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Need feedback ASAP

7K views 55 replies 11 participants last post by  dumdum 
#1 ·
Hi All, long story short: I have 05 WRX, 46K miles. Rod is bent and dealer is replacing block and pistons under warranty. Approx two weeks of rental car on my own dime (just complaining)... each day adds up though.

To take advantage of the situation, I am doing upgrades and "early mainentance." Just found this forum. Ordering parts in next day or so.

Proposed "early maintenance" = new timing belt (i.e., only at cost of belt), replace clutch with STI ceramic clutch assembly.

Proposed mods (all STi and Cobb where possible):

STi turbo
up-pipe
downpipe
keeping stock cats* but replacing all other exhaust, turbo back
cold air intake
BOV

*I've been told that stock cats are minimally restrictive. I was told that high-flow cats by comparison are not worth the extra $ in terms of bang for buck.

Me - once all done, Cobb AccessPORT - have friend (currently can't reach him) who can set up/tune.

The above list nearly zero's out my budget.

Anything I'm missing that would be a low-cost no-brainer to add at this point? For example, should I be looking at injection system or fuel pump? Should I replace engine mounts? Should I consider upgraded intake manifold and intercooler in exchange for somethintg on the above list.

Sorry about all the newbie questions. This came up fast and the time window is short!!

Many thanks for ANY feedback!!!!
 
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#34 · (Edited)
You need to do a few things:

1) What STi turbo? you need the exact model number (i.e. VF34, VF39, VF43).
2) You have to get injectors to run an upgraded turbo. To use a stock cobb map (i.e. VF39 Map you need STi Pinks which are 565ccs). Honeslty, I would skip the STi pinks and get some Dershwerks 660cc injectors for more headroom (you will need a custom tune for sure...see #s 3-4)
3) If you carefully read the Cobb map notes it says to use the stock intake or Cobb Intake ONLY. You will need a custom open source tune/or a protune to correctly tune your car with that TurboXS intake. Cobb has certain paramenters for their "general tune" once you start changing stuff/adding parts that are not compatiable with their map you will throw off your AFR (Air to Fuel Ratio).
4) You may want to consider skipping the Cobb AP and go straight for a custom open source tune. Cobb AP is $700, a protune w/AP is $500 so that = $1200. When you can get a custom open source tune with dyno time and road tune for around $500-$600 (my tuner charges $500 for dyno tune with a road tune to finish it off).
 
#36 ·
OK THANK YOU! Much more reading to do. I will not run STI turbo on Cobb Stage II map. I don't know which STi turbo yet; I (wrongly) assumed there was only one STi turbo upgrade reccommended for the 05 WRX wagon. I will find out more; the turbo is the only thing I don't have specs for. More to come...
 
#37 ·
I will not run STI turbo on Cobb Stage II map.
And if you run ANY of the STI turbos you will need larger injectors.At least 565cc.Stock injectors are 420cc.Cobb map notes for the STi turbo maps will clearly state you must run larger injectors and the map is prescaled for 565cc injectors.Any other size injectors will need custom tuning.
 
#41 ·
Update: Saga still in progress - I'm waiting on injectors.

First, feedback from the following tuners (I thought you all would find the information interesting, especially about the TXS intake):

555 Motorsports
CAMTuning.com
awdtuning.com
MPS™ Custom Tuning Services
Elementuning.com

In no particular order:

"you have to go with bigger injectors NOW. The mods on that list will max the injectors out around 10psi or less and you will run dangerously lean as well as cause injector damage. At the very least, you need to get ahold of some STi pinks or blues."

"With the OEM ecu the MAF diameter is critical and a map will be based specifically for a certain intake. Since I was one of the first employees at TXS I know their standard size intake (at least a few years ago) is the same diameter as OEM and there is very little change in AFR due to this intake compared to OEM."

"There isn't a map for your setup. You need to get injectors to support the STi turbo. If you stay with stock injectors you will run out of fuel at fairly low boost, and run the risk of damaging your engine again. If you get yourself some JDM pink injectors you'll be able to run Cobb's OTS VF39 map. What version AP do you have? I can easily email tune your car if you have a version 2. The STi clutch barely fits in your car, and will probably require some grinding."

... and two offers to map over the internet.

In other news... the shop called and said the Grimmspeed uppipe is real perdy, but has the same diameter as the 05WRX stock, and the stock uppipe is also catless (the only reason the new uppipe was reccommended) and has heat shields.

ANY OPINIONS as to whether I should keep stock uppipe versus replacing with Grimmspeed?

On order: Deatschwerks Cobb Spec 650cc Injectors for 2005 WRX "for the extra headroom." :)

Clarification, the new clutch going in is SPt, not STi. Also, folks have been asking about the STi turbo: it's VF39.

More to come... thanks!
 
#42 ·
Update: Saga still in progress - I'm waiting on injectors.

First, feedback from the following tuners (I thought you all would find the information interesting, especially about the TXS intake):

555 Motorsports
CAMTuning.com
awdtuning.com
MPS™ Custom Tuning Services
Elementuning.com

In no particular order:

"you have to go with bigger injectors NOW. The mods on that list will max the injectors out around 10psi or less and you will run dangerously lean as well as cause injector damage. At the very least, you need to get ahold of some STi pinks or blues."

"With the OEM ecu the MAF diameter is critical and a map will be based specifically for a certain intake. Since I was one of the first employees at TXS I know their standard size intake (at least a few years ago) is the same diameter as OEM and there is very little change in AFR due to this intake compared to OEM."

"There isn't a map for your setup. You need to get injectors to support the STi turbo. If you stay with stock injectors you will run out of fuel at fairly low boost, and run the risk of damaging your engine again. If you get yourself some JDM pink injectors you'll be able to run Cobb's OTS VF39 map. What version AP do you have? I can easily email tune your car if you have a version 2. The STi clutch barely fits in your car, and will probably require some grinding."

... and two offers to map over the internet.

In other news... the shop called and said the Grimmspeed uppipe is real perdy, but has the same diameter as the 05WRX stock, and the stock uppipe is also catless (the only reason the new uppipe was reccommended) and has heat shields.

ANY OPINIONS as to whether I should keep stock uppipe versus replacing with Grimmspeed?

On order: Deatschwerks Cobb Spec 650cc Injectors for 2005 WRX "for the extra headroom." :)

Clarification, the new clutch going in is SPt, not STi. Also, folks have been asking about the STi turbo: it's VF39.

More to come... thanks!
Pretty much what we already told you.Don't find the info about the TurboXS intake interesting at all.Thats been known information for at least 5 years now.This Intake FAQ's was created in 2004 and it listed the TurboXS intake as one that did not screw up the MAF signal Intake FAQ: Read if you are thinking of buying one! - NASIOC Trust me,there is little I don't know about these cars (as well as other memebers here) considering I have been running around on 4-5 different Subaru forums for around 5 years now soaking up info:D Hopefully the people installing the parts are better at that than giving technical advise.They sound like complete morons.The stock up-pipe is not catless on a 05 WRX.Sounds like the previuos owner swapped it out for an STI one or gutted the stocker.If its the STI one,use it.If its the gutted stocker,use the Grimmspeed one as it will flow better.
 
#46 · (Edited)
Hi all. I've been unable to post much, but between trips wanted to provide a brief update:

Have car! :D OMG.

Final parts list installed:

Organic STi clutch
STi VF39 turbo
GrimmSpeed Up-pipe w/ Flex Section ceramic coated
Cobb Accessport v 2.0
Invidea hi-flow catted downpipe
Invidea G200 catback system w/ silencer
Cobb SF intake
Cobb Tuning Lightweight Main Pulley
HKS 71004-AF008 HKS SSQV BOV Kit (recirc)
TXS TMIC Kit
Walbro 255 Fuel Pump
Subaru platinum plugs
Deastchwerks 650cc injectors

The map being run is as suggested above for now:
VF39 turbo, STi TMIC, STi "Pink" 565cc injectors & Turboback exhaust using 93 octane

The mechanic checked out the car with all gauges/probes/meters and everything was within parameters using the above map. Nice idle, amazingly fast smooth acceleration, no backfiring or misfiring. AF and temps fine. Taking it moderately easy while driving until I can get a protune. Exhaust smells a bit rich, but no CELs or errors in Cobb datalogger.

The clutch had serious shudder issues first couple of days... now OK, but when decelerating in gear, I hear sandy grinding noise through a small part of the decel range. Having this checked out tomorrow.

More to come... just checking in.

Cheers!
 
#47 ·
What is your AFR?

If you don't know then you may need a wideband 02 to check it out. B/c you are running a Cobb Map outside of its parameters. I realize your mechanic said it was within spec, but you still need know exactly what AFR you are running. You may be within the parameters at idle, but how about at WOT?

The Turbo XS TMIC and Intake and 650cc injectors are all out of spec with the Cobb Map notes. I highly recommend data logging, checking your AFR, and/or getting a protune. A good protune will give you more power and also your car will run better.
 
#51 ·
All, I really do appreciate the patience and continued feedback. It may seem like I don't get it, but I really do... as stated in my earlier sentence: "Taking it moderately easy while driving until I can get a protune. Exhaust smells a bit rich, but no CELs or errors in Cobb datalogger." I am logging. I was monitoring AFR on the Cobb AP and cruising speeds yielded an average of 14.1. At high boost, it dropped below 11... and as I understand it, the AP is not good for reading below this level. No more high boost for me until protune.

I just got off the phone with a pro tuner with TopSpeed in Atlanta. He and his partner come to JAX and TPA to use local 4-wheel dyno. Everyone I ask says these guys are excellent tuners. I am making an appointment. In the mean time, I'll be monitoring my boost to keep it under 6-8 lbs and Long FT, which should be between -5% and +5%... with this and driving easy and I should be OK until the protune. I also don't have any sharp drop-offs in the DA, which is also a good sign.

I look forward to posting some dyno charts. Thanks again. I'll be baaaack.

Thanks again,

MH
 
#52 ·
Hi folks.. another update. The update delay is partly due to my having riod surgery. Dang. I don't wish that on my worst enemy!

I've still been driving the car fairly easy until I get a protune with Topspeed in Atlanta. I'm still getting no ECU error codes on the Cobb.

After the mods, I noticed a loud grinding sound during decel across about a 500 rpm range in 3 and 4th gear. I took the car to local Scoob dealer and they attempted to fix it, again under warranty like the engine. They inspected my 49K mile car, found tranny problems and did an overhaul: new roller bearings, seals, and center diff assembly. While on rack I asked them to take a look at the new perf clutch because it had bad shudder and was burning more than I would think any new clutch should. (Not that I'm an expert!!) It turned out that only about 50% of the clutch plate was making contact, so they rotated it a notch and it now is much better. The plate was not scored at all.

Anyway, after i get the car back, the decel grinding noise is not appreciably better so I do some research and found this article:

Subaru WRX Transmission - Gear Set - Turbo Magazine

See item #5... Hmmmm. Happy new tranny parts.

About the grinding, I also read how tire pressure differential may be a fix ... sounds a bit strange. I have not tried that yet.

Stay tuned for dyno charts in late July.

Cheers, MH
 
#53 ·
Other interesting oddities from Mr. Happy. A couple of weeks ago I removed the silver insert in the HKS SSQV because I'm not a fan of the whistling noise. About a week after that I noticed I was getting a flutter sound from the turbo during blow off. Upon reading many forums, I learned a) turbo flutter not good, and 2) some folks had flutter with this BOV. Also, I recalled a conversation with my soon-to-be tuner - one of the first things he said was something like "we recommend people use the WRX stock BOV - get rid of the HKS."

Gee, where have I heard that before... wait, I'll save you the trouble: :beatentod

So, I replaced the HKS with the original WRX BOV. Turbo flutter is gone. I'm also getting higher boost... 3-5psi on average when I give it about the same amount of throttle. Bad HKS BOV or POS HKS BOV? Regardless, I'm returning it an we'll see what they say.

MH
 
#54 ·
I'm also getting higher boost... 3-5psi on average when I give it about the same amount of throttle. Bad HKS BOV or POS HKS BOV? Regardless, I'm returning it an we'll see what they say.

MH
The HKS one is not one of the better ones but what people don't understand that 95% of all aftermarket BOV are adjustable/tunable.This means they probably are not "ready to go" out of the box and will require initial tuning of the part.If your getting higher boost,that clearly shows it was leaking.Usually the 50/50 BOV's are less temperamental and will act like the stock BPV under light boost (APS).
 
#55 ·
Update and dyno results

I'll start by thanking everyone once again for all your feedback and advice.

I made an appointment at Topspeed in Atlanta and sent a datalog.

Scott Seigel noticed that my long term fuel trim was very low so he sent me a LIMP map to use until my tune. I had already replaced my stock BOV on the car, and at Scott's sugestions, I removed the Cobb SF intake and put the stock air intake back on the car. I get to Atlanta and after the first couple of dyno runs we discover my crunchy new STi performance clutch was slipping. Nice. Thankfully, the shop had one clutch in stock and they made the time to re-strap and tune my car at the end of the day. My STi clutch looked horrible - I'm taking that up with Subaru. The Atlanta shop installed an ACT clutch - I like it MUCH better, and no chatter! Also removed the Invidea exhaust silencer. Scott tuned my car a little aggressive only if I promised to get an STi hood scoop. Anybody got a silver one for sale or trade for a WRX scoop?

2005 WRX

Final parts list:

ACT clutch street disk SB3HDMMN
STi VF39 turbo
GrimmSpeed Up-pipe w/ Flex Section ceramic coated
Cobb Accessport v 2.0
Invidea hi-flow catted downpipe
Invidea G200 catback system
Cobb Tuning Lightweight Main Pulley
TXS TMIC Kit
Walbro 255 Fuel Pump
Deastchwerks 650cc injectors

The car sounds incredible... on the interstate next to concrete construction barriers, it sort of sounds like a P-51 mustang. Very sweet. Enjoying my new rocket! My wife semi-sarcastically says, "Gee honey, now I can here when you come home even when I'm in the back of the house."

For those of you who said things like "new BOV is bad idea" you know how you are... thanks again.

Oh, and... for sale:
HKS SSQV BOV barely used
Cobb SF intake barely used
 

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#56 ·
Very nice numbers!Scott and Topspeed are very well known names in the Subaru community!Glad you got everything worked out.FYI-Most dealership mechanics generally knows less than most die hard enthusiast(unless they are an enthusiast).
 
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