im putting a cut out on tomarrow how much will i notice in hp gain with it open over with it closed and just flowmaster muffler?

 

I really did not feel a gain in the butt dyno, but it sure does sound a lot faster

 

My car picked up ~45rwhp and ~40rwtq through my cutout over my Flowmaster when that's what I had on the car. It showed at the track too, if I ran capped and then uncapped when I uncapped the car it would drop .4 and pick up 4mph. But I am sure that is not the norm. Even when my car was basically stock it would drop ~.2 and pick up ~2mph.

 

on my lt1 i did not notice any types of gains did seem to loss same low end tq. my cat-back is flowmaster so i am sure i had hp gains but again i was not able to tell.

 

ok thanks