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Are there Down Pipes with a Cat and 3" Outlet?


svx6

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So I did a search here and it seems like all of the downpipes taper back down to 2.5 inches to mate to the stock exhaust system. Are there any around that have a 3" outlet...I was thinking about going 3" piping custom piping from turbo to the tailpipes. Would I be better off just getting one of the downs that has a 2.5" outlet and having it cut, and then having a 2.5" adapter handy if I ever decided to go back to stock exhaust system? Gets confusing after a while...

 

thanks in advance,

Syd

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The non-existent and never to be produced Helix downpipe was to have such specs. Because it was rumored to have such a great price I was waiting for it. I will probably go with the Autospeed downpipe, as it does exist and is at least reasonable in price. Lachute describes having both a 2.5 inch and 3 inch flange, but I cannot find on their website the actual pipe dimensions, also a little pricey, even factoring a Canadian conversion. Perrin does have a catless 3" FTW or FTL, depending on your point of view. I'm not sure about the AVO specs, but if you've got the money . . .

 

Just trying to boost my post count. I believe I'm the most senior "new member" by a longshot.

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PDE has a full 3" outlet, with a 2.5" reducer welded in to mate with the stock catback. You can remove this reducer and you will have a full 3" flat flange to connect to real full length 3" catbacks.

 

Actually, mine will be for sale shortly as it wont work with the direction I will be going with the car in the near future ;).

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Most of the WRX units are 3". APS makes a 3" or 3.5" with optional HFC insert. If you going custom catback, then any WRX/STi DP should work fine. I'm using my old Turbo XS 4"DP (3" outlet) with a turbo XS 3" HFC and 3" custom piping to the tailpipes (http://legacygt.com/forums/intake-exhaust/40436-my-stealth-dual-exhaust.html). Works fine! I kept the stock system so I can change back at any time.
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Here is an explanation from PDE. Not that I agree or understand...

 

I think it means that you need some kind of expansion joint here and that a custom joint isn't worth the HP gains.

 

PDE :: CREATIVITY | PERFORMANCE | VALUE

 

You dont need any thing fancy. Basically the pipe is 3" all of the way, and at the flange, it has a reducer welded in with a spot for the donut gasket to sit. When you want to use it with a full 3" catback, just cut the reducer out.

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The non-existent and never to be produced Helix downpipe was to have such specs. Because it was rumored to have such a great price I was waiting for it. I will probably go with the Autospeed downpipe, as it does exist and is at least reasonable in price. Lachute describes having both a 2.5 inch and 3 inch flange, but I cannot find on their website the actual pipe dimensions, also a little pricey, even factoring a Canadian conversion. Perrin does have a catless 3" FTW or FTL, depending on your point of view. I'm not sure about the AVO specs, but if you've got the money . . .

 

I think the AVO has a 3" tubing the whole way with a 2.5" opening (don't think there's a slip fit). However given the price and the cat location you're probably better off elsewhere. If I have problems in 5 years with CA emissions I'll consider it.

 

I think the Lachute pieces are made to order.

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