Welcome to the North American Subaru Impreza Owners Club Saturday January 18, 2020
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 07-26-2016, 10:04 AM   #426
Ghia Nut
Scooby Newbie
 
Member#: 201302
Join Date: Jan 2009
Chapter/Region: South East
Location: Birmingham
Vehicle:
2005 WRX Wagon
Aspen White

Default Meh???

Just thought I would chime in. As wrx and sti s become more affordable in age I think it's good nasioc is here as an archive for decent information and occasional phallus measuring.

I did the mod yesterday. It wasn't .16c but it was still cheap. Think total was around 12-15$. Went with m6x1x8mm set screw. I don't think I even needed to drill out the hole to tap it honestly but did just to be safe. Hole the set screw goes into is pretty deep. I will say that I didn't completely tap it to depth. This allowed me to jam the set screw in there as the thread tapered to uncut threads. This kinda provided a seating action as well as a way to lock it in place. I added some dealing paste that's rated to 400 just for peace of mind.

Honestly it took me 10 min to do this mod, another two hours to reinstall the damn tube for recirculation.

Driving impressions. Meh.... I think response did improve but I'm stage 2 and figuring out how to adjust wg arm to get to target boost. Did not feel any chatter or surge from compressor. No chichchichchich as my max boost is now around 14.25 psi . Should be 16.7 ish. I'd say its a worthy mod due to cost. I will say my bpv was full of clean oil which is weird. Any who just thought I would chime in.

Rest in peace MadScientist. Thanks for a post in trying to help the community who loves cars.
* Registered users of the site do not see these ads.
Ghia Nut is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 07-26-2016, 01:28 PM   #427
mrsaturn7085
Scooby Specialist
 
Member#: 375462
Join Date: Dec 2013
Chapter/Region: NWIC
Location: Portland, OR
Vehicle:
2006 Impreza WRX STI
WR Blue

Default

Quote:
Originally Posted by Ghia Nut View Post
Driving impressions. Meh.... I think response did improve...
The purpose of this mod is to increase the level of peak boost you can run. I am not sure which BPV you started with, but at 14.25-16.7 PSI, you do not need this mod, at all. At low boost levels, the amount of chatter you will hear is going to be low, as well.

The stronger spring model (E-marked BPV) is the part that increases response. If you started with this, you wouldn't notice a difference in response, at all.
mrsaturn7085 is offline   Reply With Quote
Old 03-17-2017, 10:48 PM   #428
JMlegacy
Scooby Specialist
 
Member#: 341649
Join Date: Dec 2012
Chapter/Region: International
Location: Sun City
Default

Did this mod, car made beyond 21 psi boost easily. When I let off at partial boost (12-15 psi) I hear the chirp. I don't want to lose a turbo so i reverted the mod by moving the screw to the top, and testing to make sure air is passing the screw on the inside. Drives car, car works like before. Nice mod for a cheap race tune.
JMlegacy is offline   Reply With Quote
Old 03-17-2017, 11:59 PM   #429
mrsaturn7085
Scooby Specialist
 
Member#: 375462
Join Date: Dec 2013
Chapter/Region: NWIC
Location: Portland, OR
Vehicle:
2006 Impreza WRX STI
WR Blue

Default

I think the bypass is around 24 psi, so you shouldn't notice a difference until then. Obviously, this makes more sense on an EJ207 than it does trying to push a VF39 or similar this far.
mrsaturn7085 is offline   Reply With Quote
Old 03-19-2017, 12:28 AM   #430
binny
Scooby Newbie
 
Member#: 198108
Join Date: Dec 2008
Location: Australia
Vehicle:
MY98 WRX
Blue

Default

Quote:
Originally Posted by mrsaturn7085 View Post
More air bypassed means less air entering the cylinders...

So given a specific throttle position (let's say 50%) you've got less wheel torque, right? Weaker intake charge = decreased torque output. I really shouldn't need to elaborate on this part...

The natural response to this is probably going to be 'just add more throttle'. Now you end up with a peaky throttle that feels weak until you hit 80-100% throttle. This is not due to a slow-spooling turbo, but rather the fact that you are dumping/diverting a perfectly usable part-throttle mass of air AWAY from the cylinders.

The next follow-up may be 'but wait, I've got a DBW throttle and can tune it accordingly'. Okay, that's a good band-aid, but you'll be losing throttle resolution by trying to chase a smooth throttle-torque curve. Dedicating the last 50-60% of pedal position to the upper 10-20% of throttle position would just be silly. Due to the nature of the system, this doesn't work anyhow - you can't 'tune out' a mechanically weaker spring at a part-throttle position; it just does not work.

Or, you know, you could just use a BPV that bypasses less air at a part-throttle position. Something like an E-marked, or modified E-marked OEM valve...

Wouldn't the spring pressure be holding the BPV closed during partial throttle scenarios? (Up to the combined spring pressure and manifold pressure)
binny is offline   Reply With Quote
Old 03-19-2017, 12:47 AM   #431
dryvby
Scooby Newbie
 
Member#: 49931
Join Date: Dec 2003
Chapter/Region: MWSOC
Location: Grand Rapids, MI
Vehicle:
0305 wrx/Xt
black/black

Default

18 pages of wrong.
dryvby is offline   Reply With Quote
Old 03-19-2017, 02:14 AM   #432
mrsaturn7085
Scooby Specialist
 
Member#: 375462
Join Date: Dec 2013
Chapter/Region: NWIC
Location: Portland, OR
Vehicle:
2006 Impreza WRX STI
WR Blue

Default

Quote:
Originally Posted by dryvby View Post
18 pages of wrong.
You must be new here.
mrsaturn7085 is offline   Reply With Quote
Old 03-22-2017, 05:35 AM   #433
Master467
Scooby Newbie
 
Member#: 459849
Join Date: Dec 2016
Chapter/Region: MWSOC
Vehicle:
2002 Legacy GT
89N (titanium pearl)

Default

Quote:
Originally Posted by mrsaturn7085 View Post
You must be new here.
Member#: 49931
Join Date: Dec 2003

Not new, maybe he has stock in aftermarket BOV companies?
Master467 is offline   Reply With Quote
Old 03-22-2017, 11:26 AM   #434
andyfloyd
Scooby Newbie
 
Member#: 87587
Join Date: May 2005
Vehicle:
2002 wrx
silver

Default

Quote:
Originally Posted by Ghia Nut View Post
Just thought I would chime in. As wrx and sti s become more affordable in age I think it's good nasioc is here as an archive for decent information and occasional phallus measuring.

I did the mod yesterday. It wasn't .16c but it was still cheap. Think total was around 12-15$. Went with m6x1x8mm set screw. I don't think I even needed to drill out the hole to tap it honestly but did just to be safe. Hole the set screw goes into is pretty deep. I will say that I didn't completely tap it to depth. This allowed me to jam the set screw in there as the thread tapered to uncut threads. This kinda provided a seating action as well as a way to lock it in place. I added some dealing paste that's rated to 400 just for peace of mind.

Honestly it took me 10 min to do this mod, another two hours to reinstall the damn tube for recirculation.

Driving impressions. Meh.... I think response did improve but I'm stage 2 and figuring out how to adjust wg arm to get to target boost. Did not feel any chatter or surge from compressor. No chichchichchich as my max boost is now around 14.25 psi . Should be 16.7 ish. I'd say its a worthy mod due to cost. I will say my bpv was full of clean oil which is weird. Any who just thought I would chime in.

Rest in peace MadScientist. Thanks for a post in trying to help the community who loves cars.
To adjust the wg rod on a td04 you need to tighten the nut on the rod making it shorter and this will delay the opening of the wg as the can will have to overcome more force. Hope this helps.
andyfloyd is offline   Reply With Quote
Old 03-22-2017, 11:28 AM   #435
andyfloyd
Scooby Newbie
 
Member#: 87587
Join Date: May 2005
Vehicle:
2002 wrx
silver

Default

Quote:
Originally Posted by Master467 View Post
Member#: 49931
Join Date: Dec 2003

Not new, maybe he has stock in aftermarket BOV companies?
yes, he must be the one who sells all the knockoff bov's on ebay that work about as well as putting a turkey call in place of the stock BPV. CAWWWWWWWWWWW
andyfloyd is offline   Reply With Quote
Old 03-22-2017, 05:00 PM   #436
4eat05
Scooby Newbie
 
Member#: 378421
Join Date: Jan 2014
Location: NC
Vehicle:
2005 Cobb Stg2+ Wrx
Platinum Silver

Default

ok, so, I have two oem bypass valves in front of me, and I am finally going to do this mod to one of them, but not sure which one....

I have a newer stiffer spring "E marked" usdm valve off an Sti, and an older softer spring pre-E marked usdm valve from my blobeye Wrx.

which of these would you guys do this mod to?
stiffer spring and this mod?
or softer spring and this mod?

I kind of want to do it to the stiffer spring valve for faster closing response (and it looks better than my old softer spring valve lol) but kind of worry it might be "too stiff",but idk.

which valve would you guys do this mod to? stiffer spring or softer spring oem bypass valve? thanks everyone!
4eat05 is offline   Reply With Quote
Old 03-22-2017, 11:35 PM   #437
mrsaturn7085
Scooby Specialist
 
Member#: 375462
Join Date: Dec 2013
Chapter/Region: NWIC
Location: Portland, OR
Vehicle:
2006 Impreza WRX STI
WR Blue

Default

Modify the E-marked valve.
mrsaturn7085 is offline   Reply With Quote
Old 03-22-2017, 11:36 PM   #438
mrsaturn7085
Scooby Specialist
 
Member#: 375462
Join Date: Dec 2013
Chapter/Region: NWIC
Location: Portland, OR
Vehicle:
2006 Impreza WRX STI
WR Blue

Default

Quote:
Originally Posted by Master467 View Post
Member#: 49931
Join Date: Dec 2003

Not new, maybe he has stock in aftermarket BOV companies?
340 posts, and most are total garbage.
mrsaturn7085 is offline   Reply With Quote
Old 03-26-2017, 06:19 PM   #439
4eat05
Scooby Newbie
 
Member#: 378421
Join Date: Jan 2014
Location: NC
Vehicle:
2005 Cobb Stg2+ Wrx
Platinum Silver

Default

Did the $0.16 mod to my newly aquired e-marked sti bypass valve and it flutters too much at low boost, so now I'm going to try it on my stock wrx pre-e-marked bypass valve and see how that goes.

Modded e-marked sti bypass valve will most likely be for sale soon so PM me if you want it. Both holes drilled with #7 and tapped with 1/4-20 tap and plugged with 1/4-20 allen head set screw. Now it can be run either way (stock or $0.16 modded/jdm type) by simply moving the set screw from one hole to the other.

Last edited by 4eat05; 03-26-2017 at 11:42 PM.
4eat05 is offline   Reply With Quote
Old 04-03-2017, 01:33 PM   #440
amalgrover
Scooby Specialist
 
Member#: 183480
Join Date: Jun 2008
Chapter/Region: South East
Default

Quote:
Originally Posted by 4eat05 View Post
Did the $0.16 mod to my newly aquired e-marked sti bypass valve and it flutters too much at low boost, so now I'm going to try it on my stock wrx pre-e-marked bypass valve and see how that goes.

Modded e-marked sti bypass valve will most likely be for sale soon so PM me if you want it. Both holes drilled with #7 and tapped with 1/4-20 tap and plugged with 1/4-20 allen head set screw. Now it can be run either way (stock or $0.16 modded/jdm type) by simply moving the set screw from one hole to the other.
Off throttle flutter is not going to hurt anything...Feel free to mod the other one, but you honestly are just doing recreational maintenance at this point.
amalgrover is offline   Reply With Quote
Old 04-23-2017, 10:55 PM   #441
dryvby
Scooby Newbie
 
Member#: 49931
Join Date: Dec 2003
Chapter/Region: MWSOC
Location: Grand Rapids, MI
Vehicle:
0305 wrx/Xt
black/black

Default

Quote:
Originally Posted by mrsaturn7085 View Post
340 posts, and most are total garbage.
Well done. While I appreciate the time you spent on this, I'm afraid you're assessment is incorrect. Don't hesitate to contact me if you're still struggling with your bov.
dryvby is offline   Reply With Quote
Old 04-24-2017, 01:30 AM   #442
mrsaturn7085
Scooby Specialist
 
Member#: 375462
Join Date: Dec 2013
Chapter/Region: NWIC
Location: Portland, OR
Vehicle:
2006 Impreza WRX STI
WR Blue

Default

Okay, I'll bite - you're more than welcome to contribute. So far you've given us nothing credible or even useful.
mrsaturn7085 is offline   Reply With Quote
Old 04-25-2017, 11:05 PM   #443
dryvby
Scooby Newbie
 
Member#: 49931
Join Date: Dec 2003
Chapter/Region: MWSOC
Location: Grand Rapids, MI
Vehicle:
0305 wrx/Xt
black/black

Default

My intention wasn't to bait anyone, mrsaturn, although after re-reading my post and the responses it was interpreted that way.
Please, what performance issue(s) are you experiencing with your valve?
dryvby is offline   Reply With Quote
Old 04-25-2017, 11:21 PM   #444
mrsaturn7085
Scooby Specialist
 
Member#: 375462
Join Date: Dec 2013
Chapter/Region: NWIC
Location: Portland, OR
Vehicle:
2006 Impreza WRX STI
WR Blue

Default

This thread isn't about issues with the BPV. This thread is about disabling the overboost protection built into late E-marked Subaru BPV assemblies to achieve a higher peak boost pressure before having to upgrade to an aftermarket BOV/BPV.

Essentially, this thread is explaining the Subaru version of what Tomei outlines here for Nissan:

mrsaturn7085 is offline   Reply With Quote
Old 12-07-2019, 05:49 PM   #445
Gerald81
Scooby Newbie
 
Member#: 34226
Join Date: Mar 2003
Default

Tried this mod today as we found my car was leaking boost with the stock BPV at around 22-24 PSI.

However, am I'm not sure if this is due to the mod or other issues with the car, but the tuner was observing a phenomenon whereby he had very little control over the boost. At 87% WGDC, the boost was 14.5 PSI. Increasing WGDC by 1% to 88% would see boost swing to 28 PSI, whereas ideally the target was 25 PSI. However boost would then taper off to 20 PSI at the upper RPM range.

Again, not sure if this is caused by the $0.16 mod, but it certainly helped in the sense the car was not able to go beyond 22-24 PSI previously due to leakage from the unmodified stock BPV.

I wonder if it could be any other issues. Could an actuator rod that is adjusted to be too short cause this?
Gerald81 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 07:11 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2020 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.