The DVs are stock on this NON X50. I think it is what it is so I'll be content not to go making adjustments that when I'm not sure what I am trying to accomplish.

 

Does anyone know if the durametric tool can plot ECU requested boost vs. actual boost? I have seen a lot of these "my car is only pulling 0.x boost... where is my leak?" posts. It is possible that, given certain environmental conditions, the ECU is only requesting .6 bar.
Anyone with a durametric care to fill me in?

 

Not claiming to be a turbo expert, but the ECU does not specifically send a boost request. The ECU controls the components (charge (air/fuel ratio, timing and then we have mechanical WGs). The boost is a function of the pressure built up by the compressor (run by the turbine wheel). The wastegates open to prevent too much pressure being built up, but these are mechanical unless you have installed aftermarket boost controllers. Durametric software does not measure the boost TMK.

 

The tuned ECUs have the capacity to alter the signal being sent to the electronic solenoid attached to the vaccum/boost connections running to the wastegate actuators. The solenoid stays closed longer, thus "hiding" the boost signal to the actuators longer, allowing the wastegate to stay closed longer, creating more boost. As soon as the wastegates "see" the boost, they open and limit the max pressure.

The above is the cleanest way to do things, of course you can put a simple bleeder valve inline to accomplish the same thing by bleeding off some of the signal boost (not reccommended).

 

Interesting... On my S4, using Rosstech's VAG TOOL, it was possible to map requested vs. actual, which was useful in diagnosing boost leaks. If the ECU doesn't control boost levels, and it is purely mechanically driven, how does a flash increase stock boost pressure?

 

You are mis-reading my comments. The ECU controls the components that effect boost...The ECU does not directly control boost....make sense. If I control the pressure, AFR, timing, etc I can change the boost the unit will attain. This is what flashing does. The wastegates are mechanical and some folks put in stronger springs to allow them to hold boost longer than the stock springs (which are of course conservative). You're not driving an audi!

 

I understand it's not an audi, but I would be very surprised if the electronic engine management is terribly different on two MAF based BOSCH ECU KKK turbocharged cars.

I believe jimmer's description of how the N75 valve controls the wastegate opening is the actual reason that boost is increased when a car is flashed. I've been wrong before though.

 

Im .7 when its over 70 or so degrees, and .8 when lower...my car may be putting .8 down all the time though now...not too sure...


01 TT with headers/st8 pipes

 

Yes jimmer's description of an indirect "control" of the wastegate is partially correct as I understand it The wastegate is a mechanical component. The boost is one part of the equation that a flash will affect. Flashing is actually meant to increase power by effect AFRs, timing, etc. It is not just about boost. You can change your wastegate by adjusting the screws on them to increase the clamp..try it. This does not require any remapping of the ECU. Anyway your question was and the answer is no. If you want to check for leaks...do a system pressure test. BTW I was not dissing the audi by any means...great cars...just that the typical diagnostic tools for the audi may not work for a porsche.

cheers

 

Trust me... no offense taken. And I 100% agree that power production is more than just boost, otherwise we'd all just get boost controllers and be done with it. The real reason to pick a flash is how it handles everything else (especially ignition timing). However, I believe the engine sets a boost target that it controls by modulating the N75 electronically. If the ECU is setting this target, I'm surprised that the logging tool can't read it. It can't log actual boost either?

 

There may be a logging tool that does this, but durametric doesn't TMK. This is not unusual as very few folks have access to the Bosch code.

here is the site: Durametric

 

A bit of searching and I turned it up:
https://www.6speedonline.com/forums/...g+boost&page=3
(last post in the thread) Apparently the Revo logger can do it.

This would be helpful for a whole range of diagnostics including assessing momentary boost spikes on spool up, etc.