Well peoples.... Results from the evening work...
I have done the N75C/MBC parallel installation this evening, as I had feck all else to do....
Anyway, easy enough to do in fairness - diagram below:
Got the idea from Tuffty who has been having the same driveability issues as me. The turbo trying to achieve full boost all the time kills MPG really badly, as well as giving a lot of compressor stall mid throttle which isn't the best.
Anyway, did some logs before and after. Will take photos of the install during the light tomorrow - it's a bit dark out there at the moment.
Before logs:
Code:
Monday 13 December 2010 18:49:08
8L0 906 018 N 1.8L R4/5VT G 0002
Group A: '002 Group B: '020 Group C: '115
RPM Load Inj. On Time Mass Flow Idle Stabilization Idle Stabilization Idle Stabilization Idle Stabilization RPM Load Absolute Pres. Absolute Pres.
TIME TIME TIME
Marker STAMP /min % ms g/s STAMP CF CF CF CF STAMP /min % mbar mbar
143.4 2240 39.8 2.87 16.11 143.89 0 0 0 0 142.99 2200 39.8 1010 1060
144.79 2240 39.8 2.87 16.72 145.19 0 0 0 0 144.39 2240 39.8 1010 1060
145.99 2280 50.4 4.1 25.75 146.39 0 0 0 0 145.6 2240 39.1 1010 1060
147.28 2560 125.6 8.61 65.69 147.7 0 0 0 0 146.9 2440 108.3 2020 1250
148.59 3240 191.7 15.58 143.86 148.99 6 3 3 6 148.1 2920 184.2 2550 1920
149.81 4080 191.7 17.22 186.17 150.29 5.3 2.3 3 5.3 149.39 3800 191.7 2550 2520
151.09 4960 191.7 18.45 225.42 151.49 5.3 2.3 3 6.8 150.69 4720 191.7 2550 2540
152.29 5760 191.7 18.45 252.81 152.78 3.8 2.3 3 6 151.89 5480 191.7 2550 2530
153.7 6520 191.7 17.63 259.67 154.1 2.3 2.3 2.3 3.8 153.3 6320 191.7 2550 2470
154.9 7040 191.7 15.99 268.19 155.41 1.5 1.5 1.5 2.3 154.5 6880 191.7 2550 2440
156.29 7600 185.7 14.76 269.22 156.69 0 0 0 0 155.89 7400 190.2 2550 2470
So... from these the main concern was the timing pull. Over 6's is bad, so I backed the timing down a little after these logs.
After logs:
Code:
Monday 13 December 2010 21:17:24
8L0 906 018 N 1.8L R4/5VT G 0002
Group A: '002 Group B: '020 Group C: '115
RPM Load Inj. On Time Mass Flow Idle Stabilization Idle Stabilization Idle Stabilization Idle Stabilization RPM Load Absolute Pres. Absolute Pres.
TIME TIME TIME
Marker STAMP /min % ms g/s STAMP CF CF CF CF STAMP /min % mbar mbar
296.84 2000 18 1.23 3 297.25 0 0 0 0 296.44 1680 13.5 1710 1030
298.15 2280 35.3 3.28 17.17 298.55 0 0 0 0 297.65 2280 19.5 1010 1040
299.35 2480 95.5 6.15 49.97 299.75 0 0 0 0 298.95 2400 71.4 1010 1070
300.55 2960 191.7 13.94 130.75 300.95 0 0 0 3 300.15 2760 151.9 2550 1580
301.75 3920 191.7 17.63 200 302.18 3 3 3 3 301.35 3560 191.7 2550 2500
303.04 4920 191.7 18.45 227.97 303.56 3 6 3 2.3 302.64 4640 191.7 2550 2540
304.36 5800 191.7 18.45 263.22 304.76 3 5.3 3 2.3 303.96 5560 191.7 2550 2540
305.56 6440 191.7 18.45 267.31 305.96 3 5.3 2.3 2.3 305.16 6240 191.7 2550 2520
306.76 6960 191.7 17.22 275 307.16 2.3 4.5 2.3 2.3 306.36 6800 191.7 2550 2490
307.99 7320 191.7 16.4 275.58 308.34 0 0 0 0 307.54 7200 191.7 2550 2500
From looking at the two side by side, its a surprising result. The N75/MBC combination actually holds boost better at the top end of the rev band. A surprising result to be fair.
Backing the timing down has brought the pull back into reasonable tolerances as well.
Based on this, airflow is up on what it was previously, seeing 269 g/s before the change and 275.5 g/s post change. This is mainly due to the turbo holding boost better towards the top end of the rev band.
Interesting....