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So, my Wesitec tuned and upgrade GLA45 was having power issues. My boost is peaking about 25psi and then drops off to about 22psi while still WOT. Has anyone had any issues with the Wastegate? Weistec wants me to do a vacuum test on the wastegate to test it, but I am not sure how to go about that. They say you can't buy it separately from the Turbo from MB. Mamba makes one, has anyone tried them?
 

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So, my Wesitec tuned and upgrade GLA45 was having power issues. My boost is peaking about 25psi and then drops off to about 22psi while still WOT. Has anyone had any issues with the Wastegate? Weistec wants me to do a vacuum test on the wastegate to test it, but I am not sure how to go about that. They say you can't buy it separately from the Turbo from MB. Mamba makes one, has anyone tried them?
Hey,

another ideal use for datalogging.
Most oem turbo's are internally wastedgated
spring closed, vacum opened.
a leak would produce overboost
tapered boost profile is common with a smallish turbo, they tend to get out of the envelope before the mechanical rev limits
 

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Discussion Starter #3
This is how we see the drop in boost, which was through the HP Tuners data logging. It peaks at 25psi then slowly drops to 22psi while still in WOT. I am happy to share the HP file for anyone to review and add their thoughts. Weistec seems to indicate this was not normal and wanted an "opening" pressure measured and see if it stays open with the 25psi
 

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Ok,
So I don't know what the commanded target for that tune is, but, To target 25 at say, 4750~5250 rpm, with a taper to 22 at redline, sounds to me as a perfectly reasonable curve shape. whether the values should be 28 and 25 I dunno
What the weistec tuner, is telling the shop foreman to tell the CS to tell you, is that he wants a log pulled on straight spring pressure.

depending on how the BCS is plumbed, leaks in different places will show different problems. to diacnose, he wants just spring pressure.
But that, is outside the scope of the average user, so.. find a place to have a boost leak done. but with our hardware so buried.. Dude, I know exactly conceptually, how to do that, and on a speed3, take me an hour. on the 45, would take a day to get it apart enough to know I had all the ports plugged etc.



You seem hung up on WOT, that boost is falling even tho you are pressing on the pedal as hard as you can.

that would be relevant only if the log.contained commanded, and actual throttle openings,.... and they differed
 

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Discussion Starter #5
Ok,
So I don't know what the commanded target for that tune is, but, To target 25 at say, 4750~5250 rpm, with a taper to 22 at redline, sounds to me as a perfectly reasonable curve shape. whether the values should be 28 and 25 I dunno
What the weistec tuner, is telling the shop foreman to tell the CS to tell you, is that he wants a log pulled on straight spring pressure.

depending on how the BCS is plumbed, leaks in different places will show different problems. to diacnose, he wants just spring pressure.
But that, is outside the scope of the average user, so.. find a place to have a boost leak done. but with our hardware so buried.. Dude, I know exactly conceptually, how to do that, and on a speed3, take me an hour. on the 45, would take a day to get it apart enough to know I had all the ports plugged etc.



You seem hung up on WOT, that boost is falling even tho you are pressing on the pedal as hard as you can.

that would be relevant only if the log.contained commanded, and actual throttle openings,.... and they differed
OK, thanks. I bought a vacuum and crimp kit to replace the one that is holding the hose in place. Should be a pretty easy test and easy to check what the mechanical WG is opening at, and see if it can hold the 25 PSI too. The logs show commanded throttle at 100% the whole time WOT.
 

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So,.. you can data log, what is the WGDC ? sry, blanked a bit on that, at the moment, you need a lot less crimping and tinkering, and alot more data points.
how many channels can you log at once, and is it polling at least like 4 times a sec or better?
there is a long list of capital letter jargon items that when graphed will clearly show what is the root cause.of the fault.
Fault, still what I am not hearing, I mean whats wrong?

anyway, once youve logged wgdc,rpm,map, etc and that data shows uncontrolled actual map, with the ecu trying to command less, or more.
then, isolating the EBCS, would for sure be next, they do STB occ
if that was good, then you land in kookyville, testing for a partially torn WG actuator diaphram.

imho, some reasoned data gathering, should preclude a mad dash to rare part replacement land
 

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Discussion Starter #7
Here was just a screenshot of my logs where you can see the boost (light blue) go from 25 PSI then slowly to 22, while under the same WOT.

26511
 

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So, my Wesitec tuned and upgrade GLA45 was having power issues. My boost is peaking about 25psi and then drops off to about 22psi while still WOT. Has anyone had any issues with the Wastegate? Weistec wants me to do a vacuum test on the wastegate to test it, but I am not sure how to go about that. They say you can't buy it separately from the Turbo from MB. Mamba makes one, has anyone tried them?
weistech tuned and less than stock psi????
Stock should be at 26.1psi.
The video bellow shows how to set the wga.

 

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Discussion Starter #9
weistech tuned and less than stock psi????
Stock should be at 26.1psi.
The video bellow shows how to set the wga.


Great video, but I need to set a VACUUM (not pressure) to the WG. I can't find a vac that will give me a 25PSI vacuum to set/test. I bought one on Amazon but while it can go to 30PSI for Pressure, it won't go above 10psi for vacuum.
 

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Great video, but I need to set a VACUUM (not pressure) to the WG. I can't find a vac that will give me a 25PSI vacuum to set/test. I bought one on Amazon but while it can go to 30PSI for Pressure, it won't go above 10psi for vacuum.
i thought you ll need to test at what (in.gh) wga totally closed which is sould be between 12-14in.gh i used might vacuum pump to check it.
 

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also. pureturbo has some info. i would ask for Jimmy there. also you can email them your logs?
 

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i thought you ll need to test at what (in.gh) wga totally closed which is sould be between 12-14in.gh i used might vacuum pump to check it.

Correct me if I'm wrong, but I need 25 PSI to accurately test the WG, mity vac and others only do a maximum vacuum of 25" Hg (85kPa) @ sea level. 25"HG is 12.2 PSI, far short of the 25PSI I need to actuate and see if it holds at 25PSI.
 

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Correct me if I'm wrong, but I need 25 PSI to accurately test the WG, mity vac and others only do a maximum vacuum of 25" Hg (85kPa) @ sea level. 25"HG is 12.2 PSI, far short of the 25PSI I need to actuate and see if it holds at 25PSI.
sorry not sure, but call pureturbos in california they can help.
They build turbos / rebuild our turbos too. very familiar with low boost pressure.
 

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So


correct me if I missed a post,
If you had pulled into the magical no fault AMG tuner shop. Spoke with the concierge,
the ticket would start
"Customer states boost values taper toward redline, despite full application of throttle"


If thats the case, After a plugin and drive, you'd get your car back with a more ncely worded version of;

,... Yup, they do.
 

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No help here, but was good to see you today at LS. Name of the shop I had mentioned is Equilibrium Tuning in Suisun City. Based on their website, they haven't picked up the GLA yet, if they plan to at all. But they know high boost 4 cyl in general, and are good people. I met the sales mgr, service lead, and one tech, all good people. BUT, beyond that, I cannot vouch for them, since I have not had them do any specific work on my car. The best I can say, is if they were closer to me, I wouldn't hesitate to give them a go. But I'd hate to have to drive there for follow up work, and you're even farther away. Anyway, they are absolutely worth a call for a phone interview to see if they pass the smell test, if you're not getting traction anywhere else.


(if you go, let them know they were doing the right thing to get the GLA into dyno mode, you just have to nail the button timing perfect or it won't work :) )
 
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