Actual boost VS Requested boost

[imported_SYNAPS3]

Hi
Below is part of a log from my Revo S3.
My actual boost is not meeting the requested boost /ubbthreads/images/graemlins/mad.gif.
What are the possible causes:
Is my turbo not capable of producing this boost?
Could i have a boost leak?
What else.....
How can i go about trouble shooting....

Group A: '115
Engine Speed Load Cmd Pressure Press @ Intercool
TIME
Marker STAMP /min % mbar mbar
19.42 2600 130.8 2150 1630
19.73 2680 136.8 2180 1700
20.02 2760 143.6 2230 1790
20.33 2840 148.9 2280 1880
20.63 2920 158.6 2300 1980
20.93 3040 169.2 2310 2090
21.23 3120 177.4 2340 2190
21.54 3240 182.7 2360 2250
21.84 3320 185 2380 2300
22.14 3400 183.5 2400 2270
22.44 3520 181.2 2420 2280
22.74 3600 180.5 2430 2250
23.04 3720 180.5 2420 2280
23.35 3800 178.9 2430 2260
23.65 3880 180.5 2420 2250
23.95 4000 178.2 2430 2250
24.25 4080 176.7 2410 2250
24.55 4160 179.7 2390 2220
24.86 4280 175.2 2370 2220
25.16 4360 176.7 2340 2190
25.46 4440 172.9 2310 2150
25.76 4520 173.7 2300 2110
26.06 4600 169.2 2240 2100
26.36 4680 169.9 2220 2090
26.66 4760 166.2 2200 2070
26.97 4840 163.9 2160 2050
27.27 4920 163.2 2150 2020
27.57 4960 163.2 2120 2000
27.87 5040 162.4 2090 1960
28.17 5120 157.9 2070 1970
28.47 5200 157.9 2040 1940

 

[DavidR]

Air Mass Sensor problem or boost leak are the most likely culprits in the S3.

 

[NWMark]

Id say a boost leak also, you sometimes get a very small shortfall from requested to actual but its not usually as big as 0.2bar.

Make sure all the pipes are nice and tight.

might also be the diverter valve, with a dodgy diaphragm.

Mark

 

[imported_SYNAPS3]

Thanks Mark
Does anyone do their own pressure testing.
How can your test for loss of boost other than making show all pipes are tight.

 

[darko]

just going to get mine checked this weekend, have you noticed the turbo being noisier than normal ? that is the reason im getting mine checked plus the performance seems to tail off too soon...