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Discussion Starter #1
I already got my 3in catback put on and now I am bit by the mod bug (I swore I wasn't going to void my warranty, now at 3k here it goes), so, I am trying to figure out, since I live in socal, how much louder would my exhaust be with a uppipe or downpipe, don't want to draw lots of attention to myself? I am not even trying to get a felony ticket for removing my cats, but do want more HP, so which of the 2 would you guys recommend?
 

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when my buddy added his exhaust in, it didnt really sound any different, just heard the turbo a little bit more, so its all good!!
 

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It's not the sound that will get you, it's the smell. If you go full catless you're gonna leave big stink behind you. ;)
Up pipe - gut your stocker or buy a gutted stocker. Same gains as an aftermarket and will appear at least on the outside to still be stock.
Down pipe - you can get down pipes with high-flow cats in place, or buy a turboxs downpipe with a high-flow cat section. There are plenty of options. Keeping one cat (the third, preferably) won't hinder performance too much.
 

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pjdwrx said:
It's not the sound that will get you, it's the smell. If you go full catless you're gonna leave big stink behind you. ;)
Up pipe - gut your stocker or buy a gutted stocker. Same gains as an aftermarket and will appear at least on the outside to still be stock.
Down pipe - you can get down pipes with high-flow cats in place, or buy a turboxs downpipe with a high-flow cat section. There are plenty of options. Keeping one cat (the third, preferably) won't hinder performance too much.
ya when i get mine all together, its going to be a perrin UP/DP and a catback exhaust. im keeping just 1 cat!
 

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AIRBORNEGUYWRX said:
ya when i get mine all together, its going to be a perrin UP/DP and a catback exhaust. im keeping just 1 cat!
Not with that setup you're not. ;)
Unless I'm mistaken (which is 1000% possible) the Perrin dp eliminates the 2nd and 3rd cats. You put that in and bolt up the rest of the cat-back section there are no cats left.
 

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i believe im leaving the 3rd cat in, just for purposes of smell. When i ran a completely open exhaust on my Lancer - it was the headers that made the difference in sound more than anything, not the downpipe or removing of the 2nd cat (car only had 2 cats)
 

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pjdwrx said:
Not with that setup you're not. ;)
Unless I'm mistaken (which is 1000% possible) the Perrin dp eliminates the 2nd and 3rd cats. You put that in and bolt up the rest of the cat-back section there are no cats left.
DP-no cat UP-no cat but i will have a cat between DP and exhaust pipe.......... or just keep my stock UP
 

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Just got the uppipe. This is a MUST DO mod for us 4EAT'ers. The car is actually driveable at low RPMs. This is the way the car should of come from the factory.

You can definatly notice a difference when you cold-start the car. After the first 5 or so minutes, the car smells just like stock.
 

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Discussion Starter #11
gutted stock uppipe is a good option since it shouldn't void my warranty, will still pass smog cause it looks stock, but I heard the install is a ROYAL bit%^, isn't it? I didn't notice any difference with my catback (I knew I wouldn't really though) but with an uppipe can you actually feel a difference?
 

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first, I must attempt to persuade you not to gut the stocker. It is a serious PITA! Trust me! I partially gutted a stocker, and if I could do it over again, I would just get an aftermarket one from the start. Since the ERZ uppipe can be had for under 100$, there really isn't too much of a reason to gut your uppipe anymore. Also, gutting your stocker will void your warranty, and yes, most dealerships will be able to tell it's gutted (checking for resistor, lack of EGT bung etc) If you still want a "stock looking" uppipe, look into the JDM STI uppipes (look stock). With most aftermarket uppipes and the gutted stocker, you will need a cel fix, either with a 2.2 Kohm resistor, or by upgrading to Cobb Stage 2 (automatically gets rid of CELs).

Yes, you will notice a difference. I didn't really notice a power gain, but I can hear the turbo spool now at around 2200 RPM, and I get usable boost at 2500 RPM. I can now keep my car in "D" most of the time instead of putting into "3" for times I need a little more "oomph." Not only that, but I am getting about 2 MPG better with the uppipe. I can not discribe enough how much this mod has improved daily driveability, it should be every 4EAT'ers first mod.

Edit: You do not want to keep your stock EGT bung, plug it with a m12x1.25 bolt . By keeping your EGT bung, I'm pretty sure your EGT sensor will send your car into "limp mode." there is also a chance it can break apart due to the higher EGTs.
 

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Discussion Starter #14 (Edited)
so I need to be ready to void my warranty before i do this? so a JDM uppipe looks stock? I want something when i go into smog it they won't be like, uh, there is supposed to be a cat there...


what if I can a gutted uppipe for cheap?
 

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More or less, you have to be prepared to kiss your warranty good bye. Legally, Subaru cannot void your warranty simply because you have aftermarket parts. They must prove that the mod caused the problem. Now what problems will a catless uppipe cause? More or less, none. (STI has a catless uppipe).

The smog place cannot really see the uppipe without taking some parts off your car first (which they will not do). I have never heard of anybody failing smog with just a catless uppipe.

If you can find a cheap gutted uppipe, that's fine, but why would you wan't that on your car when you can get an ERZ uppipe for the same price? ERZ uppipe combo + 2 new gaskets can be had for around 85+ shipping on Ebay. Gutted uppipe is at least 85+ you need to get your own gaskets, so it comes out to more. Plus the stocker has more turbulence due to the uneven airflow caused by the space where the cat was (not a big deal on stock applications, but caused a heck of alot of wastegate flutter in my case for some reason).

I had both on my car, and there really isnt a difference (maybe a little earlier spool and tiny bit more top end...nothing major). However, I think in this case. you're better off getting the ERZ uppipe (CHECK EBAY!!!)
 

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First off, I don't think that an emissions tech is going to look too hard for cats before the turbo.
Secondly, a gutted uppipe is the way to go, IMHO. If you have a long screwdriver, a hammer and a decent drill, you can get that cat out of there. Just be patient and don't rush yourself.
Third(ly), the install is a PITA, but not because it's hard to do, but because it take some time. Follow Perrin's or Vishnu's instructions and you'll be fine.
 

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Yeah, it's wierd. Some people seem to be able to do it in a couple hours, other's literally have to spend days on it (like me :mad: )

If you are doing the install yourself, and don't mind the fact that your car may be out of commission a few days, then yeah, try to gut it. I mean, it is the best free mod you can do to your vehicle, period. Before you attempt it though, I HIGHLY, HIGHLY recommend you have at least these parts.

-Hammer w/ sledge-like head.
-Power-drill
-12 inch drill bit
-12 inch drill bit extension
-respirator (cat is carcinogenic, and those dust masks don't do crap. I found out the hard way).
-1.5 inch polishing bit
-long screwdriver/railroad spike
-a set of metal grinding points
-gloves and safety glasses.

without at least these parts, you won't be able to get the job done.

if you are having the part shop-installed, then you need either a second uppipe to gut yourself/already gutted pipe or an aftermarket pipe. it's not something you can say "ok call me when you take out the uppipe, then i'll gut it and bring it back" lol.

IMO, unless you gut your own uppipe, it's not really worth it. Buying a used stock uppipe (50 shipped usually) + gaskets (30 for the two uppipe gaskets, 50 for a complete set) and you have reached the price of an ERZ uppipe (which is one of the better deals on the market, the vendor even includes two new gaskets).
 

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Removing your cats: adding up/down pipe WILL make more noise and dont believe otherwise, PERIOD. Will also add HP, so take it or leave it I guess

high flow cats- Hmm the cops will still give you crap and maybe a ticket anyway, so may as well go catless and get the hp if the cops give you hell with either

Upipe only, cops will never spot one, so if youre anal about the cops and only want one, go with the up

Down pipe, obviously is more significant (catless) in hp gains the the down but cops will notice the cats are gone

My opinion- have some balls, play the game or stay stock. Chances are you wont get any tickets for your pipe anyway. If youre going to go half way (high flow cat), just stay stock
 

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Snap up that used Helix in the private for sale thread that you asked him about.
See if there are any local SoCal guys willing to help you install it. Pizza and beer is all it will take.
You've got 200 and some change left to put to an AccessPort. :wiggles:
 
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