ok so i had stock manifolds cats to a magnaflow x pipe to magnaflow mufflers. the person b4 me added cut outs b4 mufflers an i been running them open for the last few months no problem. heres where my torque problem is i just did obx long tubes no cats magnaflow x pipe cut outs open an when i shift it doesnt pull like it use to an i been noticing it. so runnign straight pipes did i lose back pressure losing torque??? had car dyno all stock besides fullexhaust an basic tune 351.64rwhp 344.64rwt
Back pressure doesn't create torque. You probably have more torque, but at a little higher RPM so it doesn't feel as torquey, but it is faster. I'll give you a personal example. My 00 SS had true duals. I had it flanged so I could run them dumped or out the back. With the back section on it felt like it pulled harder, but without it the car would consistantly run .2 sec quicker ET's in the 1/8 mile.
Buttdynos are notoriously inaccurate and I'd rather have a faster car than one that feels faster but runs slower.