Technical T-Jet Fluctuating Boost Pressure

[JackFi]

Yah... that is what i'm seeing. no fluctuation, no boost cut (can see that in throttle angle).

-Depending on the boost gauge sampling rate you might be loosing some data ...so the reason you're not seeing the same boost levels.
-The boost gauge might just not be very well calibrated.


Is the DeltaT in seconds? so 10-12 seconds to get full boost? that's not great, BUT depends at what rpm you start at. For example: if you start at 2000rpm, it will take much longer than if you start at 3000rpm.
-RPM and Vehicle Speed would help; So a few runs with what you have selected now, and a few with "Intake manifold pressure", "RPM" and "Vehicle speed".

I'd suspect the boost gauge/sensor: electrical connections (so worse when engine is bouncing about under load); or maybe it's just bad.
You could try fitting a restrictor in the hose to the sensor; the smaller hole will act like a capacitor on an electrical circuit.. it will smooth out the pressure to the sensor.


Was the gauge acting up while you were taking these graphs?

With regards to the boost gauge, it’s always worked spot on, it has a restrictor fitted, I’m guessing the sensor could be faulty and the full boost not registering correctly.

Ahh yes the readings were taken from 1000rpm to roughly 4000-4500 in 4th gear, that’s why there is so much lag.

I will (hopefully today) get a few more runs. The gauge was acting up during the runs, the needle was going up & down as previously described, I still need to show a video of this.

 

[JackFi]

Just a quick update, I have ordered a new sensor for my boost gauge, hopefully that is the issue but I will do some more MES runs soon.

 

[JackFi]

UPDATE! I replaced the sensor but made no difference, I replaced the boost/vacuum line and noticed the line had got caught under the suspension top hat but and had been crushed and split the line. All replaced now with a silicone line and out the way of the suspension, now it’s working perfect & driving normal too. I can’t believe it was just that, I’ve had this problem since August last year, I even replaced the line that goes the from the inlet manifold to the fuel reg but didn’t think to replace it to the gauge as the line looked fine and did realise to was trapped. Thanks aurick86 for your help with MES, I think I will do some runs soon to make sure everything is 100%.

 

[JackFi]

The offending item!

 

[aurick86]

OK, so now find another place to take the boost reference off.
Where do you have the sensor? why do you need so much line?
Put the sensor somewhere close to the source... zip-tie it?

 

[JackFi]

OK, so now find another place to take the boost reference off.
Where do you have the sensor? why do you need so much line?
Put the sensor somewhere close to the source... zip-tie it?

It should be fine now but yeah it’s not the best place I know as it could of caused worst issues.

The sensor isn’t waterproof/weatherproof but I could buy a weatherproof one and extend the wiring. I find it strange how to got caught under the top of the suspension, I only realised after trying to pull it out after disconnecting it. The hole is quite big so I’m surprised it showed any pressure on the gauge.

 

[edesl]

Anytime you measure boost pressure with MES, put the desired intake pressure parameter onto the graph as well.
That shows exactly if the boost pressure is in line with the "needs" or not.