Pretty sure I need a BOV - Page 2

daemon · 10-30-2006, 07:40 AM

Quote:

Originally Posted by crystal_Imprezav

Well looks like it may be time for me to either crush my BPV or get a new BOV.

If you are getting true compressor surge, then neither will help you. I haven't run a VF39 in a while, and never pushed mine that fast when I did, so I don't know really where its limits are, but you do look to be pushing what could be the surge line of the compressor wheel. When that happens boost will start going berserk along with your AFRs, etc.

crystal_Imprezav · 10-30-2006, 02:59 PM

Its not surging, if it was then then my car would buckle and when I let off the throttle it would raise madness. 90% sure its either the BPV limitations or maybe the gasket to the BPV.

daemon · 10-30-2006, 05:05 PM

Quote:

Originally Posted by crystal_Imprezav

Its not surging, if it was then then my car would buckle and when I let off the throttle it would raise madness.

I'm not saying it isn't your BPV, but surging isn't an all buck or nothing proposition. When you are right on the edge you'll get a fluttering that doesn't make the car go nuts. I have walked both sides, and down the line, of compressor surge with my SZ55. I thought it was my BPV to and swapped it for an APS BOV. The problem remained exacty the same. The more I played with tuning, etc., the more it became clear what was actually happening.

My current tune will exhibit the light flutter surge in 5th gear (and a very small amount in 4th) if I floor it around 3500RPM. I didn't tune it out completely (but did get rid of the worst). I just know it is there is if I want to floor it and I'm in 5th below 4000RPM, I downshift.

WolfPlayer · 10-30-2006, 05:33 PM

Definitely look at your Turbo Dynamics as compared to the target boost. That's very similar to what mine looked like and it was as simple as me raising up a target boost point. My target boost at 2600rpms was too low. As the boost went passed 2600 the ECU would get pissed and drop WGDC. This caused the boost to drop, the AFRs to go lean, etc. Definitely log Turbo Dynamics and compare it to your target boost.

t

daemon · 10-30-2006, 05:58 PM

That could most definitely do it too. What is your boost curve like these days Wolf?

WolfPlayer · 10-30-2006, 06:31 PM

Quote:

Originally Posted by daemon

That could most definitely do it too. What is your boost curve like these days Wolf?

20psi at around 2900rpms or so. Holds there for quite some time. 18psi @ 6000rpms. Tapers very quickly to 16psi at redline.

This doesn't show it too well, but this is what I posted in another post on iwsti a few weeks back in relation to what my boost looks like in all the gears when doing a WOT fun.

http://www.bescaredracing.com/sti/st...ost_vs_rpm.JPG

t

SNE2040 · 11-18-2006, 08:23 PM

Eventually after i get my remainding mods and about to protune, i plan on getting a TiAL. My question is, can our cars run TiAL BOV with an AP and a protune without going rich between shifts and also running like crap?

crystal_Imprezav · 11-18-2006, 09:22 PM

If its a recirculating one

SNE2040 · 11-19-2006, 10:40 AM

i dont think tial makes recirculating BOVs

crystal_Imprezav · 11-19-2006, 01:28 PM

Forge motorsports make some pretty good ones price wise compared to tial.

***Majin*** · 11-21-2006, 07:27 AM

i have a GFB Hybrid BPV/BOV. i think it's great - 100% recirc/50% recirc 50% vent/100% vent - you can make it whichever you want. then they have others that will do the same with varying percentages.

boataholic · 11-21-2006, 07:52 AM

Quote:

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.

I just bought one of these. Can't beat it for $57.

thanks for the link.

10-30-2006, 02:59 PM	#17
crystal_Imprezav Spec C Club Car: Slow 05 STi Fav Mod: Loping Idle Location: Chewy's Garage Posts: 1,863 Join Date: Mar 2005 Trader Rating: (11)	Its not surging, if it was then then my car would buckle and when I let off the throttle it would raise madness. 90% sure its either the BPV limitations or maybe the gasket to the BPV.

10-30-2006, 05:33 PM	#19
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,643 Join Date: Jun 2004 Trader Rating: (6)	Definitely look at your Turbo Dynamics as compared to the target boost. That's very similar to what mine looked like and it was as simple as me raising up a target boost point. My target boost at 2600rpms was too low. As the boost went passed 2600 the ECU would get pissed and drop WGDC. This caused the boost to drop, the AFRs to go lean, etc. Definitely log Turbo Dynamics and compare it to your target boost. t

10-30-2006, 05:58 PM	#20
daemon Professional STI Racer Car: 2004 STi Location: Florida Posts: 827 Join Date: Feb 2004 Trader Rating: (0)	That could most definitely do it too. What is your boost curve like these days Wolf?

11-18-2006, 08:23 PM	#22
SNE2040 2 in the Pink, 1 in the.. Car: Slow POS Fav Mod: Slow Car FTL Location: Bergen County, NJ Posts: 623 Join Date: Oct 2004 Trader Rating: (0)	Eventually after i get my remainding mods and about to protune, i plan on getting a TiAL. My question is, can our cars run TiAL BOV with an AP and a protune without going rich between shifts and also running like crap?

11-18-2006, 09:22 PM	#23
crystal_Imprezav Spec C Club Car: Slow 05 STi Fav Mod: Loping Idle Location: Chewy's Garage Posts: 1,863 Join Date: Mar 2005 Trader Rating: (11)	If its a recirculating one

11-19-2006, 10:40 AM	#24
SNE2040 2 in the Pink, 1 in the.. Car: Slow POS Fav Mod: Slow Car FTL Location: Bergen County, NJ Posts: 623 Join Date: Oct 2004 Trader Rating: (0)	i dont think tial makes recirculating BOVs

11-19-2006, 01:28 PM	#25
crystal_Imprezav Spec C Club Car: Slow 05 STi Fav Mod: Loping Idle Location: Chewy's Garage Posts: 1,863 Join Date: Mar 2005 Trader Rating: (11)	Forge motorsports make some pretty good ones price wise compared to tial.

11-21-2006, 07:27 AM	#26
*Majin* A.X.D. Car: 2004 STi Location: LI, NY Posts: 12,790 Join Date: Apr 2004 Trader Rating: (2)	i have a GFB Hybrid BPV/BOV. i think it's great - 100% recirc/50% recirc 50% vent/100% vent - you can make it whichever you want. then they have others that will do the same with varying percentages.