question about backpressure and sidepipes...

it feels a bit slower because you killed most of your backpressure i once wanted to run side pipes but decided not to due to the lack of back pressure.

P.s. those 3" pipes arnts helping either.

ya but............. you never stated that above a 351 would do fine with 3" but mufflers are needed to keep up the back pressure.

real common misconception.. backpressure is BAD. exhaust velocity is GOOD. Exhaust is tuned on motor output. a car with a low cam, torquey manifolds, small tube headers, etc. are best suited with a smaller pipe. This lets the exhaust have good scavenging in those RPMS. thast why a stock system makes good torque in most scenarios with smaller pipes. When people go to headers, they complain of loss in low end. However, this increses the efficiency in the upper RPMS.. which is why with breathing modifications you get more power up top.
If you were to match your 3 inch pipes with a victor manifold, a x cam, etc the car wuold absolutely fly (assuming you had the headers to match) and pull higher RPMS.. where it is pushing more air and scavenging would be present in those RPMs
If you dont have a lot done to a motor.. smaller pipe is best.. if you have things that increase airflow, its better to go up in size. a majorly upgraded motor will require that big pipe.
backpressure is bad. plain and simple. it causes a pumping loss. instead of scavenging and pulling gasses out, it takes power from firing cylinders to push the gas out of the pipe. However, this smaller pipe will probably make more low end torque.. so it will feel faster to an extent from throttle response. however quarter mile times will prove you wrong. Hope i cleared this up. DONT go sticking a potato in your exhaust for some pressure
straight through mufflers are great.. straight through mufflers with 3 1/2 inch openings arent that great. all about balance.