Subaru WRX Forums banner

1 - 20 of 31 Posts

·
Registered
Joined
·
336 Posts
Discussion Starter #1
Found this article on Car & Driver's web site. Thought it was interesting and suitable for this section of the forum. 2009 WRX ftw.

Source: http://www.caranddriver.com/buying_guide/subaru/wrx/2009_subaru_impreza_wrx_4_door/five_steps_to_making_more_power_in_your_subaru_wrx_gear_box

STEP 1: The Intake Trick

Getting more air into the engine’s combustion chambers produces more power, right? Right. After a simple installation, the low-restriction conical air filter and straight intake tube of the K&N Typhoon kit (800-858-3333; www.knfilters.com) gave us a 17-hp increase at the wheels and a new jolt of torque worth 21 pound-feet. The intake carries its own million-mile warranty and doesn’t void the factory warranty. The downside: It doesn’t meet California emissions regs, and the increased intake noise was hated by the old folks in our office.

STEP 2: The Exhaust Tactic

We were feeling pretty smart after installing a Magnaflow exhaust (800-824-8664; www.magnaflow.com). All it took was a few bolts and clamps, and the WRX was putting out a pleasant burble at idle without being too loud. Power was unchanged, but torque increased by 10 pound-feet. Like the intake, the stainless-steel exhaust is guaranteed for life and won’t void the Subaru warranty.

STEP 3: But They Don’t Add Up

We put our project car on a dynamometer with the K&N Typhoon intake and the Magnaflow exhaust (the numbers mentioned earlier were achieved with each performance piece installed solo on the WRX). With both installed, horsepower was up by 11 over stock and torque was up 20 pound-feet—increases that are less than those produced by the modified intake alone. The extra airflow on both ends was apparently too much for the factory ECU to cope with, and it compensated by cutting power right when the turbo reached maximum boost. Either the intake or exhaust works fine alone, but ECU modifications are required to get them to work in tandem.

STEP 4: Let’s Get Serious

So, to get even more power, we had the engine reprogrammed. Remember, that voids your powertrain warranty. We called Cobb Tuning (801-713-0035; www.cobbtuning.com) for its AccessPort, which can completely revise the engine software. And to further free up the exhaust, we threw in a Cobb downpipe with a high-flow catalytic converter. The AccessPort connects to the OBD II plug and automatically saves the factory engine programming. It also has preset engine maps for various states of tune, but none that accounts for an aftermarket intake. Cobb says there are too many variables to have a single program, so we got a $460 custom engine tune. After that, wheel horsepower was up 57 to 266, torque increased a staggering 68 pound-feet to 293, and now the engine sounds meaner than Sasquatch’s wife.

BONUS STEP: Getting a Grip

We installed a set of higher-performance Bridgestone Potenza RE-11 (www.bridgestonetire.com) tires, swapping out the stock Dunlop SP Sport 01s. Skidpad grip increased from 0.84 g to 0.87 g, with a noticeable reduction in the understeer that plagues the stock WRX.



 

·
Registered
Joined
·
3,474 Posts
Pretty ridiculous getting to stage 2 STi levels only with a pro-tune and intake + catback exhaust. WOW 2009 WRXs have a ton of potential. From 209- 265whp is pretty crazy.
 

·
Registered
Joined
·
537 Posts
Pretty ridiculous getting to stage 2 STi levels only with a pro-tune and intake + catback exhaust. WOW 2009 WRXs have a ton of potential. From 209- 265whp is pretty crazy.
Accept this is also stage II. You must have missted this lien from the article.
"we threw in a Cobb downpipe with a high-flow catalytic converter"

Still amazing numbers.
 

·
Registered
Joined
·
802 Posts
Mods - This would make a great sticky, especially since there's not very many mod vs. dyno results available for 2009's.
 

·
Registered
Joined
·
3,474 Posts
Pretty ridiculous getting to stage 2 STi levels only with a pro-tune and intake + catback exhaust. WOW 2009 WRXs have a ton of potential. From 209- 265whp is pretty crazy.
Accept this is also stage II. You must have missted this lien from the article.
"we threw in a Cobb downpipe with a high-flow catalytic converter"

Still amazing numbers.
I blame eye jump. LOL
 

·
Registered
Joined
·
2 Posts
Pretty ridiculous getting to stage 2 STi levels only with a pro-tune and intake + catback exhaust. WOW 2009 WRXs have a ton of potential. From 209- 265whp is pretty crazy.
Accept this is also stage II. You must have missted this lien from the article.
"we threw in a Cobb downpipe with a high-flow catalytic converter"

Still amazing numbers.

wow, the article really great in tackling about the catalytic converter. this was very helpful. just wanna ask what is the right thing to do to protect the catalytic converter from damaging?
 

·
Registered
Joined
·
71 Posts
i dont know how many people are going to respond, because this was from a long time ago, but i will chime in with another question. why would the cat be damaged ? unless that tune has a lot of backfire it really shouldnt damage that easy .
 

·
Registered
Joined
·
4 Posts
As a newbie '09 hatchback owner which would be a better first mod, intake or exhaust? It appears it is not beneficial to do both until you also get a tune. Is that correct? I am just starting and adding as I save up cash on the side. Any advice/input would be much appreciated!
Cheers,
 

·
Registered
Joined
·
7,947 Posts
usually its accessport or opensource
then full exhaust
will give you more power then an intake and you will not go lean or need anything but a basemap
 

·
Registered
Joined
·
5,664 Posts
As a newbie '09 hatchback owner which would be a better first mod, intake or exhaust? It appears it is not beneficial to do both until you also get a tune. Is that correct? I am just starting and adding as I save up cash on the side. Any advice/input would be much appreciated!
Cheers,
Go downpipe first with a stage 2 tune, and drop in a panel filter in your stock airbox.
 

·
Registered
Joined
·
4 Posts
Thanks for the info! This WRX is my DD so I am looking to beef it up some without going overboard. What kind of performance increase will a downpipe and tune get me? Is there a particular brand you would recommend? I appreciate the help.
 

·
Registered
Joined
·
13 Posts
just bought my new WRX. what do you think guys think the first mod should be? downpipe? cobb accessport? exhaust? intake? and what brands are considered the best?
 

·
Registered
Joined
·
30 Posts
I would personally go downpipe with accessport. I went cai then catback and you don't really get any noticeable gains. As far as brand goes, invidia makes quality downpipes but it's really up to you. Never heard anything bad about Cobb or perrin or any other brands. It really comes down to preference.
 

·
Registered
Joined
·
13 Posts
yea thats what i figured.. i think im going straight to stage 2 but not for awhile.. im still in the break-in stage so im gonna run stock.. what do u guys think of tweaking the suspension a bit? sway bars? coilovers?
 

·
Registered
Joined
·
30 Posts
I personally haven't done any suspension upgrades yet (gravel roads, rough winters), but I do know that when I threw the DP on, I haven't looked back. The power difference on stg 2 is unreal, and to me is more worthwhile.
 
1 - 20 of 31 Posts
Top