Question for the experienced

[Inferno]

If I get a set of high-flow cats that have 3" outlets, yet I am putting them on my stock headers and resonators....will I be able to simply clamp them tight without any exhaust leaks, or will I have to get 2 1/2" outlets welded on?

 

[Joseph Dell]

You need to buy reducers that go 3" to 2.5. then you can clamp them on.

Good luck!

JD

 

[Inferno]

You need to buy reducers that go 3" to 2.5. then you can clamp them on.

Good luck!

JD

awesome, I didn't know they made reducers, where do I get them....partsrack?

 

[Schulmann]

Any part store that sells exhaust or summitracing.com

 

[Jack B]

Inferno:

it might not be that easy, you will have to adjust for any deviation in length between the oem and new cat. Do you know that the input to the new cat will fit the oem turnout?

 

[Inferno]

Inferno:

it might not be that easy, you will have to adjust for any deviation in length between the oem and new cat. Do you know that the input to the new cat will fit the oem turnout?

All I know is that they are slightly used roe cats, they were bought with the 2 1/2" inputs/outputs, but the person had a muffler shop weld in a 3" input/output to fit his headers and catbacks. So what do you think? I was hoping the 1/2" wasn't that big a deal, and I was thinking I could slide it over the OEM and clamp it down.

 

[hemibeep]

Trust me, you won't be able to clamp 1/2".
On my stock cats I actually cut the weld at the front. there is actually some straight pipe inside the stock cat that will allow you to use the reducer.
After all of the clamping and fighting I did, I wish I had just taken it to a muffler shop and let them stretch the 2 1/2 to make it 3" and then weld it together. I am very anal about exhaust leaks.
Good luck

 

[jdoc7]

Inferno,

I have the Roe cats 2.5 inlet and 3 outlet. There is no way you are gonna be able to clamp it tight at the inlet. The bend from the headers is too close to the connection making clamping nearly impossible. I welded mine. It can be done on the car when put on a rack.

 

[Jack B]

In short, pull the sills at home, take it to the muffler shop and have them assess what has to be done. Make sure you remove the sills before you go, don't let them remove them.

 

[Camfab]

If you haven't bought them, save yourself the hassle and buy the right part to begin with. Your going to end up with a Mickey Mouse job by some muffler shop who's going to charge you more than if you bought the right part in the first place.

 

[Inferno]

If you haven't bought them, save yourself the hassle and buy the right part to begin with. Your going to end up with a Mickey Mouse job by some muffler shop who's going to charge you more than if you bought the right part in the first place.

After reading this thread, I am starting to fall into your train of thought.