cat no more

[hotshotzny]

i am removing my cat from my 84 and installing a test pipe.. ive had some advice on the procedure and im not doubting it but im just curious what others have done concerning the AIR pump/hose going to the stock converter.... i dont want to fudge anythng up

 

[vetteric2]

i dont have an 84 but the exhaust is sort of similar from that section but i did straight pipes all the way back with no test pipe and it runs good. i also modifided my manifolds so they dont have the air injection on them anymore. hope that may help.

 

[green 84]

What is the difference between test pipe and straight pipe??

 

[nelson84]

They call it a test pipe meaning you are testing your performance at the track and will put the cat back on for street use. It just sounds better than straight pipe( for the hippies and tree huggers). It is the same thing. It is the easiest mod and for the 15 minutes it takes to replace is the best bang for the buck, besides porting your intake manifold.

 

[vetteric2]

that's not 100 percent true i have a pipe for each side of my exhaust going straight back with no converters where a test pipe will go in place of an exhaust that is meant for converters.

 

[nelson84]

It is a straight pipe going from the front y pipe to the rear y pipe. You are confusing straight pipe with dual straight pipes(pipes with an "s"). This test pipe is better if you want to keep it stock looking and can easily be reversed. Dual straight pipes will give you less back pressure and a little more performance but will cost you a lot more than $50.

Test pipe= 10-15 hp

dual straight pipes = 18-25 hp

 

[CorvetteArchives]

I still think the smartest thing to do is hollow out the cat if one was so inclined to pass a visual inspection. Not having any experience with this...would it resonate? And would it then be wise to put a str8 pipe inside?