Ditching catalytic?
#1
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Ditching catalytic?
I got an enthuza 2.5" catback and im not reaching for big power just yet, 200hp initially.
Garrett T25 of an SR20, if it matters. So not the most efficient thing up top.
What are the pros and cons of ditching the cat? Worth the effort and supposedly the smell?
Garrett T25 of an SR20, if it matters. So not the most efficient thing up top.
What are the pros and cons of ditching the cat? Worth the effort and supposedly the smell?
#3
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I've heard its a lot more than that on a turbo car.
And a miata is not going to **** the environment.
I have no smell...other than the unburnt fuel smell of running god awful rich...cons is obviously illegal.
And a miata is not going to **** the environment.
I have no smell...other than the unburnt fuel smell of running god awful rich...cons is obviously illegal.
#5
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I'm not concerned to much about illegal because I can just build a o2 simulator so I can pass emissions, and no one does visual inspection in NY.
I just have the chance to ditch my cat because someone can build me a test pipe as long as i can provide flanges and tubing.
So I am just curious how much advantage people are seeing when ditching the cat.
Naturally I would rather keep the cat for the car to be more environmentally friendly and its one less thing for me to wire into the car.
I just have the chance to ditch my cat because someone can build me a test pipe as long as i can provide flanges and tubing.
So I am just curious how much advantage people are seeing when ditching the cat.
Naturally I would rather keep the cat for the car to be more environmentally friendly and its one less thing for me to wire into the car.
#6
I've had the cat off my car since I went turbo years ago. I have no complaints about the smell, buses are usually the only vehicles that the smell aggravates me.
Having a miata is already being "environment friendly". You could be driving a suburban or expedition around. Bump your karma and plant a tree once you take the cat off.
I had a guy give me the visual check for my cat. He said just swap in you cat, show it to me, then do whatever you want afterward. Whenever I need to again I still have the cat to throw on for the 30 mins or so to pass my test.
Vash-
Having a miata is already being "environment friendly". You could be driving a suburban or expedition around. Bump your karma and plant a tree once you take the cat off.
I had a guy give me the visual check for my cat. He said just swap in you cat, show it to me, then do whatever you want afterward. Whenever I need to again I still have the cat to throw on for the 30 mins or so to pass my test.
Vash-
#10
How about the fact that you're not in competitive racing and that last 1 or 2 hp isn't necessary, and that you're miata is going to be plenty fast even with the cat if it's turbocharged (get a high flow cat maybe?). Add to that the fact that you'll probably be running mostly either rich or lean of stoichiometric and I'd imagine the car is not going to be as eco-friendly as it used to be......Now everyone can commence bashing me on this opinion.
#11
lol
I definitely didn't do it for any other reason than my turbo **** came with a test pipe. So when I put everything in, that was part of it.
But now ordering the new 3" Enthuza exhaust, I also am having Jason make me a 3" test pipe as well. I guess I feel like I never really had the cat, no need to add one now.
ANYWAYS!!!! Cats are the hot item on the market now. Have one on your car? Not till the thieves get to you!
Vash-
I definitely didn't do it for any other reason than my turbo **** came with a test pipe. So when I put everything in, that was part of it.
But now ordering the new 3" Enthuza exhaust, I also am having Jason make me a 3" test pipe as well. I guess I feel like I never really had the cat, no need to add one now.
ANYWAYS!!!! Cats are the hot item on the market now. Have one on your car? Not till the thieves get to you!
Vash-
#12
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just wondering.... what boost are you running with the T25? ... there may be easier ways to make more power. Also, keep in mind that the S14 T28 can be found for about 300-500 and is single ball bearing, much more efficient and slightly bigger.
#14
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I would imagine that it could be a bottle neck there, but having a freeier flowing exhaust after the cat would allow it to breath easier as well.
I'm not an exhaust expert, just a guess.
As for upgrading the turbo, no point because I already have the T25 and if i'm gonna be buying a new turbo ill probably splurge on a GT2560.
I'm just curious if anyones done any before and after comparisons, or how many are running a stock cat.
#15
Your miata will pollute a couple of hundred times more than your average SUV without a cat. If you want extra power AND good karma, go metallic core cat.
Edit 2: Seems like a good cat takes away between 80-97% of NOx, with the higher percentage reserved for large marine diesel engines. Will see if i can find an article in english to share.
Edit 3: I give up the search for hard facts. EPA and such agencys state in a lot of articles that the effectiveness is 80%<, but they never publishes any measured values.
Edit 2: Seems like a good cat takes away between 80-97% of NOx, with the higher percentage reserved for large marine diesel engines. Will see if i can find an article in english to share.
Edit 3: I give up the search for hard facts. EPA and such agencys state in a lot of articles that the effectiveness is 80%<, but they never publishes any measured values.
Last edited by Sentic; 05-04-2008 at 06:08 PM.
#16
i went no cat for $$$ reasons...
my cat was clogged and i didnt want to buy a new so i made a test pipe for $6 and learned how to weld at the same time. Dont have too bad of a smell at all to me i dont mind the smell of unburnt gas when i get out of the car because i dont hangout behind the muffler and the sound is def on the loud side for a N/A car...
to each his own
my cat was clogged and i didnt want to buy a new so i made a test pipe for $6 and learned how to weld at the same time. Dont have too bad of a smell at all to me i dont mind the smell of unburnt gas when i get out of the car because i dont hangout behind the muffler and the sound is def on the loud side for a N/A car...
to each his own
#19
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Why run a 2.5" DP, 2.5" exhaust, and then choke the **** out of it with a 2.25" cat? If you're going to run a cat, run a 2.5" high-flow or larger. I'm using a 3" high-flow to match my 3" DP and 3" catback.
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