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aftermarket up pipe realistically better?

10K views 26 replies 8 participants last post by  SilverSuby 
#1 ·
Ok I have a simple question about an aftermarket up pipe. I dont understand why everyone says that buying one is an upgrade. Your turbo relies on the velocity of your exhaust gas stream so if you enlarge the up pipe it slows down the stream flow, thus preventing fast turbo spool up. Just curious because I have the Invidia tbe, Spt intake, Sti tmic, Walbro 255cc fuel pump, Deatschwerks 650cc injectors, Blouch Evo III big 16g turbo, and I was debating on whether or not to get an up pipe but it doesnt seem to be a good idea. But everyone else gets them so I wanted to check.
 
#3 ·
The reason you get one is to delete the cat in the stock uppipe. Supposedly it can get sucked into your turbo, and BOOM

P.S. If I remember, most aftermarket Uppipes are the same diameter piping as stock.
 
#4 ·
Some aftermarket Up Pipes are bigger and those will create lag in favor of flow on the top end. Removing the cat will spool the turbo up a lot faster. In my research I had the same question and I made sure the aftermarket one I bought was stock diameter since I wanted responsiveness over top end power. The stock STi one does not have a cat and it is a viable option if you can find one used.
 
#5 ·
up-pipe's decreasing spool time is debatable. Dynos have shown the gain to be negligible. My own feelings is that it makes the exhaust slightly louder which translates into people thinking it adds power. It is a safety mod, not a power mod.
 
#10 ·
Oh definately! The Stage 2 map drastically improves spool on it's own.

And SilverSuby, don't risk that awesome turbo. You need an up-pipe without a cat in it. It's going to put out enough hot air to really risk damage to the CAT (which means crap flying into your turbo)
 
#11 ·
If you get aftermarket headers (or port the stock ones), the outlet diameter will probably be close to being gasket matched (2"). If your uppipe is stock diameter it will introduce a "step" in the piping and will become a restriction. How much of a restriction? I don't know, but I didn't want to find out so I bought an uppipe with a 1.9" inlet.

I've also seen pics of a disected stock uppipe, and the way the flex is designed didn't look good for flow at all...
 
#12 ·
If you want to spend real money on the hot side of the turbo, get yourself some P&P'd headers from grimmspeed with a high flow crossover and throw in their custom P&P'd Uppipe. It's kind of overkill for a 16G but might get 5-10hp out of it with a good tuner.
 
#17 · (Edited)
You should spend money on the intercooler imho. There's probably better gains from buying a bigger intercooler than in headers (exhaust manifold). Not that you couldn't do both... there's always more to do ;)

With your E3-16G, you really need:
Bellmouth Downpipe
Catless Uppipe
~650cc injectors
Fuel pump
BIG! TMIC

Headers, intake, and a CBE are nice but make sure you got those parts maxed first.
 
#19 ·
already have the bellmouth 3 inch tbe, already have the 650cc injectors(deatschwerks), already got the walbro 255cc pump, ordered the up pipe already and I said intake manifold, not the exhaust manifold, but Ill keep that in mind. Plus what size tmic we talking about, core size wise?
 
#20 ·
Whats your budget for that? Honestly APS makes an awesome TMIC, but spendy. TubroXS, Spearco are also huge TMICs. Search around for them to find the prices for them as I cant remember off the top of my head price or sizes of them.
 
#23 ·
Wait, so you are planning to buy a bigger intake manifold too? Is the stock intake manifold even a restriction? I don't recall ever seeing any WRX's, even highly modified, with an aftermarket intake manifold..... Maybe I just didn't see that mod..

If you don't have a budget really, then look into APS or Perrin. They are obviously more expensive, but you get what you pay for IMO, they are really nice units...
 
#24 ·
I don't think you want to mess around with the intake manifold. It's going to add lag believe it or not and it's not a restriction. Unless you're running a FMIC, I wouldn't consider an intake manifold. Do they even make ones that FIT with a TMIC? Are you just getting your stock one ported? I suppose that couldn't hurt. Are you sure you mean intake manifold and not exhaust manifold (headers)?

As for the TMIC, I would settle with either Perrin or APS. I believe the APS unit is slightly bigger but it's not as easy a fit. They're both about double the size of the factory STi cooler.
 
#25 · (Edited)
I mean the intake manifold and I wasnt buying it for performance, at least not only. They offer a black ceramic coating which I really like and its the same as stock minus a little porting. But if I remember correctly its not really ported persay, they just got rid of acouple spots that the air got held up on in the oem manifold. But mostly for appearance. But I went back and looked at the exhaust manifold and it tickled my fancy as well so Im debating as of now. I like the three peice design and it aslo can come in black ceramic.

GrimmSpeed
 
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