Downpipe questions

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slipknot51
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Downpipe questions

Post by slipknot51 »

So i am currently talking to my friend and he got a 3 inch downpipe back exhaust system out of a 2009 Subaru Impreza wrx sti hatchback and i was looking at taking the downpipe off his hands but first i want to see if any one might know if it would work for our First gen's or if there is any modifications that would be needed to be done to make it work
92 T- leg Tdo4/top mount,3" inch exhaust ,5 speed 2.5 rs trans, sti seats Wrx rear seats kartboy short throw shifter,Kyb gr2 struts
08 Spec b Legacy
euroshark
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Re: Downpipe questions

Post by euroshark »

i dont believe it will. the length of it will not line up with the exhaust. the top and bottom flanges are different as well.
http://r-hgarage.com/ -CLICK ME
92 legacy ss 5spd white- track car
03 wrx wagon 5spd silver- DD
84 chevy k20 4spd 4x4 blue lifted on 35"- wheeler/heavy hauler
Falken-18c
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Re: Downpipe questions

Post by Falken-18c »

cut and weld
slipknot51
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Re: Downpipe questions

Post by slipknot51 »

Yeah i remember reading that from the other post but i wasn't sure about the 2009 downpipe. I'm wondering when you were talking about the flanges being different there euroshark. how much different are we talking would they still work mate up to the typical subaru exhaust housing that they use on the turbo's. Plus i was thinking of hooking it up to my custom stock exhaust which i know is 2.25 inch im hoping that the 3/4 of a inch difference would not create to much of a bottle neck in the system other wise going out to get me some 3 inch pipe
92 T- leg Tdo4/top mount,3" inch exhaust ,5 speed 2.5 rs trans, sti seats Wrx rear seats kartboy short throw shifter,Kyb gr2 struts
08 Spec b Legacy
euroshark
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Re: Downpipe questions

Post by euroshark »

the bottom flange will have to be rotated. the top flange might not be an issue but i heard it was for my 07 legacy. 3/4in difference will kill the flow pretty bad. 1/4in or less is ok.
http://r-hgarage.com/ -CLICK ME
92 legacy ss 5spd white- track car
03 wrx wagon 5spd silver- DD
84 chevy k20 4spd 4x4 blue lifted on 35"- wheeler/heavy hauler
slipknot51
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Re: Downpipe questions

Post by slipknot51 »

Yeah i could always just run a 90 degree out the with some 3 inch pipe and run the exhaust out by the passanger's door lol jk i know that my friend that has a 4 inch bell mount dp has his hooked up into a 3 inch dp back exhaust and is having no issue at all
92 T- leg Tdo4/top mount,3" inch exhaust ,5 speed 2.5 rs trans, sti seats Wrx rear seats kartboy short throw shifter,Kyb gr2 struts
08 Spec b Legacy
euroshark
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Re: Downpipe questions

Post by euroshark »

i had a 4" catless bellmouth dp on my last sti, shit was badass and loud as hell
http://r-hgarage.com/ -CLICK ME
92 legacy ss 5spd white- track car
03 wrx wagon 5spd silver- DD
84 chevy k20 4spd 4x4 blue lifted on 35"- wheeler/heavy hauler
Apex3
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Re: Downpipe questions

Post by Apex3 »

slipknot51 wrote:Yeah i could always just run a 90 degree out the with some 3 inch pipe and run the exhaust out by the passanger's door lol jk i know that my friend that has a 4 inch bell mount dp has his hooked up into a 3 inch dp back exhaust and is having no issue at all
Yea mine is 4" to 3" to 2.25" to 2.5" :lol:

It'll bottleneck but it'll still flow better than before, just not getting the full potential of it.
slipknot51
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Re: Downpipe questions

Post by slipknot51 »

Yeah i was thinking that it might give the car a little more a rumble noise thats what im hoping for at least plus im gettng a well know down pipe for cheap so i cant complain. If i need to do a little cutting and welding then im fine
92 T- leg Tdo4/top mount,3" inch exhaust ,5 speed 2.5 rs trans, sti seats Wrx rear seats kartboy short throw shifter,Kyb gr2 struts
08 Spec b Legacy
Apex3
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Re: Downpipe questions

Post by Apex3 »

I love the way my car sounds after the DP, really made a difference, and just in the sound itself, it didn't get any louder which is a plus to me.
slipknot51
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Re: Downpipe questions

Post by slipknot51 »

yeah thats good to hear i was thinking of tying a few thing and seeing what setup i would like to go with i have a wrx downpipe back exhaust that i got for 20 buck that i cut the resonator out of and lengthen to fix my legacy and i was going to see what it sounded like with the new down pipe and maybe my modified exhaust section to see what she really sounds like
92 T- leg Tdo4/top mount,3" inch exhaust ,5 speed 2.5 rs trans, sti seats Wrx rear seats kartboy short throw shifter,Kyb gr2 struts
08 Spec b Legacy
slipknot51
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Posts: 181
Joined: Wed Apr 28, 2010 4:02 am
Location: Minneapolis,MN

Re: Downpipe questions

Post by slipknot51 »

So i got the downpipe from my friend turns out for 100 Buck i got an awesome Invidia catless 3 inch divorced downpipe that MSRP i think is 300 steal but the down fall is that it look like it's about 6 inches to long but the flanges and every thing line up awesome. Well me personally dont trust myself to do the cutting and welding but im glad i have coworkers that do that stuff all the time so the end result will look nice plus the O2 bung add in at the the bell mount maybe 2 in case i get myself a wideband for the future
92 T- leg Tdo4/top mount,3" inch exhaust ,5 speed 2.5 rs trans, sti seats Wrx rear seats kartboy short throw shifter,Kyb gr2 struts
08 Spec b Legacy
ciper
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Re: Downpipe questions

Post by ciper »

I dont think reducing the size after the downpipe is as much of a restriction as you'd think. By then the exhaust gasses have lost a significant amount of heat so the velocity is much lower.
slipknot51
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Location: Minneapolis,MN

Re: Downpipe questions

Post by slipknot51 »

Yeah it seem to be working quite well actually. I havent notice any lack of power and im sure i gained some i got the sound i wanted out of the remaining stock exhaust and the shorting the downpipe fits awesome i ended up cutting and welding every thing and adding the o2 bung runnning with my mbc about 11.5 just before fuel cut and the car runs and sounds awesome with the swap
92 T- leg Tdo4/top mount,3" inch exhaust ,5 speed 2.5 rs trans, sti seats Wrx rear seats kartboy short throw shifter,Kyb gr2 struts
08 Spec b Legacy
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