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Old 07-02-2012, 10:50 PM   #1
jhigs1220
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Default 06 impreza 2.5i mods?

i have a 2006 2.5i and i want to add some more mods but i dont know what to add. i have a cosmo sri and a cheap exhaust tip. ill put pics up later but any input is appreciated.
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Old 07-02-2012, 11:07 PM   #2
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Originally Posted by jhigs1220 View Post
i have a 2006 2.5i and i want to add some more mods but i dont know what to add. i have a cosmo sri and a cheap exhaust tip. ill put pics up later but any input is appreciated.
get uel headers, catback exhaust, coilovers, wheels, then slam it. 2.5i's are not made for power so you mine as well slam it
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Old 07-03-2012, 09:48 AM   #3
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What is your end goal with the car?
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Old 07-03-2012, 07:31 PM   #4
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like what hp wise, looks, feel.
and where car i find a uel header
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Old 07-03-2012, 08:15 PM   #5
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There is nothing you can do to add horsepower to the car. I put the STI catback on my car today. I paid $100 for it and it cost $65 to be cut welded and put on. It sounds a lot nicer but no power.

You can put a hybrid intake or short ram intake which isn't the best thing and it will sound different thats really it.

UEL headers will cause you to lose some power but sound nicer.
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Old 07-03-2012, 08:23 PM   #6
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There is nothing you can do to add horsepower to the car.
You can put a hybrid intake or short ram intake which isn't the best thing and it will sound different thats really it.

UEL headers will cause you to lose some power but sound nicer.
No. Just don't talk until you know what you are talking about.
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Old 07-03-2012, 08:51 PM   #7
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No. Just don't talk until you know what you are talking about.
My apologies. He can always drop in the turbo engine from an STI or just add a turbo and get his car retuned. Ya know, the cheap way.
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Old 07-03-2012, 10:21 PM   #8
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That's still wrong.
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Old 07-03-2012, 10:48 PM   #9
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i don't believe UEL headers can cause 'loss of power'. anything flows better than stock. this is a dyno from a dude on rs25 with his 07 2.5i. he had CAI, borla uel, high flow cat and i think a catback. i believe he also had an ecu reflash since now on the graph its running rich at low end and lean up top:



all that and he gained about 7hp. if you ask me save your money and focus on other aspects like handling. get stickier tires, add thicker anti roll bars, install coilovers and get a big brake kit.
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Old 07-04-2012, 01:04 AM   #10
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definetly put a set of headers on plus a high flow cat and a sports rear muffler , not too big though. what you must do is stick with an exhaust pipe system of 2 to 2 1/4 inches diameter not 2.5 inches plus but 2 1/4 max. [ 2.250 ] we just fitted a set of UEL Borla rep headers / high flow cat and twin tip sports muffler which has a 2 inch inlet and 2 x 2.250 outlet tips to my sons forester NA and there is a definate increase in power output without doubt.
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Old 07-04-2012, 03:04 AM   #11
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my advice to you is to do your own research. if you're on a budget like most of us with N/A's you will probably lean toward suspension mods, but you shouldn't listen to me. RESEARCH
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Old 07-04-2012, 08:25 AM   #12
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Pickler, Subaru switched to EL headers in a hope to get some gains.. UELs won't help at all, IMHO. I agree though... 7hp is not a lot anyways. No butt dyno can feel a 4% increase - the wallet will definitely fell lighter after all those mods.

Also, the exhaust is limited by its most restrictive element so even if you put massive U&EL headers and a melon launcher with the stock cat, you're still limited by the stock cat.

To complicate matters further, tweaking the exhaust can sometimes free torque at peak RPM, while reducing it at low RPM - fun for dyno numers, worse for everyday driving.

OP - there is an array of upgrades offering arguably more bang for the buck if you drop the "moar horspower" viewpoint. Shifter, swaybar, tires, headlamps, mudflaps, suspension raise, suspension drop... you name it.
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Old 07-04-2012, 08:54 AM   #13
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basically, if you want to make noteworthy, noticeable power gains you will have to spend $1000+, plan on $1500 to include a tune. And that is for the minimum, assuming you are doing the work to install parts. If big power is truly the goal, a powertrain swap or vehicle trade is the cost effective way to go about it.

Huge improvements in driveability can be had with just a tune on stock parts, and a 20% bump in power just about everywhere can be had for a couple grand. after that the cost to gains ratio goes way down.

Just about everything that can be done to a WRX/STi can be done to the 2.5i chassis as far as other than powertrain mods, so if that is of interest do some reserach in other sub-forums, on other sites, etc. We have enough "how do I do this?" threads from forum n00bs so I assure you that your question/interest has probably already been discussed.
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Old 07-04-2012, 04:16 PM   #14
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Hp cost money but it is still available for na's. You could cam it, pump up the cr, open up the exhaust and tune it. You would see gains but it would not be cheap. You could also lighten the rotating mass to free up some torque.
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Old 07-05-2012, 09:11 AM   #15
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Originally Posted by mod maniac View Post
Hp cost money but it is still available for na's. You could cam it, pump up the cr, open up the exhaust and tune it. You would see gains but it would not be cheap. You could also lighten the rotating mass to free up some torque.
For freeing up rotating mass I would recommend acc pulleys and the crank pulley but that's it. I put a lightened flywheel in mine and I have grown to hate it. It makes rev matching much easier but the car bogs down like crazy under high load/low speed conditions (as in auto-x and rally-x).
Cams and a good tune will get you plenty of power where you want it and sink some money on suspension and good rubbers and your car will easily keep up with stock wrx's on track days .
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Old 07-05-2012, 11:29 AM   #16
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WHY WHY WHY! do people first talk about How a N/A subaru engine costs way too much to mod up to higher HP, YET THEY KEEP TALKING ABOUT IT.

Switch the conversation to how he can make the car handle better, instead of having a pissing contest on how you can gain 7hp with 2k of mods and some luck.

This is the N/A Forums Section, YOU should know not to talk about power gains in here.
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Old 07-05-2012, 12:56 PM   #17
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Quote:
Originally Posted by mrchyes
WHY WHY WHY! do people first talk about How a N/A subaru engine costs way too much to mod up to higher HP, YET THEY KEEP TALKING ABOUT IT.

Switch the conversation to how he can make the car handle better, instead of having a pissing contest on how you can gain 7hp with 2k of mods and some luck.

This is the N/A Forums Section, YOU should know not to talk about power gains in here.
Who are you talking to? Why would anyone switch the convo to handling mods in the N/A powertrain forum? We're still talking about power mods because this is the place where that info is discussed. The fact that it's expensive and arguably foolish to mod the n/a ej engines is besides the point of this discussion.

Also, piss off if this conversation bothers you.
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Old 07-05-2012, 01:25 PM   #18
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Originally Posted by mrchyes View Post
WHY WHY WHY! do people first talk about How a N/A subaru engine costs way too much to mod up to higher HP, YET THEY KEEP TALKING ABOUT IT.

Switch the conversation to how he can make the car handle better, instead of having a pissing contest on how you can gain 7hp with 2k of mods and some luck.

This is the N/A Forums Section, YOU should know not to talk about power gains in here.

That 7hp you are talking about is from bolt-on's. There are na motor's that put out just as much hp as stock wrx's but with a better power curve. That isn't achieved with bolt=on's you have to build the motor. when it takes $3500.00 to build a wrx then $3500.00 on a na isn't to much to spend for some good gains. Clearly some of you have never owned a fast na, I have and I am sure i am not the only one.
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Old 07-05-2012, 05:10 PM   #19
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That 7hp you are talking about is from bolt-on's. There are na motor's that put out just as much hp as stock wrx's but with a better power curve. That isn't achieved with bolt=on's you have to build the motor. when it takes $3500.00 to build a wrx then $3500.00 on a na isn't to much to spend for some good gains. Clearly some of you have never owned a fast na, I have and I am sure i am not the only one.
correct me if im wrong but won't 3500 get you an avo turbokit? additional $1000 for a bigger injectors pumps and installation?
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Old 07-05-2012, 05:36 PM   #20
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Quote:
Originally Posted by Pickler

correct me if im wrong but won't 3500 get you an avo turbokit? additional $1000 for a bigger injectors pumps and installation?
The most recent build I've seen on the forced induction N/A cost the guy 5625.00
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Old 07-05-2012, 09:24 PM   #21
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correct me if im wrong but won't 3500 get you an avo turbokit? additional $1000 for a bigger injectors pumps and installation?

I only said $3500 because that is what I spent on my rex, I"m sure I could build an na for cheaper. We were also talking na power not forced induction. The responsivness and better power curve of a na is alot more fun too.
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Old 07-07-2012, 02:23 AM   #22
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id say leave it stock, engine wise...except for intake and pulleys. other than that get an exhaust, coilovers, and nice wheels. then just keep working on the handling
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Old 07-08-2012, 01:28 AM   #23
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Spend your money on a new rear swaybar, then spend the rest on fuel to enjoy driving it. Save some money for a radar detector and speeding tickets
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Old 07-12-2012, 08:04 PM   #24
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So i have owned my 2.5i for a year, there slow rollers man just keep your up to date on basic maintenance make sure you do the timing belt, valve cover gaskets, spark plug well seals, spark plugs, shift bushings, just basic things to keep the car running forever.

hp gains are near impossible without spending around $1500-$3500

my friends built a hybrid motor it was sti heads and a turbo on our block it runs good but it cost him a nice chunk of change so...
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Old 07-21-2012, 04:00 PM   #25
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No butt dyno can feel a 4% increase - the wallet will definitely fell lighter after all those mods.
Really? That's like saying a typical family wouldn't notice a 4% raise. That's an extra $250 in their checking account every month. Four percent isn't huge, but it's detectable. As for whether 4% can be attained reasonably, that's another story; but if you can get 4%, it's significant enough.

Personally, I wouldn't try to make the newer 2.5 n/a any faster with so-called bolt-on modifications. I think we agree on that. I'd go for nitrous oxide, although I personally haven't been able to find a setup that I'd feel comfortable installing. There is one big problem: the returnless fuel system makes it difficult to introduce the extra fuel necessary to run nitrous oxide safely. The PCM is very precise about the amount of fuel it brings in from the tank, and there's no easy way to make it bring more... that I know of, at least.

I haven't really explored these questions fully, because I find the car to be reasonably fast as-is. The 0-60 and quarter mile times people report for these cars don't completely reflect this, but it comes out in other acceleration numbers (like the ones designed to measure passing ability).

I would like to do something to make the car lean less under hard cornering; but, having said this, I think its cornering limits are already quite high.
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