Cat restriction

[my dreamt dsm]

Getting my hks hiper in a week and maybe my punishment o2 housing. My question is with my stock cat will it effect my exhaust flow since the two will be high flowing and then they hit the restriction of the cat.
If you read the venturi effect it states that when high pressure comes into a narrow path it will exit out faster. Similar to watering the grass with your thumb over the hose and the water exiting out will flow further.
Now I live in cali and I don't want to be fine with a $1000 bill and impound with out a cat.

 

[9!'clipseDOHC]

Getting my hks hiper in a week and maybe my punishment o2 housing. My question is with my stock cat will it effect my exhaust flow since the two will be high flowing and then they hit the restriction of the cat.
If you read the venturi effect it states that when high pressure comes into a narrow path it will exit out faster. Similar to watering the grass with your thumb over the hose and the water exiting out will flow further.
Now I live in cali and I don't want to be fine with a $1000 bill and impound with out a cat.

Yes a cat will effect your flow/performance a little bit but since you are worried about fines and inspections then keep it. It won't help your performance enough to make it worth getting in trouble with the law in my opinion.

 

[yukiz]

taking of Cat is breaking federal law...... you might get fine about $2500, car might be impounded it is not worth it to pickup 5-10 extra HP. if you want, you might want to start looking at Exhaust cutout..... just to play safe.....

 

[my dreamt dsm]

Thanks guys I was worried about that and yes. I think the con's out weigh the pro's on this one. I might have to keep it after all.
I think with the combination of the exhaust and o2 should already gain some amount of hp even though the cat is in the way.
Post marked as helpful.

 

[mike96]

you could always replace the cat with a good high flowing aftermarket one. Magnaflow makes a 3" CARB legal one wont be nearly as restrictive as a stock.

 

[SOADweskey]

I also say get a good 3" high flowing one. I made over 440 awhp with a magnaflow high flow on my car. I don't know how much the stock one would limit it but man is it small.

 

[my dreamt dsm]

Thanks guys! I'll look into that. My car is to low for them to look under any ways. Cops don't mess with dsm here much. They mostly target honda's because of stolen parts.

 

[2GbTalonGuy]

It would be a pretty big PITA to have to remove the test pipe and replace the cat just to go through emissions testing, and then go back and swap them back out after testing. I also vote for 3" hi flow cat.

 

[UofACATS]

It would be a pretty big PITA to have to remove the test pipe and replace the cat just to go through emissions testing, and then go back and swap them back out after testing. I also vote for 3" hi flow cat.

Actually it goes like this: One day out of the year I put the jack under the rear of the car, slide under on my creeper, loosen two clamps (4 bolts which are antiseized) remove test-pipe, fit the cat (they're the same size pipe), tighten the clamps, slide back out, lower car.

Pass emissions, and reverse procedure. Easy.

 

[razrman8]

I am currently running no cat. Had problems with my t-25 boosting only to 7-psi and my 16g boosting to 2-psi. After a week of diagnosis, turned out to be a clogged cat restricting the flow, not allowing to spool. Though I am running a test pipe, helps to know the right people when inspection time comes.

 

[907gs-t]

Just replace it with a high flow cat & call it a day.

 

[MJBean420]

^+1! I got a high flow cat. seems to make a difference...