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W212 OM642 231 horse version...boost pressure gauge.

ALFAitalia

MB Enthusiast
Joined
Feb 19, 2022
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9,218
Location
Bognor Regis
Car
2010 Mercedes W212 E Class E350 CDI Sport, 2006 Mercedes W169 A Class A170.
Having had a turbo fail I'd like to be able to see the boost pressure while I'm driving (and to see changes in boost with any possible future tuning) . Yes I can do it with my phone and my torque app....but that's a pain and needs to log on and set it up each time I drive etc. So a permanent gauge would be better. Equally however I don't want to look a drag strip/F and F reject!....so no gauge on the dash in a pod naffness!
I assumed (being old skool....or just old!) that I would be taking a feed from the factory turbo boost sensor or a vacuum point on the inlet manifold......but having looked for a subtle digital boost gauge I noticed that lots run from the obd port....many wirelessly through the same sort of dingle I use for my torque app..... thats much simpler and no wires to run through to the engine bay.
Anyone done it? Any good? Recommended gauges? I'd prefer thin and digital for easy placement rather than the hard to place 60mm gauges. I look forward to your responses...and p155 taking knowing you lot!.....both welcome!
 
Anyone? There must be a take off point I can use somewhere without getting the drill out!
 
Have you ever used an Arduino or similar microcontroller before? Or if you're happy to learn, plenty of to tutorials on YouTube for gauges and querying PIDs on OBD.
 
I'm going analogue, with a digital display....so I just need a point , preferably a pipe that sees the boost, that I can tee into for the pressure sensor.
 
I'm going analogue, with a digital display....so I just need a point , preferably a pipe that sees the boost, that I can tee into for the pressure sensor.

Follow the pipes from the turbo actuator, it's possibly got t's along it's length somewhere. Mayswell fit a manual boost controller if your going to the trouble. The gains are incredible along with the turbo blanket. 👍 . I fitted one to my Toyota Celica gt4 ran it at 16 psi iirc ?? Stock was around 11 psi.


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I dont think I'll be tuning this one (first car in ages TBH)....its go enough go for me, for now at least....I dont think tuning a 90 plus thousand mile cars is the best idea!! Unlike my 159 it just does not seem like the sort of car you need to bomb around in to enjoy. Do those boost controller things actually do anything?....cant imagine they do!!
 
I dont think I'll be tuning this one (first car in ages TBH)....its go enough go for me, for now at least....I dont think tuning a 90 plus thousand mile cars is the best idea!! Unlike my 159 it just does not seem like the sort of car you need to bomb around in to enjoy. Do those boost controller things actually do anything?....cant imagine they do!!
Yeah they let you control the boost , believe it or not 😜. If you understand how a waste gate works ,would help.

Why do you want to know boost pressures for then , and fitting turbo blankets , just leave it a bee 🐝 🐝. 😁😁
 
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Om642 turbos don't really have a waste gate what with being a variable geometry turbo.
I mainly want to know the boost levels out of curiosity......and to give warning of future issues.
 
Om642 turbos don't really have a waste gate what with being a variable geometry turbo.
I mainly want to know the boost levels out of curiosity......and to give warning of future issues.

2 totally different things , I'll leave it there . Hope Google finds you a boost pipe 😀
 
Variable Geometry Turbos don't have a wastegate that regulates the exhaust flow. A VGT more accurately controls the air-to-fuel ratio, allowing for more horsepower. The vanes inside a VGT are what allow you to maximize your boost at a much greater RPM far better than a wastegate.
There was certainly no wastegate on my turbo I recently replaced.
 
Variable Geometry Turbos don't have a wastegate that regulates the exhaust flow. A VGT more accurately controls the air-to-fuel ratio, allowing for more horsepower. The vanes inside a VGT are what allow you to maximize your boost at a much greater RPM far better than a wastegate.
There was certainly no wastegate on my turbo I recently replaced.

Think that's the electronic actuators job ?
 
To control the variable Geometry?... then yes.
 
Log on to Torque each time?
I use the pro version and once I initiate the app, on my Android HU, it links to the BT transmitter and populates the app.
Admittedly it can be hit and miss, down to the app the sender or the Chinese Android I don't know.

For me though, to monitor engine sensors that's better than anything else I've heard of. As really, once I am familiar with what I might be expecting from them, to just look in occasionally is good enough.
But I do watch more closely for exhaust temp to rise as I'm expecting a regen, I'm paranoid about that.

T'other day it did diagnose the MAF as u/s when it went limp, I confirmed with my DVM. If lucky that'll arrive today.
 
Yeah....I do have Torque Pro......but sometimes I forget to put my phone in the holder for the maps....let alone boost readings!!
 
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