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Discussion Starter #1
What's your choice of catalytic converter size with your turbo DD? What HP and PSI are you running?

I'm running a D16Y7 block and head with no-tec. Pushing 22psi through this well built and durable bottom end with a stock 98 Si cat. Runs pretty good but with the test pipe replacing the cat, it gets up to 26-27psi boost. This is fine because it's tuned all the way up there. The waste gate doesn't open, so the turbo is providing all it can.

Recently replaced the stock Si cat with a Magnaflo 3" 48 state legal catalytic converter. I've gained 1psi to achieve 23psi boost while still being street legal in Ontario Canada.

Don't know my HP but it spins the tires in 1st, 2nd at will and chirps them in 3rd.
 

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I was wondering this myself! Did that magnaflo converter have a honeycomb on the inside and what did it cost?
 

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Discussion Starter #4
I was wondering this myself! Did that magnaflo converter have a honeycomb on the inside and what did it cost?
Yes it has the honeycomb inside. It is 48 state legal OBDII cat. It costs about $120 on eBay. Had to weld my own flanges on, which is cool with me.
 

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()*#$(*$
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3", spun metallic core, or really, nearly any 3" cat. I've used Carsound which I think was bought out by Magnaflow, cheaper eBay stuff and whatever I could get through parts stores. Overall, the Magnaflow is about the best you are going to get without paying a heck of a lot of money.

The metal matrix cats are really good, flow very well and actually do what a cat is supposed to do pretty well, too, but are not cheap for something that will hold up. These will take the most abuse from heat, though.


Any aftermarket cat will cannot and will not last as long as an OBDII devil worshipping cat, and those won't last as long as most OEM cats.
 

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My advice is don't run one unless smog regulations are hard on u like in California where they have surprise smog stops
 

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Forgive me if I'm wrong since WI laws are nearly non-existent, but I though running an OBD2 car with an OBD1 ecu makes it non-compliant in any municipality that tests emissions. What's the point of having a cat converter if the rest of the car won't pass? If the cops are looking under the car, a hollowed out stock cat welded around a test pipe would work just the same.
 

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the artist formerly known as drexelstudent11
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Forgive me if I'm wrong since WI laws are nearly non-existent, but I though running an OBD2 car with an OBD1 ecu makes it non-compliant in any municipality that tests emissions. What's the point of having a cat converter if the rest of the car won't pass? If the cops are looking under the car, a hollowed out stock cat welded around a test pipe would work just the same.

lower the car so much they can't look :lol::bigok:
 

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I have run a three inch magnaflow, then went to a 2.5 jdm gsr cat purchased from hmotors. I was hoping to quiet down my 3 inch exhaust and it did just a tad. any way I say for the street go with 2.5 or 3 inch and you should still have decent power, your turbo will just spool a little later.

I used to run no cat and did not care for the extra smoke a unburnt fuel smell, that comes with a boosted honda.

I even recirculate my crankcase back in to my intake(edelbrock turbo kit) I enjoy that my car burns some what clean. So for me its worth it to run a cat, if I nee more hp I can just run more boost.
 

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Discussion Starter #13
Forgive me if I'm wrong since WI laws are nearly non-existent, but I though running an OBD2 car with an OBD1 ecu makes it non-compliant in any municipality that tests emissions. What's the point of having a cat converter if the rest of the car won't pass? If the cops are looking under the car, a hollowed out stock cat welded around a test pipe would work just the same.
The law in Ontario Canada states that any OBDII '98 and newer get the plug in test. Anything older than '98 gets the sniffer up the tail pipe test. I own a 96 converted to OBDI, which passed last time testing, with OEM Si cat. Spot checks don't happen very often, just near those classic car shows for easy pickin's.

What sucks is 60mi north in the same province, doesn't have e-testing.
 

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Not running a cat on a street-driven car is just discourteous. It stinks. A high-flow cat takes care of nearly all the stench and doesn't cost you much at all both monetarily or power wise.
Ive smelt nastiness from plenty of catted cars.

Mine being one of them, its annoying, but i think its fading away.
 

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Whats a catalytic converter?
Same thought ran through my head....

Anywho, I would recommend an OEM diesel cat. They are "huge" and are built with extreme temp duties in mind. They might not clean the exhaust fumes as well, but they would last. Will it pass emissions testing? IDK, but it at least would look the part on the side of the road.

Not running a cat on a street-driven car is just discourteous. It stinks. A high-flow cat takes care of nearly all the stench and doesn't cost you much at all both monetarily or power wise.
Yeah, no. A well tuned 4 cylinder car will not smell any worse then any other stock V8 powered car on the road. Hell even some V6s smell worse. Some of which I work with on a daily. Just my opinion on your statement. :sweatdrop:
 

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The One I posted passes emissions with flying colors...

And is cheaper, better design, smaller package, best flow...


:/


A well tuned car without a cat and a full sealed exhaust does not smell any different than any other gas operated engine.

While most of the time, a cat will make the exhaust smell less gas-like. When heat-soaked, they smell very sulfer-esque.
 

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I wouldn't get a Catalytic converter to make your car quieter, especially if it was a cat marketed for high flow.

Cat's don't flow because they are baffled, not because they absorb sound.

Get a resonator or a Magnflow muffler, Flowmasters SUCK.

Or a vibrant resonator, or a cherry bomb if you want it to sound more old school.

Buy all your shit off eBay 2 weeks ahead of when you need it, then you can spend the money you saved by thinking ahead on labor to get it installed.


Mufflers muffle, Catalytic converters are simply a surface in the exhaust that turns really reactive gasses into less reactive gasses.


BTW, you can almost pass a tune with lean mixtures and tuning for it.

If you know how to tune.

Being on a site devoted to Tuner Cars I would hope for more people tuning.
 
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