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Sourskittle

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I'm not convinced an aftermarket dp with a cat will really do any better than a catted stock one....
 


Kip2MyLou

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The stock DP provides the same power results as a catted aftermarket DP, like Cobb? I always thought the reason of getting the DPs were to get more power. Ha.

I'm just asking because I was planning on getting a catted DP from Cobb, to go stage 3.
 


Young L

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The stock DP provides the same power results as a catted aftermarket DP, like Cobb? I always thought the reason of getting the DPs were to get more power. Ha.

I'm just asking because I was planning on getting a catted DP from Cobb, to go stage 3.

I havent seen anything saying one doesnt which is why im confused also.
 


MOFiST

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I'll say my butt dyno tells me otherwise on my 2jr catted pipe with my tune which was the identical before and after. I could feel an increase in power however without a way to log. It's not dyno certified ;)
I did notice the stock dp necks down pre cat whereas the 2jr is full 3" pre cat.
 


DHM1

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I'll say my butt dyno tells me otherwise on my 2jr catted pipe with my tune which was the identical before and after. I could feel an increase in power however without a way to log. It's not dyno certified ;)
I did notice the stock dp necks down pre cat whereas the 2jr is full 3" pre cat.
Okay. Haha. Maybe somebody can chime in on this. I know catless shows more gains but I know the catted ones still show a pretty good increase themselves.
I havent seen anything saying one doesnt which is why im confused also.
Yes a catted 3" down pipe will make more power than the OEM one. Larger pipe less restriction and most use a "spun" core cat which are your typical high flow cats. How ever there has not been a cheaper high flow cat that I have not seen clog, fall apart, or cause power losses over time 10k-15k miles. A cat relies on being a certain temp to work properly most of the high flow cats never reach that temp to keep them from building up soot, oil deposits, or carbon. So spend an extra $200 on a converter for something that makes less power and will not last as long just not worth it when you way the options. Now if you have to have it for legal reason then of course its not worth the fines. As for the smell someone said about if the down pipe or exhaust does not seal and leaks yup you will smell some hydrocrabons and other things that you may not like but quality products should not leak and keep the exhaust behind the car!

Russ
 


MOFiST

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Yes a catted 3" down pipe will make more power than the OEM one. Larger pipe less restriction and most use a "spun" core cat which are your typical high flow cats. How ever there has not been a cheaper high flow cat that I have not seen clog, fall apart, or cause power losses over time 10k-15k miles. A cat relies on being a certain temp to work properly most of the high flow cats never reach that temp to keep them from building up soot, oil deposits, or carbon. So spend an extra $200 on a converter for something that makes less power and will not last as long just not worth it when you way the options. Now if you have to have it for legal reason then of course its not worth the fines. As for the smell someone said about if the down pipe or exhaust does not seal and leaks yup you will smell some hydrocrabons and other things that you may not like but quality products should not leak and keep the exhaust behind the car!

Russ
I'm sure you've seen more than most of us. Will my exhaust wrap help get that cat hot enough? I bet carbon is going to be an issue over time. It actually was going through my mind about gutting my cat. In a year or so I might inspect it and if need be perform the screw driver mod. Another option I think [MENTION=636]RAAMaudio[/MENTION] mentioned would be reusing the OEM cat in aftermarket downpipe.
 


DHM1

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I'm sure you've seen more than most of us. Will my exhaust wrap help get that cat hot enough? I bet carbon is going to be an issue over time. It actually was going through my mind about gutting my cat. In a year or so I might inspect it and if need be perform the screw driver mod. Another option I think [MENTION=636]RAAMaudio[/MENTION] mentioned would be reusing the OEM cat in aftermarket downpipe.
Exhaust wrap will help but with the lower grad materials that most downpipes on the market are made out of wrap will just cause corrosion. Cutting the stock cat and using it would be bad for packaging, much lower flow, and any one that had worked in OEM prototyping would know cutting metal near a cat is no good. Metal dust and slivers can clog holes in a cat and you can not just blow them out.

Russ
 


RAAMaudio

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My idea was on the stock DP to just cut out the restrictive areas and weld in sections to free up the flow. It was not something I have ever done, it was it was based on an idea to help those that wanted to stay as stock looking as possible for whatever reason yet help the DP flow better.

I considered doing it just to test it out to see what happened but instead just stuck with a big DP.

I did not consider the metal particles getting stuck in it and starting to clog it up, make sense, one would have to use a different method to cut it open.

I have used quite a few aftermarket high flow cats but none for longer than 5k miles or so thus did not know they usually start to fail at 10-15k miles.

------------

Russ,

If header wrap will cause corrosion on lessor grade materials it might be better to use a metal stand off heat shield to protect things near it instead of wrapping it, which I always done except once, on this car.

I use 305 or 409 SS when I build such parts, depends on what I can find, I use the best when available.

Would you consider them good enough to wrap if one wanted to do so?
 




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