just me

iTrader: (3)

I had my car mapped to 1.65 bar boost on a billet 321t, however my boost gauge consistently shows a fraction under 2 bar peak.

I have checked for splits in all the hoses at least 6 or 7 times now, double checked the restrictor pill is still present, cleaned it with brake cleaner just in case, half a can of brake cleaner through the bcs, bought a new gauge to eliminate it as possibly over reading, and also had a smoke machine test to check for splits/leaks that are not visible.

Im now at a complete loss as to how to proceed further.

My car has a Ecutek map, I believe the ecu is locked, can logging still be done using open source software?

Have any members experienced a similar issue and how did you resolve it please?

The problem is really starting to do my head in now, the car pulls very well but long term this much boost cant be healthy for a standard engine.

MartynJ

What gauges are you using as Defi gauges for instance are prone to over read.

just me

iTrader: (3)

Sorry I should have said, My gauges are Depo branded, as far as Im aware its the same factory as Prosport.

Up to 1.5 bar the gauge does correlate to the reading given by Torque app which uses the map sensor.

JamesDundee

iTrader: (2)

Maybe get the gauge tested mate?

just me

iTrader: (3)

Thanks mate, its a brand new gauge, although same make as the old one.

JohnD

iTrader: (5)

You would certainly feel the difference in performance between 1.65 and just under 2bar. Does it feel livelier? After re-setting the actuator pre-load on my MDX321T I got overboost (from 1.65 to 1.78bar) and could certainly feel the difference. Luckily adjustment of the boost duty on the AVC-R brought it back.

JohnD

just me

iTrader: (3)

Thanks for the advice John, can I ask how exactly do you adjust the preload, I have some blue paint on the actuator arm and the nut, I assumed Turbo Dynamics put it there.

I assume I would need to loosen the nut, but then what?

The car feels amazing to drive, it is definately lively, I just dont think the standard engine can cope with 2 bar?

Although it would be great if it could.

Just to add, I have a turbo blanket which I mounted underneath the actuator arm, could this be obstructing movement? Nothing was apparent during the map.

The arm itself does not seem to move easily by hand, again I assumed this was normal?

Shaun

Don't adjust preload unless you know what you're doing.

Best to get it checked with a confirmed gauge first.

just me

iTrader: (3)

I wont touch it then, can a Ecutek mapped car be logged by somebody other than the mapper using other software?

If its possible I would like to do a few full boost runs and check if the boost matches the gauges. Torque app wont read more than 1.55 bar due to map sensor/ecu issues.

Shaun

In most cases you'll need to use a calibrated or known quantity boost gauge.

If you take it to a rolling road, you'll get a better idea as they will have the equipment / sensors to check whilst completing a power run.

Also worth getting in touch with whoever mapped it.

Circa .35 bar is quite some over read for any boost gauge. Defi's over read by about .1 bar.

The reason you shouldn't "just" adjust the preload, is that you'll run the risk of your boost map going to whack with the adjusted preload changes.

In any case, unless the actuator has been changed since the mapping took place, it will be set as per map expectations. Preloads can weaken (you'd lose boost) over time not the other way round.

JDM_Stig

iTrader: (3)

You could whip the blanket off and try it,
Quick and easy test

just me

iTrader: (3)

Shaun, many thanks for the reply, my first thought was to take the car to a dyno, but the nearest one is fully booked till the middle of april.

Out of curiosity, what is the likely outcome if I did drive the car with this much boost ( I havent used full boost regularly)?

just me

iTrader: (3)

Just tried it, still doesnt move lol

Shaun

It could be running lean when you're moving past the mapped boost. Not good!

It's not good to be running past the MAP sensor limit (as you seem to be, even as part of your remap), as your ECU can't adjust past this point, if your MAP scale has not been rescaled to cope. It also means you'll have no boost cut protection, which isn't a great idea tbh.

Who mapped it?

BrownPantsRacing

iTrader: (6)

I would want to change the boost map sensor for a larger range version to start with. It may work outside its calibrated range and max quoted range but certainly not advisable.

Shaun

There are ways to rescale the existing sensor scale. You don't always need to buy a new sensor.

TimH

iTrader: (11)

I don't believe you can rescale the sensor...a 2.65 bar MAP sensor will always be a 2.65 bar MAP sensor giving, typically, 0.5V at 0 bar and 4.5V at 2.65Bar (for example).

Outside of the linear range (0.5-4.5V, typically) you cannot rely on the readings, unless, I suppose, you calibrate a specific example of a sensor against a known-good wider range sensor. You might get another 0.1 or 0.2 bar out of it, but probably non-linear in that range.

If the ECU is artificially restricting the range available, that's a different matter of course.

BrownPantsRacing

iTrader: (6)

Tim I completely agree with all of your statement above, as I actually design electronic measurement sensors and systems for a living. I know what Shaun is saying about recalibrating the system but the only sure fire way would be to test the sensor over its extended non linear range and adjust the ECU feedback (sensor input) to look at the actual voltage readings coming back over that range. Not sure you can do this in the ECU.

You can not guarantee the sensor output is still linear or accurate past its calibrated range limits, or it may not actually be able to sense that high by design.

Shaun

You can rescale how the ECU interprets what the MAP & MAF sensors are providing the ECU. Both of those have been rescaled on my OEM ECU and I'm certainly not the first.

Obviously there are boundaries to this.

BrownPantsRacing

iTrader: (6)

I'm not questioning that although not good practice it can and has be done on occasions. I would be very interested to find out exactly how it was done in practice. Making a sensor work accurately past it's design and calibration limits is interesting.

Shaun

MAF is somewhat different in reality, as it's the airflow being rescaled at the same sensor voltage.

My MAP sensor pressure reading has been rescaled to read about .2 bar below what it actually reads, but only to allow slightly more headroom, as I'm close to the map sensor limit. This allows adequate control for boost cut in the range when running close to what the sensor can accurately read.

Like I said, there are limits as I'm not suggesting you'd run 3bar on a 2.5bar map sensor for instance.

BrownPantsRacing

iTrader: (6)

Understand what you are saying but it's not ideal. Basically it's adding an offset in the software to shift the entire range without changing the slope of the linear output and sensor calibration itself. However it doesn't really change the fact that the sensor itself can only read up to a certain pressure, or will only be calibrated over a certain pressure range at very least. As you say, it can't make a 1.6 bar sensor into a 2 bar sensor magically.

Even with an offset added in the software for the MAP sensor to try fool the ECU, it may still be the case that the OPs MAP sensor is reaching it's limit and causing overboosting.

Shaun

Agreed and as I don't know enough about the real range the OP's MAP sensor, or how any rescale may have been adopted in his map, I wouldn't make any assumptions as to what the OP can or cannot do on his set-up.

All I would say, is that if the MAP range has been ignored and the OP is in fact achieving the boost targets he is suggesting (with no apparent ecu control)...... I'd be sorting it out pretty sharpish.

BrownPantsRacing

iTrader: (6)

Totally agree!