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Old 12-06-2012, 02:48 AM   #1
Bestdayever
Scooby Newbie
 
Member#: 336394
Join Date: Oct 2012
Location: Tennessee
Vehicle:
2002 Subaru
WRB

Default I've been on enough forums to know all the noobs ask this question, but...

I just traded my 91 Mr2 n/a 5MT for a WRB 02 WRX 5MT. Got a good deal on it, let's just say it has, "enough miles" for the trade, but nonetheless, a broken WRX is worth more than a broken mr2 n/a, so either way I came out on top.

I don't wanna be one of those ricer kids on the forums that everyone laughs at, cause they don't know the first thing about cars cause daddy bought them a car, but I work at a parts store, and I've been in school for the GM program for over a year, so I can work my way around an engine bay(usually, first time on a flat-4 though). Used to own an 03 Saab 9-3 with a full page of Mods(upgraded turbo, tune, lowered, the whole deal) so a WRX is for sure new to me(never got on the 9-2x forums)

So my questions are basically this:
-What kind of power is safe on a ej20 USDM with ~150k miles, what is the best setup for me?(I have a perrin intak, FMIC kit, TurboXS RLF BoV, full 3" exhaust no cat, I assume I am tuned because I have no CEL, the 2 kids before me didn't know squat about the car), I heard vf39 and 18g set up, but I am in middle TN, and there are NO awd tuners for Subaru's around me, so i'd rather go with something COBB has available.
-I'm on H&R coilovers, and have the usual ROTA 17x7 rims, with a WRB body and gold rims, what size tire will look the best, AND be able to launch, I have 225/55/17 on now and I bog out like a SO*)
-Lastly, whatever the answer is to the first question, what are ALL mods I need for a COBB AP tune? I have been lurking for awhile, and haven't found one..



Much appreciation, and here is a pic of my car before the gold rims.

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Old 12-06-2012, 03:18 AM   #2
Viral E
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Member#: 242246
Join Date: Mar 2010
Chapter/Region: RMIC
Location: Montana + Indiana
Vehicle:
2002 Impreza WRX
WRB

Default

Cobb or a Tactrix E-tune. Go Cobb if you like adjusting on the fly and ease of use. Go Opensource (Tactrix) if you want to save some cash and have a bit more tuning/logging options

As for power... As an owner of almost the exact same car I'll put it this way: The weak points I hear about on our cars are the fueling, intercooler (too small), the transmission, brakes, engine bearings and valvesprings/retainers are somewhat weak as well. I have also heard that our radiators are a little small, but I'm not sure if it's really of a huge benefit to change that with a FMIC.

I assume with an 18G or vf39 setup you are probably already running better fueling. You have the intercooler taken care of, and radiator is unimportant. That leaves the Trans, brakes, and engine bearings/valvesprings. The 5MT has been known to fail once you pass 300 bhp and push it too hard. I've heard explanations ranging from the input spline to the gears to the trans case itself. Honestly, the best explanation I've heard ran something like this:

The 5MT has fairly strong gears, and the case flex actually meshes the gears closer together (has to do with the geometry of the layout)... what really f's up the 5MT is the input shaft(s). It's a two-piece system. Apparently this is prone to catastrophic failure. Also, I guess the synchros are rather weak and fail quickly if you don't rev match and shift it hard or try to "force" the gears.

Personally, if you're going to drop any money, get stronger gears/input shaft and then replace your brake system with something a bit more... beefy. I've had brake fade in a passing lane and let me tell you.. IT IS SCARY!

As with everything, it's user-dependent. If you slam through gears daily and don't use your clutch as a sort of "buffer" between Engine and Trans, you're going to break something. 150k is getting up there, but then I've got 168k and all I ever hear is a bit of piston slap. Nothing serious.
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Old 12-06-2012, 07:35 AM   #3
quazimoto
Scooby Guru
 
Member#: 70395
Join Date: Sep 2004
Chapter/Region: MAIC
Location: Da-boonies,Va
Default

Quote:
Originally Posted by Bestdayever View Post
So my questions are basically this:
-What kind of power is safe on a ej20 USDM with ~150k miles, what is the best setup for me?(I have a perrin intak, FMIC kit, TurboXS RLF BoV, full 3" exhaust no cat, I assume I am tuned because I have no CEL, the 2 kids before me didn't know squat about the car), I heard vf39 and 18g set up, but I am in middle TN, and there are NO awd tuners for Subaru's around me, so i'd rather go with something COBB has available.
-I'm on H&R coilovers, and have the usual ROTA 17x7 rims, with a WRB body and gold rims, what size tire will look the best, AND be able to launch, I have 225/55/17 on now and I bog out like a SO*)
-Lastly, whatever the answer is to the first question, what are ALL mods I need for a COBB AP tune? I have been lurking for awhile, and haven't found one..
Well you know what happens when you assume...... Cobb's website has the mapnotes. They give you all the information about the maps including required mods. Grab a drink and some snacks and start reading.....
http://forums.nasioc.com/forums/showthread.php?t=533787

Like every other car forum,there is a FAQ/sticky at the top of every subforum
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Old 12-06-2012, 04:21 PM   #4
Tenament
Scooby Newbie
 
Member#: 246813
Join Date: May 2010
Chapter/Region: NWIC
Vehicle:
'02 WRX
WRB ::

Default

While I agree with most things you say Viral, case flex on the 5MT actually does the opposite, where under flex the gears "float" away from each other, resulting in less surface area, which equals bad.

Also, 2nd gear is notoriously long in the 5mts, and being the most frequently broken gear, is subject to shear stress. This is illustrated by this analogy:

You can pick something very heavy up with your fingertips for a short amount of time. However, the more time spent, the exertion becomes exponentially more difficult.
The same happens with long gears- the more time spent in that pressure, the more shear stress enacted on the teeth.

I know you guys know what I'm talking about- anyone who's moved knows how one can pick up absurd items with their fingertips for a very, VERY short amount of time, and any time after that short period is excruciating

Also, the 5MT is an outdated design. Porche-designed 6mt, coupled with shorter ratios given by the 6 speeds, gives a very drastic performance and reliability report than their 5mt counterparts.

Oh and OP, I'd suggest talking to Brandon at XPT tuning (http://www.xpttuning.com/). Their prices are very reasonable, and for a fraction of the cost of a COBB setup, you can have a custom-tuned map for you. He works with you over his forums and fine-tunes any map bought by his company. I am running their stage II tune w/ MBCS and for $50, I couldn't find a better deal.
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Old 12-06-2012, 04:57 PM   #5
ScoobySubyDoo
Scooby Newbie
 
Member#: 329311
Join Date: Aug 2012
Chapter/Region: Tri-State
Location: PITT/Collegeville, PA
Vehicle:
2003 WRX
Satin Black

Default

Tenament, so did you tune it yourself based off of what Brandon told you? I am confused. I just saw $50 and was like OMG I WANT

Sorry to thread jack
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Old 12-06-2012, 05:06 PM   #6
HinshawWRX
Medium Frank
Moderator
 
Member#: 140114
Join Date: Feb 2007
Chapter/Region: MAIC
Location: Common Sense, VA
Vehicle:
2014 Porsche
GT3 (Currently on Fire)

Default

http://forums.nasioc.com/forums/showthread.php?t=533787

As already stated, everything you will need to know. Start doing research. No need asking these, or at least in this section.
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