JRad405

The title is basically my questions. It was posted on another forum I'm on but it actually got me thinking. And since Cliffyk and some other guys on here are pretty technical, I figured I would ask.

So does anyone know how do hi flow cats work? Are they really hi flow?


Note: This isn't to bash hi flow cats being that I have them on my car. Purely an informative question.

Rockwell28

the holes in the ceramic material are quite larger than the ones in the factory cats so hi flo cats are basicly cats that want meet the factory standards so the exhaust does flow through them easier than th factory cats bc of the lack of material inside the hi flow cats. So hi flow cats do the same job as factory cats as far as cleaning up you exhaust it just doesnt do as nearly as a good job at it vs the factory cats.

JRad405

I see. But I guess depending on where you live you may pass emissions with hi flow or you may have to have factory cats.

My year I know has 6 cats, so I'm not sure what they wanted when it came from the factory. Seemed more like suffocation.

69MustangCoupe393cid

True statement about the holes, however a lot of "high flow" cats are a smaller diameter than the factory cats, so it all balances out and sometimes factory is better. There are plenty of 03/04 cobras making 600hp with factory cats. That being said I base that on the power of observation haha, not actual data. So maybe someone has some actual flow bench tests?