# Quick question
**URL:** https://forums.speedlife.net/t/quick-question/122211
**Category:** SON240sx Automotive
**Created:** [March 1, 2009, 2:57pm UTC](https://forums.speedlife.net/t/quick-question/122211 "2009-03-01T14:57:04Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@future\_240](https://forums.speedlife.net/u/future_240)
#### Post date: [March 1, 2009, 2:57pm UTC](https://forums.speedlife.net/t/quick-question/122211/1 "2009-03-01T14:57:04Z")
just wondering are there cats that go from 2" inlet to 3" out? or test pipes if so where could i find one?
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### Author:  [@sidewayz240](https://forums.speedlife.net/u/sidewayz240)
#### Post date: [March 1, 2009, 3:02pm UTC](https://forums.speedlife.net/t/quick-question/122211/2 "2009-03-01T15:02:36Z")
Why? Just get a 3" high flow. Its fine going from a smaller diameter to larger.
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### Author:  [@future\_240](https://forums.speedlife.net/u/future_240)
#### Post date: [March 1, 2009, 3:04pm UTC](https://forums.speedlife.net/t/quick-question/122211/3 "2009-03-01T15:04:28Z")
so a 3" cat will bolt up to the stock downpipe on my ka24de?
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### Author:  [@weaves](https://forums.speedlife.net/u/weaves)
#### Post date: [March 1, 2009, 3:04pm UTC](https://forums.speedlife.net/t/quick-question/122211/4 "2009-03-01T15:04:42Z")
I haven’t seen anything like that, there may well be something, have you thought of just welding a 2" to 3" reducer on one side of a normal 3" in/outlet cat?
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### Author:  [@sidewayz240](https://forums.speedlife.net/u/sidewayz240)
#### Post date: [March 1, 2009, 3:05pm UTC](https://forums.speedlife.net/t/quick-question/122211/5 "2009-03-01T15:05:44Z")
> [@so ui tryed to be a nice guy tonight](https://forums.speedlife.net/t/so-ui-tryed-to-be-a-nice-guy-tonight/20554/10):
>
> so a 3" cat will bolt up to the stock downpipe on my ka24de?
Yessir
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### Author:  [@fastback240](https://forums.speedlife.net/u/fastback240)
#### Post date: [March 1, 2009, 3:13pm UTC](https://forums.speedlife.net/t/quick-question/122211/6 "2009-03-01T15:13:26Z")
3 inch may be a touch to big for NA i would go 2.5 at the most
my 2 cents.
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### Author:  [@future\_240](https://forums.speedlife.net/u/future_240)
#### Post date: [March 1, 2009, 3:14pm UTC](https://forums.speedlife.net/t/quick-question/122211/7 "2009-03-01T15:14:30Z")
3" is fine…car is going to be boosted within the next month or so ive got a good deal on an apexi exhaust so…
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### Author:  [@snowboard\_240sx](https://forums.speedlife.net/u/snowboard_240sx)
#### Post date: [March 1, 2009, 4:27pm UTC](https://forums.speedlife.net/t/quick-question/122211/8 "2009-03-01T16:27:05Z")
> [@tweeter upgrade question](https://forums.speedlife.net/t/tweeter-upgrade-question/20533/3):
>
> 3" is fine…car is going to be boosted within the next month or so ive got a good deal on an apexi exhaust so…
if u are going to be boosting it then dont put the exhaust on yet. Wait until u have the new manifold and downpipe on. then u can just get a 3 inch downpipe. problem solved.
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### Author:  [@danbikes](https://forums.speedlife.net/u/danbikes)
#### Post date: [March 2, 2009, 12:02pm UTC](https://forums.speedlife.net/t/quick-question/122211/9 "2009-03-02T12:02:45Z")
> [@ps3 omfg!](https://forums.speedlife.net/t/ps3-omfg/20230/147):
>
> if u are going to be boosting it then dont put the exhaust on yet. Wait until u have the new manifold and downpipe on. then u can just get a 3 inch downpipe. problem solved.
x2, plus it’s much easier to do it off the car, then having to srtuggle with it while its still all mounted and such.
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### Author:  [@Martino](https://forums.speedlife.net/u/Martino)
#### Post date: [March 2, 2009, 12:04pm UTC](https://forums.speedlife.net/t/quick-question/122211/10 "2009-03-02T12:04:27Z")
Its not that hard to put on an exhaust and cat under the car… 😕
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### Author:  [@snowboard\_240sx](https://forums.speedlife.net/u/snowboard_240sx)
#### Post date: [March 2, 2009, 9:18pm UTC](https://forums.speedlife.net/t/quick-question/122211/11 "2009-03-02T21:18:11Z")
> [@Hypothetically Speaking...](https://forums.speedlife.net/t/hypothetically-speaking/20567/17):
>
> Its not that hard to put on an exhaust and cat under the car… 😕
why do a job twice when you can just do it once when u boost the car?