Catted downpipes and reduced boost ?!?

[bee615]

Hey guys,

Just installed a set of Livernois catted downpipes yesterday and loaded up the revised Torrie tune.

I think I am actually seeing less boost at part throttle in the lower gears then before but the car certainly pulls harder say from 40-50 mph.  Checked for leaks and all looks good.

Is this something anyone else has encountered or I am imagining it?

Thanks.

[glock-coma]

I can't be sure but you probably need less boost pressure for the same amount of power due to the higher flow   Downpipes.

[FoMoCoSHO]

Yup, you just got a bump in efficiency...same reason cutouts make more power on same boost levels.