M275 65 AMG Stock boost pressure




I have tried searching for this info, but come across conflicting results.
Some posts on here say 1.5 bar (21 psi)
M275 training document says 1.9 bar (27 PSI) (that cant be right).
I am seeing a max in midrange of 17.5 psi on my S65 AMG (221).
Can anybody confirm what its meant to be?




So I am not making the right amount of boost. Air filters are new. IAT's under 70 deg c (bleed temp), around 25-35 above ambient on the motorway.
I assume things to check are, vaccum leaks to the actuator/turbos and boost leaks in the air inlet system?
Last edited by alexanderfoti; Nov 2, 2016 at 03:17 PM.




I believe the first place to look would be at the hose joints on the turbo outlets and IC inlets.
Do you get any noises, errors or misfires when you hit max torque / middle revs?
Nick
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I will double check those clamps etc, and possibly replace them with larger ones.
I will also do so me data logging rather than just looking at the display whilst driving....


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Then I replaced the IC inlet hose clips with much sturdier T-bolt clamps, and the misfire went away, and the engine would accept WOT all day.

Then the gearbox broke .....

Nick
Last edited by Welwynnick; Nov 3, 2016 at 03:03 PM.




Edit: EPC shows different part numbers, maybe that's the case?
Last edited by alexanderfoti; Nov 4, 2016 at 04:40 AM.
65 stock has significantly more boost than 600 stock. 600 was detuned for the markets to have same power output like the SL55.
With tuned ECU you can drive a little more boost in the 65 over the 600, because of the bigger Turbine wheels. But there is not much difference. The Black Series 65 has also bigger turbine housing and wheels and this makes more of a difference.




65 stock has significantly more boost than 600 stock. 600 was detuned for the markets to have same power output like the SL55.
With tuned ECU you can drive a little more boost in the 65 over the 600, because of the bigger Turbine wheels. But there is not much difference. The Black Series 65 has also bigger turbine housing and wheels and this makes more of a difference.
M275 - 65 AMG - More boost then M275 600 and tuneable for more boost due to bigger turbine wheels
M275 600 - less boost stock of all, and not capable of as much boost as the 65 turbos?
And
17.5 psi is adequate for the M275 E60? I am hearing MAX tune should not be higher than 21psi?
Today it's about 25'C outside and intake at 17,5 PSI was ~47'C on 100% load 4th gear from low rpm to end.
It's normal or I must to find the problem why it's not 21 PSI ?
Read via OBD port + application Torque PRO ( perfect app )
Last edited by HgoAMG; Jun 2, 2018 at 11:31 AM.




Today it's about 25'C outside and intake at 17,5 PSI was ~47'C on 100% load 4th gear from low rpm to end.
It's normal or I must to find the problem why it's not 21 PSI ?
Read via OBD port + application Torque PRO ( perfect app )
I made test 5 min ago ( in night 14'C outside ) and also get 18 psi at about 33'C Intake ( A/C off- it drop few 'C intake without A/C ).
Damn that car is really fast in stock I can't waiting for new mods and about 700 HP

After changing tyres to new Pilot Sport 4S it really start kicking in back
Last edited by HgoAMG; Jun 2, 2018 at 06:44 PM.
I made test 5 min ago ( in night 14'C outside ) and also get 18 psi at about 33'C Intake ( A/C off- it drop few 'C intake without A/C ).
Damn that car is really fast in stock I can't waiting for new mods and about 700 HP

After changing tyres to new Pilot Sport 4S it really start kicking in back

The boost pressure should spike at lower rpm to 21 and then taper off as rpm builds (due to smallish turbine). This is why with upgraded turbos and larger turbines, the system is able to hold 21 psi to redline and yield much better powerband ala sl65 black series.




That is exactly how my mapped 65 behaves.
It likely has to do with when and how the logs were run (roll vs from dead stop and the gear it is in). Stock boost pressure for a 65 is 21 psi and change. The fact that we get lower on logs etc is that the turbos are past their efficiency and cannot maintain boost at those flow rates at upper rpm. Perhaps ESP also controls boost and this has something to do with lack of spike??
I can confirm seeing 21psi without tune during spike and then slow taper down.




I can confirm seeing 21psi without tune during spike and then slow taper down.
The TCU has primary control over torque output and therefore boost pressure control.
Stock you see 18.5 for the majority
Tuned you see 21.5/22 for the majority.
My logs were done on the road, and dyno at various times. Take a look at DUMD'S thread on this SL65 its very informative reading, especially regarding boost pressures.
The TCU has primary control over torque output and therefore boost pressure control.
Stock you see 18.5 for the majority
Tuned you see 21.5/22 for the majority.
My logs were done on the road, and dyno at various times. Take a look at DUMD'S thread on this SL65 its very informative reading, especially regarding boost pressures.
A spike in boost pressure is actual pressure being generated by the turbo and will read on a log. This spike in boost should reach 21.7 and then taper. Here is an article which explains that a system designed with a boost spike will increase low end torque and response and is designed into some stock turbo systems. http://www.turbosmart.com/technical-...ing-explained/
Mercedes Official published "maximum" boost pressure for m275 E60 is 1.5 bar (i.e. roughly 21.8 psi). In this case, the spike is actually the maximum boost pressure you should see stock which then tapers down after 3500 rpm. If that were not being registered than either (1) the car is not running 100% perfectly or (2) the datalogger is lagging and not capturing the data perfectly. After replacing every single component in the boost control system, I can see many areas for failure here which is why given the relatively cheap cost for new components I went ahead and replaced everything.
I do wonder whether the traction system could be a culprit given its integration with the whole ecu and tcu.
Cheers




Where are you reading this "official Mercedes published value". I am relaying my personal experience with this platform.
The boost spikes at 4k rpm, it is not mapped to spike .




