It seems like ever since I replaced my cat converter with a straight pipe, I lost power, or take off speed. Not to mention my exhaust now sounds like crap from the outside of my car. Took bad advice from muffler shop, the guy said my 3.4L would sound "mean" with an 80-series Flowmaster muffler without a catalytic converter . As a result, it seems as though I lost some torque in the process and gained a crappy sound . By the way, I have an automatic transmission. Is doing that true as far as my torque goes? Any suggestions? Please help me out ASAP !!!
Thanks you guys
4 More Years !!!

 

Your engine needs backpressure to work efficiently...if anything, you moved your torque range higher which is why it feels sluggish at lower RPMs. It probably pulls harder up top though, right?

Really, the guys who benefit most from that sort of setup are guys with turbo or supercharged applications. Not really for us.

 

Import is right. Back pressure effects where your torque peak is, and if you have a high torque peak, you're not going to have the low end you want. If you don't like how your car is performing now, maybe try replacing the straight pipe with a cat of some kind. That will increase your back pressure, and give you some of your low end torque back.

 

I replaced my cat with a straight pipe car felt quicker to me but then again i have a stick, and u should have got an 40 series instead imo.

 

Back pressure doesn't make or loose power. But yes. your TQ band has shifted and you have probably gained some high end grunt. It;s all the theory of volume, scavenging and volocity etc that will efeect the power band. But truely if you want power.. you need less backpresser.