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Downpipes

So I am thinking of purchasing an apexi n1 downpipe because they claim it widens up so early it gives good turbo horsepower gains. But is there really a noticeable difference? can I just get some meghan racing one or does some have a used one?
 

IncorpoRatedX

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May 28, 2003
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Arizona
i ran a megan 2g no cat downpipe on a 20g with a megan internal dump o2 housing, engine had 8.5:1 and 280 cams, i had zero complaints about the fitment or flow.

you're trying to measure something so tiny that you'd barely notice a difference in power curve
 

jepherz

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Aug 8, 2004
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KC, Missouri
When you replace your entire exhaust, and then work on intake improvements, you'll start to feel a difference.
 

speedyvr4

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Jan 1, 2006
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1,245
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miami, fl
I have a megan on my 1g for 3 years now and it works great. I have agarage custom one on the gvr4( till curve then 2/12" till cat)stock bend. the megan feels better on the butt dyno bet the dsm is lighter too. as far as the difference before and after, I was happy with both results. I think its a well worth mod for the money.
 
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mitsuturbo

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Jun 2, 2008
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Near Seattle, Washington
As far as exhaust goes, the one thing that REALLY woke my car up more than any other was deleting the cat. I think apexi and megan downpipes are pretty comparable, from what i've seen/experienced.
 
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Specter

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Apr 20, 2008
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Karachi, Pakistan
What a coincidence, i was just wondering about the down pipe while logging in at the forum and saw this topic. I was wondering whats the diameter of the stock down pipe and to how much do you guys usually increase it to? Noticeable difference?
 

jepherz

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Aug 8, 2004
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KC, Missouri
I think stock is maybe 1-7/8" ? Most people with stock style turbos (14b, 16g) go with 2.5" DP off the factory O2 housing.
 

So could I get a down pipe that is flanged 2.5" at one end and 3" at another because I have the off road pipe thats 3" but im not sure how to get it all connected up to my turbo.
 

bustedsm

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Nov 30, 2006
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844
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Ripley, Tennessee
Yes, they have downpipes that expand from 2.5" from the o2 housing to 3" at the cat-back....
 

BluFalcon

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Jan 20, 2002
Messages
1,312
Location
Wichita, KS
Road Race Engineering sells a downpipe for the guys running an EVO3 O2 housing. It comes off the outlet at 2.5 in then flares out to 3 in after the flex section. I'm using the 1G version of their DP in my GVR4 with a modified Megan racing 1G AWD catback exhaust.
 

mitsuturbo

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Jun 2, 2008
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Near Seattle, Washington
Quoting MeanGreenVR4:
So I am thinking of purchasing an apexi n1 downpipe because they claim it widens up so early it gives good turbo horsepower gains. But is there really a noticeable difference? can I just get some meghan racing one or does some have a used one?



IDK how much it will help if you're still running a stock catback.
 

Specter

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Apr 20, 2008
Messages
367
Location
Karachi, Pakistan
Quoting mitsuturbo:
Yes.
ESPECIALLY If it's a cat eliminator downpipe.



I just got my 2.5" down piping done. I must say its hell of an improvement. Probably the best work i have done on my car so far.
 
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