Req Vs Actual Boost log - Figures don't match up at all! (Boost leak?)

[gex18]

As per the title really, my MK4 Ibiza Cupra struggles to maintain boost, and performs poorly on the dyno, so thought a VAGcom log of requested vs Actual would be able to confirm if there was a boost issue, results below - any ideas? Boost leak?

RPM Req Actual

2120 2110.0 1500.0
2200 2130.0 1570.0
2240 2150.0 1640.0
2320 2180.0 1710.0
2360 2220.0 1760.0
2440 2240.0 1820.0
2520 2270.0 1880.0
2600 2250.0 1940.0
2680 2270.0 1990.0
2760 2270.0 2040.0
2840 2270.0 2120.0
2920 2260.0 2170.0
3000 2250.0 2230.0
3080 2230.0 2260.0
3200 2200.0 2330.0
3280 2200.0 2290.0
3360 2200.0 2220.0
3440 2180.0 2160.0
3560 2180.0 2130.0
3640 2180.0 2140.0
3720 2170.0 2140.0
3800 2180.0 2110.0
3880 2150.0 2110.0
3960 2170.0 2100.0
4040 2160.0 2130.0
4120 2140.0 2100.0
4200 2120.0 2050.0
4320 2110.0 2070.0
4360 2090.0 2070.0
4440 2080.0 2010.0
4520 2070.0 2020.0
4600 2060.0 2010.0
4680 2030.0 1950.0
4760, 2010.0 1960.0
4800 1980.0 1920.0
4880 1960.0 1900.0
4920, 1930.0 1900.0
5000, 1910.0 1860.0
5080 1900.0 1850.0
5120 1900.0 1840.0
5160 1890.0 1800.0
5240 1880.0 1810.0
5280 1870.0 1800.0
5360 1860.0 1750.0
5400 1850.0 1770.0
5440 1840.0 1750.0
5520 1830.0 1710.0
5560 1830.0 1750.0
5600 1820.0 1730.0
5640 1820.0 1720.0
5680 1810.0 1700.0
5720 1810.0 1670.0
5760 1810.0 1670.0
5800 1800.0 1650.0
5840 1800.0 1690.0
5880 1800.0 1650.0
5920 1800.0 1670.0
5960 1790.0 1640.0
6000 1790.0 1650.0
6040 1780.0 1670.0
6080 1770.0 1670.0
6080 1770.0 1640.0
6120 1760.0 1630.0
6160 1760.0 1590.0
6200 1760.0 1610.0
6200 1760.0 1610.0
6240 1750.0 1600.0
6280 1750.0 1620.0
6280 1750.0 1620.0
6320 1750.0 1610.0
6320 1740.0 1610.0
6360 1740.0 1610.0
6400 1740.0 1620.0
6400 1740.0 1600.0
6440 1730.0 1570.0
6440 1730.0 1600.0
6480 1720.0 1580.0
6520 1720.0 1600.0
6520 1720.0 1610.0
6560 1720.0 1620.0
6560 1720.0 1610.0
6600 1710.0 1580.0
6600 1710.0 1570.0

Many thanks

Anthony

 

[Ferryman]

I am no expert but can´t quite see whats the problem?

From 3000rpm to 5000rpm requested and actual boost are quite well aligned.
Above 5000rpm the turbo runs out of breath as expected (with K03S).

You can check the N75 solenoid if you like.
Unplug the connector and measure the resistance between the two contacts.

If the resistance is between 25 and 35 ohm, the N75 is fine.
Otherwise replace the part.

 

[gex18]

I am no expert but can´t quite see whats the problem?

From 3000rpm to 5000rpm requested and actual boost are quite well aligned.
Above 5000rpm the turbo runs out of breath as expected (with K03S).

You can check the N75 solenoid if you like.
Unplug the connector and measure the resistance between the two contacts.

If the resistance is between 25 and 35 ohm, the N75 is fine.
Otherwise replace the part.

The problem is that requested and actual are never the same at any point in the RPM range - with boost tailing off very early for a K03s - which as I understood should hold well above 1 BAR to 5500?

The N75 is new, and was replaced 4 weeks back, the resistance is fine.

Would a boost leak be too obvious? I have checked all the obvious hoses in the engine bay and found nothing split / loose - there is an apparent whistling / hissing noise when the turbo is spooling up though?

 

[Ferryman]

Which N75 did you use btw?
Revision.

 

[DannyC87]

graphed it for you - can't see any problem with this; actual is within allowed deviation of requested.

 

[gex18]

graphed it for you - can't see any problem with this; actual is within allowed deviation of requested.

Cheers for the graph

For some reason the ECU is only requesting 0.91 bar @ 5k - which is quite low for saying its a Revo Stage 1 map isn't it?

 

[gex18]

Which N75 did you use btw?
Revision.

I forget the code now, but its the same code as the one I replaced - im sure its 'F'.

 

[DannyC87]

what boost setting is your revo set to?

 

[gex18]

what boost setting is your revo set to?

When the settings were acquired from the ECU it was set to 9, it is now set to 6 as per Revos recommendations.