due to the huge boost spike that is erroneously showing up as a boost plateau in your log. If this is true, then where your boost drops back down after the plateau, is probably just boost coming back down from the spike back into a readable range for your tmap sensor.


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