question for you exhaust guys

[kzink]

well i am in need of a new catalytic converter for my smog check coming up here in a few months and if you live in ca you know how much of a pia it can be. well i need a cat and while im down there im going to build a custom cat back exhaust using 2.5 in piping would this cat flow sufficient enough or flow to much for the 3vze cant be worse then my gutted cat right? or would running flanged 2.5in piping from the first flange to a complete 2.5in system be bad? MagnaFlow 38016 - MagnaFlow California 30000 Catalytic Converters - Overview - SummitRacing.com

 

[csrobb007]

Read this before you spend a bunch of money...

Clearing Up the Myth About High Flow Catalytic Converters

Just my 3.0 cents worth

 

[Hyde802]

Just my 3.0 cents worth

That made me lol.

I have a highflow cat (no name brand) and a flowmaster 40 on my 92. Sounds great, didnt notice any performance gains. If your going to do anything to the exhaust performance wise, look into a set of headers.

 

[kzink]

im not looking for performance gains im looking to pass smog, and i have an extra 2.5 in/out turbo muffler at the house so i was going to use that. i just wanted to make sure it wouldnt be to big or what not, stock is what 2.125 or 2.25? so i was going going to run stock to the flange after the o2 then 2.5 all the way back? only reason for replacing my stock muffler and exhaust is that the exhaust and muffler are starting to rust away

 

[csrobb007]

I did similar with mine...cut both tubes before the "y", made my own y-tube (fishmouth), 2.5 from there back with a Flowmaster and put both O2's before the muffler...no power gains to speak of, but picked up a little mileage...probably traded a little torque (not that there's really any to speak of) on the bottom range for the mileage, but that's OK...I have other stuff to drive when I want to spin tires
Sounds OK I guess (it's not a V-8)...it is what it is.

 

[mpleitez]

y-pipe design

I did similar with mine...cut both tubes before the "y", made my own y-tube (fishmouth), 2.5 from there back with a Flowmaster and put both O2's before the muffler...no power gains to speak of, but picked up a little mileage...probably traded a little torque (not that there's really any to speak of) on the bottom range for the mileage, but that's OK...I have other stuff to drive when I want to spin tires
Sounds OK I guess (it's not a V-8)...it is what it is.

Did you have any pictures of the y pipe? I'm looking to get mine redesigned and would like to see your design if possible?

 

[mpleitez]

y-pipe design

I did similar with mine...cut both tubes before the "y", made my own y-tube (fishmouth), 2.5 from there back with a Flowmaster and put both O2's before the muffler...no power gains to speak of, but picked up a little mileage...probably traded a little torque (not that there's really any to speak of) on the bottom range for the mileage, but that's OK...I have other stuff to drive when I want to spin tires
Sounds OK I guess (it's not a V-8)...it is what it is.

Did you have any pictures of the y pipe? I'm looking to get mine redesigned and would like to see your design if possible?

 

[csrobb007]

When I'm back home next week...I'll PM you with pics

 

[mpleitez]

thanks

When I'm back home next week...I'll PM you with pics

I appreciate it thanks!