Catted vs non cat downpipe

[re-rx7]

I'm at a crossroads on whether I should go with the catted or non catted dp. I've seen on multiple sites that the tq numbers are significantly lower but I haven't seen any diff in power. Now that being said I plan on upgrading the turbo in the very near future. At these levels I don't really see a catted dp holding me back. Just looking for some input. Also I was planning on going with the Cobb dp.

 

[Kip2MyLou]

I'll be going Cobb too, but only because I live in MD so I can't go the catless route. I see those performance numbers too and they aren't too far from one of another. At least the results I've seen.

 

[Hijinx]

If your state does not require emissions testing of some sort go non-catted. Honestly, it then becomes a preference thing... I believe this topic has been covered thoroughly.

 

[RAAMaudio]

I feel it is important for the air we breath so I run one but built my own DP with a 100 cell, 5" diameter metal core cat. I wrapped it really well to keep heat out of the engine bay and to keep heat in the cat to help it function, light off faster, etc and so far working great even after 2 hard core days of use at a race track, around 200 minutes of hauling butt. I have the SS modded turbo as well and pass many supposedly faster cars

If you are in an area with inspections here is the trick way to go.

Ported stock manifold

Modified stock turbo

Modified stock DP
Just cut out the worst areas and weld in bigger sections, mod the heat shield just a bit, nobody would notice the changes and a modded stock DP should flow really well.

I have been tempted to do the DP mod just to see the results and I do not have inspections, tests, etc where I live but I like exploring the limits of stock based parts.

 

[Chuckable]

I used to think that getting every last ounce of power was of the utmost importance. But with the small difference in output of catted versus non-catted downpipes, not to mention the legal issues, seems reasonable to get a catted downpipe.

 

[re-rx7]

If your state does not require emissions testing of some sort go non-catted. Honestly, it then becomes a preference thing... I believe this topic has been covered thoroughly.

Topic hasnt been touched on much actually.

I feel it is important for the air we breath so I run one but built my own DP with a 100 cell, 5" diameter metal core cat. I wrapped it really well to keep heat out of the engine bay and to keep heat in the cat to help it function, light off faster, etc and so far working great even after 2 hard core days of use at a race track, around 200 minutes of hauling butt. I have the SS modded turbo as well and pass many supposedly faster cars

If you are in an area with inspections here is the trick way to go.

Ported stock manifold

Modified stock turbo

Modified stock DP
Just cut out the worst areas and weld in bigger sections, mod the heat shield just a bit, nobody would notice the changes and a modded stock DP should flow really well.

I have been tempted to do the DP mod just to see the results and I do not have inspections, tests, etc where I live but I like exploring the limits of stock based parts.

Agree with pushing the limits. I blieve cobb uses a 200 count cat.

I used to think that getting every last ounce of power was of the utmost importance. But with the small difference in output of catted versus non-catted downpipes, not to mention the legal issues, seems reasonable to get a catted downpipe.

I dont have emmissions but if the power diff is neglible i may go catted. I plan on using a ATP turbo but Iam curious on how the cat will handle the extra load.

 

[RAAMaudio]

I agree, I have ran a cat on all my modded cars for many years, though it might be just a token of the overall impact of what we do to our air every little bit helps.

I had a very modded C6 Vette convertible and did not like the smell it made when coming to a stop, top down, wind behind us and the exhaust I bought was supposed to be catted. I cut out what looked like cats and they were just small resonators so I installed 3" metal core cats and it not only cleaned up the exhaust, it sounded better as well as seat of the pants I could not feel a power difference.

I knew a 100 cell, 5" cat might not get warm enough but my ST exhaust sure smells like it does though I am sure having a 2-3 deep layer of wrap helps and it is SS which holds the heat better.

 

[re-rx7]

I wonder how well the cobb DP works? Seems like tq is affected but not the HP so much? Also Ive been researching Exhaust alot lately. Bigger isnt always better according to the big exhaust producers. Velocity and heat retention are the two big factors.

 

[Kip2MyLou]

I'm only going cobb for both because I like the sound of the exhaust and the downpipe is the same price as the 2JR one and I don't know of any other quality downpipes.

 

[re-rx7]

I'm only going cobb for both because I like the sound of the exhaust and the downpipe is the same price as the 2JR one and I don't know of any other quality downpipes.

Iwill go Cobb for catted. Racepipe will be ATP.

 

[Kip2MyLou]

I forgot about them. That's a good choice too.

Cobb for me personally seems to be the best way, catted wise at least.

 

[re-rx7]

I forgot about them. That's a good choice too.

Cobb for me personally seems to be the best way, catted wise at least.

Def. I just dont want the catted pipe to be holding me back when i upgrade the turbo. The other gd thing about the cat though is that it may keep it civil as far as noise is concerned.

 

[Kip2MyLou]

Def. I just dont want the catted pipe to be holding me back when i upgrade the turbo. The other gd thing about the cat though is that it may keep it civil as far as noise is concerned.

And that's the other bug concern for me the noise. I don't want it loud but a good ramble and crack on wot.

 

[re-rx7]

And that's the other bug concern for me the noise. I don't want it loud but a good ramble and crack on wot.

I agree with all of this. As ive grown up i want the car to be tolerable.

 

[gojagz]

The topic has been touched on.. extensively. http://www.fiestastforum.com/forum/threads/1166-To-CAT-or-not-to-CAT-that-is-the-question

 

[re-rx7]

The topic has been touched on.. extensively. http://www.fiestastforum.com/forum/threads/1166-To-CAT-or-not-to-CAT-that-is-the-question

the lack of knowqledge from 2j racing in that post literally gave me ebola...

 

[Benito Malito]

It is irresponsible and unethical to run catless on a street car. Doesn't matter where you are.

 

[re-rx7]

Im in Texas and not long ago I wouldhave said your stupid. I now prefer a cat.

 

[JPGC]

It is irresponsible and unethical to run catless on a street car. Doesn't matter where you are.

So says the angel here...roll eyes. Can't say that though since your a Giants fan iaw your profile, lol. I only say this because I run a catless downpipe and calling me irresponsible and unethical is a judgement that you or anyone else does not have the right to pass unless you are perfect in every way.

 

[BoostBumps]

Yeah...admittedly I've done a few catless downpipes over the years which I've since learned really didn't buy me much more as far as added performance over installing a DP with a highflow cat...Also I found that catless DP's tend to result in louder exhausts and stink like hell...I guess at this point in my life I'm getting too old (or finally maturing) to tolerate both the added exhaust noise and fumes and hell maybe even finally becoming more environmentally conscious...But no judgement....to each their own...