VW Jetta 1.9 TDI ALH

by **rowly747** » Mon Aug 19, 2013 8:30 pm

Increase the n75 map to stop boost spikes. You do this by using your logs and for the IQ injected and the rpm increase the value. Check your boost limiter isn't set too much above requested usually 50mbar is enough. Also if you still get overboost physically adjusting the actuator will do the trick

by **fanvw** » Mon Aug 19, 2013 8:44 pm

so all i need to do is to increase duty cicle on N75 map @ 2100 RPM till 2300 RPM...and after (if this doesn't do the trick) i will adjust (mechanical) the actuator

by **rowly747** » Mon Aug 19, 2013 8:52 pm

Yes increase n75 map by say 2% and log again and then go from there

by **fanvw** » Mon Aug 19, 2013 9:04 pm

so i will try to increase only the values that i've selected and see how it works

by **rowly747** » Mon Aug 19, 2013 9:32 pm

Look at your logs. Your not meeting request at some points so lower the value to increase boost and increase the n75 map to lower boost.Your logs show over boost upto 2750rpm so you need to increase for all affected rpms. So that specified boost = actual. But also as mentioned before boost limit map should only be about 50mbar higher than requested boost. So if requesting 2130mbar set limit map too 2180mbar. This will cut boost earlier so as to avoid huge boost spikes as well.

by **fanvw** » Mon Aug 19, 2013 10:36 pm

i usualy keep boost limiter @ 2150 mbar but i think that i forgot it @ 2500 mbar...first,i'll try tomorow to read my ecu and to see what value i have on boost limiter map...thanks anyway,you are a great guy because you are willing to share your knowledge :D

by **fanvw** » Thu Sep 19, 2013 9:10 pm

Q: is there any EXCELL sheet that can help me with the values of N75? or the only solution is to experiment until i reach the balance between actual boost and specified boost?

by **trevor** » Sat Sep 21, 2013 5:24 pm

USe SOI maps this engine can work with similar power and torque with consumption below 6 l/100km .

by **rowly747** » Mon Sep 23, 2013 10:43 am

fanvw wrote:Q: is there any EXCELL sheet that can help me with the values of N75? or the only solution is to experiment until i reach the balance between actual boost and specified boost?

You simply have to try. If you don't want to risk spiking the turbo too much when testing increase map at the affected areas by a big amount say 5% then decrease till you get near enough boost specificed. It is all trial and error