Pretty sure I need a BOV

WolfPlayer · 10-10-2006, 05:39 AM

Yup. I think I might be going 'retro' and becoming a newb

I've been tuning to 20psi on spoolup because there is some testing I want to do. Anyhow, in 4th gear starting out at 2000rpms and going WOT, when she hits 3000rpms I have 20psi on tap with about 50% WGDC (EBCS). Then, almost immediately, pfshhht shht shht .... I lose about 1.5psi, AFRs go lean (recirculation), Turbo Dynamics shoot up, WGDC shoots up to compensate.

My first thought was that I had my turbo dynamics too high in the negative portion. Nope. That is definitely not it.

Egad. The last thing I wanted to do was to buy a new blowoff valve. However, I am toying with the idea of picking up another stock valve and doing the crush mod. Anyone done the crush mod yet?

t

jays05 · 10-10-2006, 05:50 AM

I crushed mine. It worked, but I had some surge issues so I replaced it with a Forge BPV. I get the same surge issues with the Forge and I've come to the conclusion that maybe I am just trying to move too much air. Planning on switching to a Tial bov soon.

I used a c-clamp to crush mine. It crushes really easily so go slow.

Chris05STi · 10-10-2006, 06:14 AM

Call up ImportImage...got mine for $144 shipped for the Forge Recirc BPV...thats 100% recirc.....def worth it!!!

Tbagger · 10-10-2006, 06:44 AM

how bout the APS 50/50??? any good?

WolfPlayer · 10-10-2006, 08:47 AM

Quote:

Originally Posted by Tbagger

how bout the APS 50/50??? any good?

If I had the money I would just buy that and install it. But, I don't. So - I'm probably going to do a little bit of crushing on the stocker.

t

WolfPlayer · 10-12-2006, 05:34 AM

I am beginning to think that it had nothing to do with the BOV. I crushed the stock bov last night (1/8")...

http://www.bescaredracing.com/sti/in...h/DSC06935.JPG

Full pics at ...
http://www.bescaredracing.com/sti/in...v/stock/crush/

I used a MityVac during this process. My stock bov (yes, I know it is a diverter valve but I like typing bov - lol) would start opening at 19in (verified with the MityVac). I crushed it 1/16" and finally to a full 1/8". Now it opens at 20in vacuum.

The problem was still there.

I decided to test the only thing left: Compressor Surge (cavitation). I delayed spoolup by 200rpms and now everything is fine.

One side benefit to doing this crush mod that was unexpected is that the car is just smoother on throttle tip in. It's hard to explain, but I definitely feel it.

t

nxwrxfx · 10-17-2006, 09:45 AM

Well, if your crushed modded one fails then consider getting a JDM STi (Ver. 7) bypass valve. No tuning needed and it'll hold up to 25psi with no problems.

I just got one through an importer, but I haven't installed it yet. It was cheap, and is a direct bolt on!

WolfPlayer · 10-17-2006, 10:56 AM

Quote:

Originally Posted by nxwrxfx

Well, if your crushed modded one fails then consider getting a JDM STi (Ver. 7) bypass valve. No tuning needed and it'll hold up to 25psi with no problems.

I just got one through an importer, but I haven't installed it yet. It was cheap, and is a direct bolt on!

Where did you get it and how much was it?

t

kts262 · 10-17-2006, 11:04 AM

http://www.japanparts.com/db/partsli...ddle=1&small=1

on the 2nd page (their javascript/coding foo won't let me give you a direct link) there is Part# 113-068-14471 - 14471 VALVE ASSY. AIR-BYPASS - $57.29.

Not 100% sure this is it, send a PM to Japanparts on here and they should be able to help. jdmpartstx.com gets them from time to time too and now they are local (jdmpartsmd.com doesn't sound as cool.

)

WolfPlayer · 10-18-2006, 04:25 AM

Thanks Kev!

UPDATE: I feel stupid. I figured out the issue. It was as simple as this: I had ONE boost target too low. Basically, I am trying to spool 20psi @ 3000rpms. I had a boost target at 2600rpms that was too low. As soon as it hit that point, WGDC was pulled away drastically. I raised that point and now all is good. 20psi by 3000rpms easy and holding steadily. Turbo Dynamics clearly showed the issue. I totally overlooked it

t

Christian. · 10-18-2006, 07:56 AM

Quote:

Originally Posted by WolfPlayer

I totally overlooked it

t

Doh! I always log that value when analyzing a tune...you can see when you start to piss of the ECU when the calibration does not make sense with what can happen with the motor's mechanical components. Most calibrations in the ECU rely on the fact that boost is doing what it has been programmed to do. I have watched tuners chase their tail because they are trying to stabilize their fuel or ignition curves yet they refuse to relate that problem to unstable boost.

Christian.

WolfPlayer · 10-18-2006, 08:05 AM

Quote:

Originally Posted by Christian.

Doh! ...

Yea, I kicked myself when I saw it this morning. I decided to work on the boost stuff this morning at 10 pts/sec and so I had to rechoose what I wanted to log. AFR, Turbo Dynamics, Boost, Wastegate, and RPM (I can only do 5 items to get 10 pts/sec). I looked and immediately saw it. Grrrr. At least I saw it.

t

daemon · 10-19-2006, 02:07 PM

I should have picked up on it when you described it. Having had pretty much identical symptoms, though even more pronounced I think, with my SZ55. My surge was so bad if I attempted to fully spool before 4000RPM in fifth gear that my car would go into massive convulsions. I also suspected the BOV at first and did replace mine (to no avail of course). Live and learn.

crystal_Imprezav · 10-29-2006, 07:58 PM

Well looks like it may be time for me to either crush my BPV or get a new BOV. Im cursed by Wolf's posts since everything is eventually happening to me. Heres the situation, I thought I may have had a boost leak which was preventing me from hitting 21~22psi which was my target boost. I finally replaced all my couplers and clamps with silicone ones and t-bolt clamps and what do you know, still can't hit my targets. In 4th+ gears when I go WOT at 2000rpm's I would here a flutter sound thinking it was normal wastegate flutter but now I am thinking otherwise. It only happens at spool and goes away as soon as my boost goes below 20psi. You can see from my log that boost is going up and down and my AFR's are showing it going slightly lean at these points as well leading me to believe that the BPV is not staying shut and releasing pressure back into the intake track. I would have thought that stocker would have been able to hold a little more boost on the stock turbo but guess not. Check it out:

Wolf hows the crush BPV doing? Not sure what I want to do here, either crush it, get a new BOV, or decrease boost and just run more aggressive timing and fuel...

TheMadScientist · 10-30-2006, 01:52 AM

This was the first mod to my Sti.

http://forums.nasioc.com/forums/show...hreadid=454965

TMS

10-10-2006, 05:39 AM	#1
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,645 Join Date: Jun 2004 Trader Rating: (6)	Pretty sure I need a BOV Yup. I think I might be going 'retro' and becoming a newb I've been tuning to 20psi on spoolup because there is some testing I want to do. Anyhow, in 4th gear starting out at 2000rpms and going WOT, when she hits 3000rpms I have 20psi on tap with about 50% WGDC (EBCS). Then, almost immediately, pfshhht shht shht .... I lose about 1.5psi, AFRs go lean (recirculation), Turbo Dynamics shoot up, WGDC shoots up to compensate. My first thought was that I had my turbo dynamics too high in the negative portion. Nope. That is definitely not it. Egad. The last thing I wanted to do was to buy a new blowoff valve. However, I am toying with the idea of picking up another stock valve and doing the crush mod. Anyone done the crush mod yet? t This ad is not endorsed by this member. Please register or login to hide this ad.

10-30-2006, 01:52 AM	#15
TheMadScientist Professional STI Racer Posts: 600 Join Date: Apr 2004 Trader Rating: (0)	This was the first mod to my Sti. http://forums.nasioc.com/forums/show...hreadid=454965 TMS This ad is not endorsed by this member. Please register or login to hide this ad.

10-10-2006, 05:50 AM	#2
jays05 Spec C Club Fav Mod: when it's not blown up Location: Upstate NY Posts: 1,593 Join Date: Nov 2004 Trader Rating: (0)	I crushed mine. It worked, but I had some surge issues so I replaced it with a Forge BPV. I get the same surge issues with the Forge and I've come to the conclusion that maybe I am just trying to move too much air. Planning on switching to a Tial bov soon. I used a c-clamp to crush mine. It crushes really easily so go slow.

10-10-2006, 06:14 AM	#3
Chris05STi I Has a Turbo Timer Car: 2005 Subaru WRX STi Fav Mod: Every single one! Location: NJ Posts: 9,381 Join Date: Jun 2005 Trader Rating: (24)	Call up ImportImage...got mine for $144 shipped for the Forge Recirc BPV...thats 100% recirc.....def worth it!!!

10-10-2006, 06:44 AM	#4
Tbagger Spec C Club Car: 06 STi WRB Location: MASS-HOLE Posts: 1,737 Join Date: Aug 2006 Trader Rating: (1)	how bout the APS 50/50??? any good?

10-12-2006, 05:34 AM	#6
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,645 Join Date: Jun 2004 Trader Rating: (6)	I am beginning to think that it had nothing to do with the BOV. I crushed the stock bov last night (1/8")... http://www.bescaredracing.com/sti/in...h/DSC06935.JPG Full pics at ... http://www.bescaredracing.com/sti/in...v/stock/crush/ I used a MityVac during this process. My stock bov (yes, I know it is a diverter valve but I like typing bov - lol) would start opening at 19in (verified with the MityVac). I crushed it 1/16" and finally to a full 1/8". Now it opens at 20in vacuum. The problem was still there. I decided to test the only thing left: Compressor Surge (cavitation). I delayed spoolup by 200rpms and now everything is fine. One side benefit to doing this crush mod that was unexpected is that the car is just smoother on throttle tip in. It's hard to explain, but I definitely feel it. t

10-17-2006, 09:45 AM	#7
nxwrxfx Lurker Posts: 2 Join Date: Sep 2006 Trader Rating: (0)	Well, if your crushed modded one fails then consider getting a JDM STi (Ver. 7) bypass valve. No tuning needed and it'll hold up to 25psi with no problems. I just got one through an importer, but I haven't installed it yet. It was cheap, and is a direct bolt on!

10-17-2006, 11:04 AM	#9
kts262 HowTo Contributor Car: 2008 DGM (BBS+Navi) Fav Mod: stock FTL? Location: College Park, MD Posts: 2,106 Join Date: Jan 2005 Trader Rating: (8)	http://www.japanparts.com/db/partsli...ddle=1&small=1 on the 2nd page (their javascript/coding foo won't let me give you a direct link) there is Part# 113-068-14471 - 14471 VALVE ASSY. AIR-BYPASS - $57.29. Not 100% sure this is it, send a PM to Japanparts on here and they should be able to help. jdmpartstx.com gets them from time to time too and now they are local (jdmpartsmd.com doesn't sound as cool. )

10-18-2006, 04:25 AM	#10
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,645 Join Date: Jun 2004 Trader Rating: (6)	Thanks Kev! UPDATE: I feel stupid. I figured out the issue. It was as simple as this: I had ONE boost target too low. Basically, I am trying to spool 20psi @ 3000rpms. I had a boost target at 2600rpms that was too low. As soon as it hit that point, WGDC was pulled away drastically. I raised that point and now all is good. 20psi by 3000rpms easy and holding steadily. Turbo Dynamics clearly showed the issue. I totally overlooked it t

10-19-2006, 02:07 PM	#13
daemon Professional STI Racer Car: 2004 STi Location: Florida Posts: 827 Join Date: Feb 2004 Trader Rating: (0)	I should have picked up on it when you described it. Having had pretty much identical symptoms, though even more pronounced I think, with my SZ55. My surge was so bad if I attempted to fully spool before 4000RPM in fifth gear that my car would go into massive convulsions. I also suspected the BOV at first and did replace mine (to no avail of course). Live and learn.

10-29-2006, 07:58 PM	#14
crystal_Imprezav Spec C Club Car: Slow 05 STi Fav Mod: Loping Idle Location: Chewy's Garage Posts: 1,864 Join Date: Mar 2005 Trader Rating: (11)	Well looks like it may be time for me to either crush my BPV or get a new BOV. Im cursed by Wolf's posts since everything is eventually happening to me. Heres the situation, I thought I may have had a boost leak which was preventing me from hitting 21~22psi which was my target boost. I finally replaced all my couplers and clamps with silicone ones and t-bolt clamps and what do you know, still can't hit my targets. In 4th+ gears when I go WOT at 2000rpm's I would here a flutter sound thinking it was normal wastegate flutter but now I am thinking otherwise. It only happens at spool and goes away as soon as my boost goes below 20psi. You can see from my log that boost is going up and down and my AFR's are showing it going slightly lean at these points as well leading me to believe that the BPV is not staying shut and releasing pressure back into the intake track. I would have thought that stocker would have been able to hold a little more boost on the stock turbo but guess not. Check it out: Wolf hows the crush BPV doing? Not sure what I want to do here, either crush it, get a new BOV, or decrease boost and just run more aggressive timing and fuel...