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2008 WRX Bolt-ons

9K views 17 replies 8 participants last post by  pzr2874 
#1 ·
Hey all, my name is Aaron, this is my first post and the WRX belongs to my G/F.

I've been using this and a few other forums as info resources over the last 2 months to gain some knowledge on this car before we pulled the trigger on any parts. I think overall this forum was my favorite to turn to when I needed some help though, which is why this is my first post reguarding the car on any site.


As for the car itself, it was totally stock before we started our modding.

The g/f had it before we started dating about 6 months ago and was pretty happy with it, but after a few complaints on my end after I had been driving it for a while I think she realized it's lack of urgency. I hated the poor throttle response, the turbo lag was too much for such a small turbo and once it did kick in it ran out of steam around 4,500 rpm. It felt and sounded like a turbo diesel.

She wanted the Boxer rumble and I wanted power so here is the list of parts we picked out to fix her Subbie's issues.

In order of installation:


-TXS intake

Cons -
It did not come with any directions, but the install was very simple so they were not really needed. However, I did not like the mounting bracket placement. It's in a spot that makes it impossible to tighten the nut down to really secure the pipe to the chassis. At this point it's near-tight, so we will see how it holds on there. The most annoying part of this part is not the build quality though, but the simple fact TXS did not include mounting screws for the sensor. The new holes are larger than the plastic pipes holes and are a different thread style. We luckily had one spare screw in the house that fit...I still need to find a second this week. Too me, this was not really exceptable.

Pros -
1. The finish of the pipe was very nice and the welds are clean, it also has a true K&N filter
2. It was the cheapest name brand intake on the market (still no excuse for missing hardware though)
3. It actually added a small, but noticeable increase in performance.
4. The previously unnoticeable turbo is now loud and clear, as well as the by-pass valve
(the g/f's favorite parts.) It sounds like its a turbo now!

Overall -
We are happy with the intake purchase. Just be prepared to spec out your own sensor screws.

-TXS catback

Cons -
1. Again, no directions. This time they would have been nice. I don't like playing tetris with car parts while trying to figure out which pipe goes where when i'm under the car. I want to know what's going on before I start the job. It saves a lot of time.
2. The fitment could have been better, there where a few moments when I was not sure it was all going to come together without taking it to a shop to have cutting done.
3. The hanger fitment is off. One of the muffler tips is hitting the bottom of the bumper on the pass side, while the other one hangs too far down. There is a metal part that came with the kit that looks like an adjuster, but because there are no directions I have no clue what it is. I'll have to call the vendor to ask.

Pros -
1. The finish and build quality are very impressive. The welds are super clean and it has almost a mirror finish. It does not match the cheap price at all.
2. The price! Again the cheapest name brand on the market.
3. The fit. Once everything was in place it came together nicely...for an aftermarket exhaust that is. I have seen much worse.
4. The sound. By far the best quality of this catback was the sound, it's not crazy loud and it's very deep and smooth. The g/f was thrilled when we fired it up for the first time. Iv'e got a video of that I will try to post.
5. Performance. Thanks to Subaru's poor craftsmanship of the stock exhaust, (I really mean one of the worst I have ever seen) this catback had a very noticeable boost in power. Throttle response was sharper, low-mid power was increased and the top end was a bit better as well, but still choked off.

Overall - If you don't HAVE to be a parts snob and buy the most expensive on the market just to say you did, then get this system. The tips will sit fine with $30-$50 at a shop to tweek the hangers.


-TXS downpipe/catted midpipe

Cons -
1. Fairly difficult to install. All due to the nature of the vehicle though, all downpipes share this problem. Install time was around 1 1/2 hours.
2. Fitment was a bit of an issue. Everything connected to the catback just fine, but due the the placement of the large resonator a body bolt protruding from the floorpan was hitting the resonator. This was not apparent until a test drive revealed a horrible noise/vibration. This was fixed by cutting down the bolt with a sawzall...and burning my arm on the exhaust.
3. Overboost code after hitting redline. Code cleared out after a few key cycles.

Pros - 1. THE POWA! Night a day difference over the stock parts. The car pulls much better throughout the curve, even on the top. Everyone should buy a bellmouth downpipe ASAP. Then tell your overbearing dealer to stick the stock pipe up his *** when he starts gripping about the warranty.
2. Fit + finish again are very nice, no issues here
3. Again the price...

Overall - This is a must have mod, now I understand why you Subaru owners go on and on about your downpipes. It's a downpipe thing

-Pro Sport Uppipe + Unequal header
Cons -
1. Time consuming to install. Again though, the nature of the car, not the brand.
2. I now have a Ph.D in tetris from installing this.
3. I dont really like Tetris
4. 3 hour install time...mostly due to finding parts/tools
5. Did not come with a way to close off the port in the uppipe...I will leave it at that, If I go into my feelings on this I will start offending people.
6. This install is a two person job without a lift, and is not suitable for an amature mechanic.

Pros -
1. The fit/finish are incredible. This is the crown jewel of the car, it's just too bad no one will ever see it.
2. Once the parts were all lined up and primed to go into their respective places the g/f and I were able to massage it into place fairly easily. (The trick is to attach the pipe to the turbo hand tight, then attach the pipe to the header hand tight, then bolt the header to the heads, then tighten everything down.)
3. More POWA!
4. The car sounds much meaner after these were installed.

Overall - The car revs very easy after this mod. The spool time is much faster, the low/mid end got a big bump in power and the top end is surprisingly good now too.

These installs were done over a 4 day period. Intake on first day, then the catback then the DP and finally the header/pipe.

I have no idea how much power these mods added, but the car is not the same anymore, it's actually fun to drive now and the g/f loves the way it sounds and the way it drives...and so do I. It will actually set you back in the seat now.

Can anyone give me a guesstimate of the awhp this untuned setup should currently have?
I'm also looking for some suggestions as to the next parts. I was thinking about an AVO TMIC, followed by a AMR cxr500 with 850 cc injectors and a walbro pump. Can anyone think of anything else? Meth is not an option though.
 
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#2 · (Edited)
Not sure on the power gains but i would get a tune asap. And i mean asap. You don't want to be adding lots of parts like that and not tuning for them. you will get lots more power and right now you are running a pretty good risk of engine damage. Your ecu still thinks you have stock parts on the car and is probably struggling to keep up. Between the intake and all that exhaust...man you are changing all kinds of air/fuel parameters. If it were me i would look into some kind of e-tune at the very least.




Ps tactrix cable-$170 and i would assume an e-tune would be under 200 not sure because i use an accessport and don't really have plans to do more than stage 2. But yeah i would take a look at the tuning and em faqs to see the importance. that car is pretty expensive to fix should it decide to take a d on her bc it isn't tuned for those parts. Oh and btw if you do those fuel mods without tuning you car will prob not run well at all. So my "next mod" would be the cable and tune if it were me.
 
#4 ·
At least get an aftermarket TMIC and tune this thing ASAP.

Personally, I'd just nab a VF52 from an 09+ WRX, TMIC, and Tune and see how happy that makes you. A CXR500 is a pretty big turbo for a stock block and I don't think you're ready for that yet.

Honestly you're maybe making 20hp over stock right now because the car currently hates it's life and is pulling timing like a mother. Once you tune you'll be making 50 or more over stock.
 
#5 ·
jesus!!! two months of reading and you had no idea adding parts like that is the biggest no no ever without a tune? ill be surprised the motor or something isnt blown already. hopefully that little snail is making no extra HP. the sad thing is your are so lean right now a blown piston ring is only a minute away even with the ECU pulling timing and boost.
 
#7 ·
I was really tired in the morning while posting, I did forget to mention that tuning will be taken care of very shortly.

The car has been to redline once and the mods have been on for about 4 days total. She is currently taking it easy on the car to and from work until we tune it, it's also on 91 oct as well.


I had also thought about doing a VF52 as well, but I don't know if that will get us to the 350 + whp goal, and if it does that turbo wont really be happy at the high boost levels needed for that power output. I don't want to do the turbo twice you know. Too much money, too much wasted time. However, the VF52 is still an option.


Swaybars and tires are the next on the list after tuning.
 
#8 ·
Yeah you won't net near 350 whp with the VF52 on 91. On E85 you'd be close. I would recommend feeling what 300+whp/tq feels like before you decide you want 350whp. Even 300 is a good amount of power. 350 is about the safe limit of the stock block anyways, so you're definitely on the edge of something big going wrong.

If you still insist on 350whp on 91oct for your goals a 20g-xt would suit you well, but you need to run an FMIC with that turbo, or the Process West TMIC with the afternarket turbo adaptor they make.. If you want to keep the stock style TMIC (where the turbo bolts direct to the TMIC), then look at the Blouch 480-xt turbo.
 
#9 ·
As you said, the 350 whp mark for this car is at the limit of what people have agreed is the "safe" zone for this car with it's stock internals/tranny, which is why we are shooting for that target. The reason why we arent shooting for anything lower is because the cars we are used to are all much more powerful. So at around 300 whp the car would still feel mundane. I think going for the cxr the first time around would save a lot of time and money. As far as that turbo itself is concerned, has anyone had any complaints about it, or heard of any? I've done a lot of research on it and I have come up with none. I think in it's price range it's the best unit around, so long as the build quality is not garbage.


As far as the air/fuel ratios go, does anyone have any data logging they can post that shows the ratios without tuning with these or similar mods on this car? I'd be interested to see what they are.
 
#11 ·
I'd be interested as well. I'm guessing it has about 205-215 whp at the moment, even without the tune it's a big improvement over stock.

I'm planning on getting a wideband in a week and an etune within a few weeks. So what I'd like to do is run on a dyno before the tune and then one right after.
 
#14 ·
Yeah, you found the correct parts. But, I'm surprised you didn't read all of the This car needs tuned for each part you install besides a CBE or Turbo Inlet. Even still....350whp is the knife's edge of safety. Especially since that figure depends on which dyno you're using. ::facepalm:: I wouldn't have installed a single part without a protune already scheduled.

And 350whp on 91 oct will take a lot more turbo than what I'm running. Not smaller...expect some lag once you get into the large turbo range. My car has a quick spool and your magic number. Except I run 93 oct.
 
#16 ·
Well, its your car. But, without a boost gauge you can't tell if or how much you're getting into it. I found with my headers that its real easy to get into the boost.
 
#18 ·
Kirt is not saying anything about a cat in either... He is referring to replacing parts... Changing the UP/Header will make your car run bad (you know this)... He is saying just to watch your boost, that's all.
 
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