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Old 02-01-2011, 09:10 PM   #1
lllarrolll
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Default 2010 Advice! New Guy!

Hello everyone!

I just picked up my Impreza 2.5i Sedan in Oct. And joined Nasioc about a week ago or so, and I've been doing alot of reading on the forums trying to get as much info as I can so I don't come off as a complete n00b. Only mods I have done so far is a SRI custom made, but it kept setting off CELs about running rich. So I converted it back to stock :/ And I also threw on tints, and NGK plugs, $15 dollar ones. I have big plans for my baby! So any and all advice would be awesome. I will post pics once it stops snowing here in CT and I can wash my car.

Ok, so I've read alot that there isn't much more HP we can get out of our N/A engines. I'm putting a hybrid intake in it tomorrow, I would really like a Cosmo SRI or CAI, love the sound. But I don't think I can do it without setting off CELs. Though a few people on here say they have it with no CELs. Def do not want to spend $150 on an intake and have it set off a CEL. So I will hybrid it up for now. Next will be a cat back exhaust. I like the sound of the Stromung. Do others sound better? What size should it be, I hear 3" is good, but then I hear 2.25" or 2.50" is better for performance. Also the 2010s are dual exhaust, do I keep dual cat backs or how does that work? Def need some advice on that. After those two, I'll have it get tuned. What's the price range on a tune go for?

When my income tax check gets here, its going straight into the handling. The stock 2010 is so soft and squishy. Doesn't feel stable at speeds over 90 MPH. So, I plan on ordering the Rallitek Sway Bar Kit (Front & Back), Front and read strut braces (Need some good advice on this, prices range alot in this category, so a good brand? Material?), Front & Rear HD Endlinks from Rallitek, Rallitek Lowering Springs, Read Diff. Bushings, and Steering Rack Bushings. How's all that sound?

Also I noticed the brakes are squishy, don't really like it. How can I improve my brake system?

I have plenty more questions, but those can wait till I get this stuff done. And I would appreciate all advice and thanks in advance everyone!!

Also, let me know if my post is too long or if I'm saying the wrong stuff, I'm here to learn
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Old 02-02-2011, 12:08 AM   #2
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Old 02-02-2011, 01:11 AM   #3
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Quote:
Originally Posted by lllarrolll View Post
Also I noticed the brakes are squishy, don't really like it. How can I improve my brake system?

Pads, quality brake fluid, and stainless steel lines brake hoses will make it feel much better.
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Old 02-02-2011, 01:13 AM   #4
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Originally Posted by T Wrex--OH View Post
Pads, quality brake fluid, and stainless steel lines brake hoses will make it feel much better.
How about slotted rotors also?
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Old 02-02-2011, 01:31 AM   #5
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About brakes:
http://forums.nasioc.com/forums/show....php?t=1998265
Read this.

If you get a hybrid intake you're going to need a tune from what I understand. Read:
http://forums.nasioc.com/forums/show....php?t=2126588

and

http://forums.nasioc.com/forums/show....php?t=2125934
And read the sticky that is linked to in this one. Or just go to the top of the N/A section.

Exhaust: From what I have read any WRX exhaust for the same year and body style should fit the N/A. You don't have dual exhaust. You have dual tips on one muffler.

Suspension: Rear sway bar is going to be the best bang for your buck upgrade. Lowering springs and such are up to you. Seems like a lot of money to me. But then again, I'm not payin' for it so knock yourself out.

(And why are are you driving over 90, anyway? Slow down)
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Old 02-02-2011, 08:49 AM   #6
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Exhaust: From what I have read any WRX exhaust for the same year and body style should fit the N/A. You don't have dual exhaust. You have dual tips on one muffler.

wrencher, I believe sedans do have dual exhaust.

Tires make a big difference in braking. Your stock RE92's? suck.
Slow down. Your car was never meant to be a race car.

Last edited by jeonster; 02-02-2011 at 09:00 AM.
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Old 02-02-2011, 08:59 AM   #7
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Oh, sorry. I was thinking of the STi.

It's still not exactly "dual exhaust". It has one pipe that goes to a Y pipe right at the rear axle.
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Old 02-02-2011, 10:33 AM   #8
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Its "dual mufflers"
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Old 02-02-2011, 11:42 AM   #9
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Quote:
Originally Posted by lllarrolll

How about slotted rotors also?
Slotted or drilled rotors will make no perceivable difference in daily driving. New fluid, pads, and SS lines will improve the initial bite of the brakes, but they won't make you stop in a shorter distance.

Of course, if you like the way they look, that's a different story.
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Old 02-02-2011, 04:31 PM   #10
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Originally Posted by Wrencher86 View Post


(And why are are you driving over 90, anyway? Slow down)

I don't speed all the time, but if it's late at night and the highway is empty, I like to feel what my car is capable of.

One other question, what octane gas should I be using? I have been putting 93 in from day one. I hear it has cleaning chems in it and keeps the engine insides clean? Is this true, or am I just wasting my money?
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Old 02-02-2011, 04:35 PM   #11
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Originally Posted by jeonster View Post
.

Tires make a big difference in braking. Your stock RE92's? suck.

Can you tell me what I should be looking for in a tire? I was thinking of getting an 18" rim, but other than that I don't know about that other stuff (225/35/65) or what not. And is 18" ok? Won't hit the inside of the wheel walls? Thanks!
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Old 02-02-2011, 05:25 PM   #12
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Re: Tires - set the $$ aside so that when you buy a nice perfomance summer tire, you can also buy a set of winter tires and wheels. If you are going to invest in tires (IMO) get two sets so that you don't have to compromise for the seasons.

Your list of suspension mods sounds good, many people recommend similar mods. I wouldn't bother with the intake at all, a panel filter from AVO will give you a bit more sound if you want it. The OEM intake already takes air from outside the engine bay, so it's a CAI and is pretty efficient. You will get more bang for your buck from other mods.

You should be able to find a used 08+ WRX cat-back for pretty cheap on NASIOC or 3GWRX.com. If you spend more than $150 you are spending too much. Be patient, I've even seen them listed free/get this out of my garage. Buy local, as shipping is spendy for something that big.

Brakes: As recommended above, start with the lines, pads and fluid. This will make a big difference for a smaller investment of $$ and if you still don't like it you can move up to bigger brakes later. The lines will still be good and the fluid will eventually get replaced anyway, so at most you are risking the cost of pads.

You might consider a tune at some point. It won't get you HP, but a good tuner can re-map your throttle response and make a big difference in the "fun-to-drive" factor for the car.

Don't let your enthusiasm get the best of your wallet. If you do your mods with some time in between them, or in smaller groups, you'll be better able to direct where you want to go for the next step, and move it closer towards what you actually want. Right now you know what you think you want the car to do, but you don't really know if those mods will get you there. If you just do all the mods that people say are great and recommend, you may still not end up where you think you should be, because they all may want something different form their car than you do from yours. "Good handling" means different things to different people.

You may find that you are perfectly happy with the handling and ride with only 1/2 those mods. You may find the ride too harsh with them all installed. That leaves a bunch of money to be spent elsewhere. (Sound system, lights, wheels, girls, vacation?)

Personally, I find it more impressive when someone tailors their car to where they want it to be, and doesn't just plow all the usual stuff onto their car. IMO you should be sure that you are modding the car to be the way you want it to be and becuase you see a need for those mods, and not just buying mods because someone else said they are great.
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Old 02-02-2011, 07:38 PM   #13
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Originally Posted by Ogden View Post
Re: Tires - set the $$ aside so that when you buy a nice perfomance summer tire, you can also buy a set of winter tires and wheels. If you are going to invest in tires (IMO) get two sets so that you don't have to compromise for the seasons.

Your list of suspension mods sounds good, many people recommend similar mods. I wouldn't bother with the intake at all, a panel filter from AVO will give you a bit more sound if you want it. The OEM intake already takes air from outside the engine bay, so it's a CAI and is pretty efficient. You will get more bang for your buck from other mods.

You should be able to find a used 08+ WRX cat-back for pretty cheap on NASIOC or 3GWRX.com. If you spend more than $150 you are spending too much. Be patient, I've even seen them listed free/get this out of my garage. Buy local, as shipping is spendy for something that big.

Brakes: As recommended above, start with the lines, pads and fluid. This will make a big difference for a smaller investment of $$ and if you still don't like it you can move up to bigger brakes later. The lines will still be good and the fluid will eventually get replaced anyway, so at most you are risking the cost of pads.

You might consider a tune at some point. It won't get you HP, but a good tuner can re-map your throttle response and make a big difference in the "fun-to-drive" factor for the car.

Don't let your enthusiasm get the best of your wallet. If you do your mods with some time in between them, or in smaller groups, you'll be better able to direct where you want to go for the next step, and move it closer towards what you actually want. Right now you know what you think you want the car to do, but you don't really know if those mods will get you there. If you just do all the mods that people say are great and recommend, you may still not end up where you think you should be, because they all may want something different form their car than you do from yours. "Good handling" means different things to different people.

You may find that you are perfectly happy with the handling and ride with only 1/2 those mods. You may find the ride too harsh with them all installed. That leaves a bunch of money to be spent elsewhere. (Sound system, lights, wheels, girls, vacation?)

Personally, I find it more impressive when someone tailors their car to where they want it to be, and doesn't just plow all the usual stuff onto their car. IMO you should be sure that you are modding the car to be the way you want it to be and becuase you see a need for those mods, and not just buying mods because someone else said they are great.

Great reply! Thanks Ogden! I'll def. give it some more thought! Yeah once I took out the stock intake before with my custom SRI, I noticed it was already CAI. I just want that grow when I spike the RPMs! And does the WRX catback sound as good or better than the Stromung or 3" SRS N1 Style? And am I right to assume I should go with a 2.25 or a 2.50 for the catback?
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Old 02-02-2011, 09:10 PM   #14
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The OEM WRX cat-back will not change much in the way of sound. 2.25-2.5" is widely considered to be optimal for the 2.5L NA engine in terms of performance. Going bigger will give you more sound, but some say it comes at the expense of low end power.
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Old 02-02-2011, 10:34 PM   #15
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Originally Posted by lllarrolll View Post
Great reply! Thanks Ogden! I'll def. give it some more thought! Yeah once I took out the stock intake before with my custom SRI, I noticed it was already CAI. I just want that grow when I spike the RPMs! And does the WRX catback sound as good or better than the Stromung or 3" SRS N1 Style? And am I right to assume I should go with a 2.25 or a 2.50 for the catback?
Honestly you're not going to get the "growl" that you're looking for with intake mods. And you'll definitely get a louder car with a different exhaust, but still not much "growl".

If you really want that subaru growl you're going to have to change your headers to UEL and add a nice catback exhaust. (I won't go into much detail, but do a search, you'll find tons on this subject).

For my 2010 2.5i I just added the Perrin short shift adapter, and shifter bushings. This won't add any suspension stability, but it made my car feel 10X better when shifting gears. I absolutely LOVE the way that it shifts now. No more wishy washy gearing, no more play in the shift lever, and every shift feels super solid.

My next modification will be the Rallitek sway bar kit. Such a great deal to get some rigidity back in the frame. Eventually I want my car to be a suspension master, I could care less about power. That's the direction I'm headed in, kind of like Ogden said.
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Old 02-03-2011, 09:32 AM   #16
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Originally Posted by royalnewjersey View Post
Honestly you're not going to get the "growl" that you're looking for with intake mods. And you'll definitely get a louder car with a different exhaust, but still not much "growl".

If you really want that subaru growl you're going to have to change your headers to UEL and add a nice catback exhaust. (I won't go into much detail, but do a search, you'll find tons on this subject).

For my 2010 2.5i I just added the Perrin short shift adapter, and shifter bushings. This won't add any suspension stability, but it made my car feel 10X better when shifting gears. I absolutely LOVE the way that it shifts now. No more wishy washy gearing, no more play in the shift lever, and every shift feels super solid.

My next modification will be the Rallitek sway bar kit. Such a great deal to get some rigidity back in the frame. Eventually I want my car to be a suspension master, I could care less about power. That's the direction I'm headed in, kind of like Ogden said.

Yup, read all about the UEL Headers. Not too good for our N/A cars though. So I'll just get some good EL Headers if they come out with some! But yeah like I said I know I'm not getting alot of power out of the engine, but def going to have it handle like a god! Lol, hopefully this summer when I get vacation time, I want to take it out to Lime Rock. It would be a first for me. And I thought it was just my car that felt like squishy gearing lol. Sounds like stiffer bushings and a short throw would fix that. What brand did you go with? And for an exhaust I just want that deep sounding, not the civics rc sound heh..
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Old 02-03-2011, 02:28 PM   #17
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Quote:
Originally Posted by lllarrolll

Yup, read all about the UEL Headers. Not too good for our N/A cars though. So I'll just get some good EL Headers if they come out with some! But yeah like I said I know I'm not getting alot of power out of the engine, but def going to have it handle like a god! Lol, hopefully this summer when I get vacation time, I want to take it out to Lime Rock. It would be a first for me. And I thought it was just my car that felt like squishy gearing lol. Sounds like stiffer bushings and a short throw would fix that. What brand did you go with? And for an exhaust I just want that deep sounding, not the civics rc sound heh..
I don't think that the UEL headers are "bad" for our cars. Sure it won't add any horses, and may even change the power band a bit, but it definitely won't hurt the engine if done right. Put on a set of UEL headers, some type of WRX cutback exhaust, maybe a resonator and you'll have a deeper throaty growl.

As for the short shifter, I bought the Perrin short shift adapter with shifter bushings. It's not actually a new shifter, it's an adapter that fits on your current shifter and changes the throw by using a different fulcrum. Look it up on their website, it's really cool. It's also adjustable so you can keep it as stock as possible (while still decreasing throw and improving feel) or go as short as you want. Plus is like half as much as buying a new shifter.

Plus they give you bushings too, which made shifts feel 100X better than stock. I highly recommend it. Best mod for my money so far.
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Old 02-03-2011, 03:57 PM   #18
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I run the AEM CAI from rallitek for my 2009 2.5i hatch and a tsudo n1 catback system made for the wrx hatch (3"). no CEL. I also have a 22in perrin RSB and the Rallitek fsb for nonturbos. I also have eibach springs on the stock struts.

Noticible power? not really. Maybe going from 5k to redline is slightly more rapid.
The suspension set up? feels solid. Very tight around on/off ramps and mountainous roads. Makes it more fun to drive. Do i wish i had a wrx? yes. But am I happy with my 2.5i, hell yea.
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Old 02-03-2011, 05:12 PM   #19
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Originally Posted by royalnewjersey View Post
I don't think that the UEL headers are "bad" for our cars. Sure it won't add any horses, and may even change the power band a bit, but it definitely won't hurt the engine if done right. Put on a set of UEL headers, some type of WRX cutback exhaust, maybe a resonator and you'll have a deeper throaty growl.

As for the short shifter, I bought the Perrin short shift adapter with shifter bushings. It's not actually a new shifter, it's an adapter that fits on your current shifter and changes the throw by using a different fulcrum. Look it up on their website, it's really cool. It's also adjustable so you can keep it as stock as possible (while still decreasing throw and improving feel) or go as short as you want. Plus is like half as much as buying a new shifter.

Plus they give you bushings too, which made shifts feel 100X better than stock. I highly recommend it. Best mod for my money so far.

I think I read somewhere in the forums that UEL Headers on N/As mess up the back pressure or something and we actually lose power. Going to have to go order a short throw now since everyone has nothing but good things to say!
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Old 02-03-2011, 05:15 PM   #20
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Originally Posted by Dudestranded View Post
I run the AEM CAI from rallitek for my 2009 2.5i hatch and a tsudo n1 catback system made for the wrx hatch (3"). no CEL. I also have a 22in perrin RSB and the Rallitek fsb for nonturbos. I also have eibach springs on the stock struts.

Noticible power? not really. Maybe going from 5k to redline is slightly more rapid.
The suspension set up? feels solid. Very tight around on/off ramps and mountainous roads. Makes it more fun to drive. Do i wish i had a wrx? yes. But am I happy with my 2.5i, hell yea.
No CEL with the CAI? Does it still have the same problem as the others? With the running too rich then lean? Yeah, I want a 2011 WRX so bad, they look so mean now! But I am happy with my 2.5i atm. Just have to make it more fun to drive!
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Old 02-03-2011, 06:55 PM   #21
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Originally Posted by lllarrolll View Post
I think I read somewhere in the forums that UEL Headers on N/As mess up the back pressure or something and we actually lose power. Going to have to go order a short throw now since everyone has nothing but good things to say!

Not quite. Read this:

http://www.thumpertalk.com/forum/sho...d.php?t=659727

Backpressure on newer cars is basically meaningless. Most people use the word "backpressure" when they actually mean "engine velocity". Basically like putting your finger over the top of a garden hose to increase the velocity of the stream. Sure, you can have a huge hose with lots of water, but it wont get you very far if there's no velocity and the water just dribbles out.

It's the same thing for our engines. Headers don't change the velocity all that much. What does change the velocity is putting a huge 3.5" piping and exhaust on a tiny N/A motor. The headers have to start around 2.5" (stock diameter) in order to bolt on to the engine, so it shouldn't change your power level dramatically, except maybe shift your power band down a bit (given that the air is now allowed to flow at different rates through each side of the header).


Last edited by royalnewjersey; 02-03-2011 at 11:34 PM.
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Old 02-03-2011, 09:46 PM   #22
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Originally Posted by royalnewjersey View Post
Backpressure on newer cars is basically meaningless. Most people use the word "backpressure" when they actually mean "engine velocity". Basically like putting your finger over the top of a garden hose to increase the velocity of the stream. Sure, you can have a huge hose with lots of water, but it wont get you very far if there's no velocity and the water just dribbles out.
Backpressure was always a myth, even on older cars.

Also, I'm assuming you meant exhaust velocity...

Quote:
Originally Posted by royalnewjersey View Post
It's the same thing for our engines. Headers don't change the velocity all that much. What does change the velocity is putting a huge 3.5" piping and exhaust on a tiny N/A motor. The headers have to start around 2.5" (stock diameter) in order to bolt on to the engine, so it shouldn't change your power level dramatically, except maybe shift your power band up a bit (given that the air is now allowed to flow at different rates through each side of the header).

Headers do affect the exhaust velocity, more so than the rest of the exhaust. A 3.5" axleback, while completely pointless, isn't going to have that huge of an effect on scavenging at the exhaust port.

The only way the stock headers have a 2.5" diameter is if you're talking about the OD of the collector, and that still sounds too big.
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Old 02-03-2011, 10:24 PM   #23
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headers designed to improve power have everything to do with exhaust velocity. the faster the exhaust gas moves and the length to and design of the collector (which is also designed to maintain velocity) are the things that should be considered when designing a useful exhaust manifold
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Old 02-03-2011, 11:15 PM   #24
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Originally Posted by lllarrolll View Post
I think I read somewhere in the forums that UEL Headers on N/As mess up the back pressure or something and we actually lose power. Going to have to go order a short throw now since everyone has nothing but good things to say!

Maybe you're confusing this with adding in your own turbo. That's horrible for pressure timing - the locations of the pressure gauges aren't in the correct places so you'd definitely loose power since timing would be incorrect.... does that sound right?
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Old 02-03-2011, 11:40 PM   #25
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Quote:
Originally Posted by renyo View Post
Backpressure was always a myth, even on older cars.

Also, I'm assuming you meant exhaust velocity...
Backpressure is definitely not a myth. It's just not the reason people should cite when talking about power loss.

If you look at my post I said "meaningless". Backpressure can indirectly cause lean / rich fuel mixtures, and our engines automatically compensate and adjust.

And yes, engine / exhaust velocity.

Quote:
Originally Posted by renyo View Post
Headers do affect the exhaust velocity, more so than the rest of the exhaust
What I meant to say was "headers don't decrease power that much". They can change how freely the exhaust flows, and where the power lies. But often they don't decrease power, which is what the OP was asking.

This is probably why Subaru has used UEL headers on their turbo cars for so long, to add some needed power in the lower RPM's and leave the turbo to add the power in the higher RPMs.

Last edited by royalnewjersey; 02-03-2011 at 11:48 PM.
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