will runing open header help my et? bc i dont really have a y pipe and it goes in to 2.5in pipe i think

 

I installed a 3" y-pipe on my car to a 3" cutout. Before i had the factory exhaust manifolds, factory y-pipe, and factory catalytic converter, with a 2.5" cat back exhaust from dynomax.


After the headers, 3" ypipe and cutout, the car felt VERY VERY light, with the cutout closed, and even lighter with it open.

So in short, YES! You will notice more torque on the low end.

 

It will only help if you already have a restrictive exhaust system. A good performance exhaust system should make very little difference in your ET except in a weight reducing by removing the exhaust system.

Some of the noisiest cars at the track are the slower ones running open headers. The majority of the fast cars run mufflers including myself.

 

Intex;

Stephen is right. I somehow got the idea you were autocrossing. At the drag strip. open headers is a whole another story, with things like scavenging taking place.

Im one of those noisy slower cars at the moment, but not solely because of the exhaust. Because of the scavenging effect, the difference in ET is not significant between open headers, and corked exhaust on my car right now.

However, you will definately notice a difference in low end torque. Because i opened up my exhaust quite a bit with the 3" y-pipe, this was evident for me on the street.

 

What about running open long tubes?