So I just got my engine and trans back into my 35th anniversary 350z, and wanted to know if it could damage my car to run open test pipes with no cat-back exhaust. Would this be okay? What should I expect?

 

A whole lot of noise and exhaust gas possibly coming into the cabin.

 

the noise is no issue, I want the car to be loud, it’s not a daily. As for the exhaust gas, I guess I could just try for a while and see what happens, I don’t see how no cat-back could hurt the car.

 

It won't hurt the car

 

You're not going to hurt the car. You might hurt your ears. With the exhaust exits underneath you, it is going to be obnoxiously loud and likely shake everything - like really loud. If you want to keep the exhaust as unrestricted as possible but keep your hearing, just run some straight pipes with no resonators directly from the TPs out the back.

You should do it, though, and post a video while you're at it. I'm curious what that's going to sound like.

 

if you just run open headers, i would at least put some kind of turn down so you dont have hot gases blowing directly at the cabin

 

Here’s a video I found on YouTube that sparked the idea in the first place, and man, it sure is loud!

 

reminds me of this

 

haha
i think the test pipes sound better than a straight pipe 350z, those straight pipes sound awful in my opinion

 

One other point to make is while it may not damage your Z, running test pipes and nothing else will not help with exhaust scavenging. That'll likely result in a loss of horsepower and torque and you could end up throwing a CEL. Your choice...