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UpPipe questions...

5K views 21 replies 12 participants last post by  Strider327 
#1 ·
I have got a few questions concerning UpPipes...
-Does the diameter of the UpPipe really matter?
-Does the quality of UpPipe matter? Like would it matter if i bought this cheesy EBAY one eBay Motors: UP PIPE UPPIPE FLEX 02-05 03 04 SUBARU IMPREZA WRX STI (item 300193158943 end time Jan-29-08 20:58:03 PST)
or would one like this be better eBay Motors: Invidia Stainless Up Pipe Subaru WRX / STi 2002+ Uppipe (item 370016292982 end time Feb-01-08 17:10:30 PST)
-And finally, should i get one with a flex joint or not? Does it affect performance with one?
Thanks...
 
#4 ·
Well actaully i bought the invidia one and it does work great. The flex is in order to PREVENT leaking at the flanges and make installation a little easier. They dont make 3 inch up pipes, only up pipes that match the diameter of your manifold. However the good ones have a taper on the side that it meets with the manifold in order to bring a little more exhaust and compress it to increase the velocity of your exhaust to spool the turbo quicker. My best advice get the Invida, it doesn't cost an arm and a leg, and the flanges are super thick so leaking isn't going to be an issue. Also it comes with brand new studs to put on your turbo, so u dont have to reuse the stock stressed ones. :D
 
#7 ·
The flex joint makes things easier for installation but causes turbulence in the exhaust flow, and is prone to break down and leak at the flex section. I would go with a name brand over the Ebay no name stuff. The Ebay quality is hit or miss. Some people have good luck them and some do not. I had a Perrin UP and now an Invidia UP modded for EWG. Both have fit great with no leaks and do not have a flex section.
 
#8 ·
getting a large diameter upipe will cause the exhaust gas's to slow down a little bit..stay with stock diameter unless you are going with a huge turbo (35r or something like that)...just do a lot of research when buying your uppipe because there are a lot of less than great ones out there that will start leaking at the flex joint.
 
#9 ·
I purchased an ebay UP without the flex joint in for about $50 shipped. Came with new studs and a plug for the bung. Whatever you do, though, I would suggest picking up some OEM gaskets to go on there as the new ones tend to go out pretty quick. Other than that I have no complaints.
 
#11 ·
and, should i buy new gaskets for the UP, DP when i get them? I looked at the HKS UP on ebay, and the pic they took shows gaskets with the UP, does it come with it?
 
#14 ·
alright thanks. and thanks for the gasket link. They should sell the gaskets with the UP and DP though. kinda ### you gota get em seperately... but w.e
 
#16 ·
So, i should replace all the gaskets when i do the UP and DP swap huh? just because it would be easier not to have to do it later... I'm pretty settled on the Invidia UP now, good quality for the price...
 
#21 ·
Quote:
Originally Posted by Boober909 View Post
oh and 3 inch is good but i don't think it matters a huge bunch.
FYI, people have made 800whp on a 2.25" uppipe and it wasn't a restriction.
But mosc....there ARE no 3" uppipes. Are there?

And for that matter...a 2.25" inlet uppipe is pretty big (bigger than HKS/helix/BPM etc)....so I would sure hope it's not a restriction!
 
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