Engine braking power

[808allstarr]

Is there any difference in engine braking power when egr valve is open or closed? And has anyone have any opinions on braking power of cm870 vs 871? Trucks specd more or less the same only difference is 870 vs 871 but i driven both many times and seems like 871 slows down alot better with same loads on same hills.

[Running rough]

Difference is 871 has electric Vgt actuater vs 870 with an air controled actuater, they are both controled by the ECM but the 871 electric has way faster response time, in other words the turbo can close or open faster giving it better jaking and or faster spool up