The exhaust pipe on my project car is in really terible shape and needs to be replaced and I was thinking of leaving out the cat.....if I went a complete straight pipe from my header to my muffler would that effect my engine or my performance...I know nothing about rotaries is why I ask...

 

its nothing but good for power and nothing but bad for the enviroment.

 

It'll help with power but the car will become pretty loud and a tree killer. But thats alright. Go mid-pipes.