Tuning BOV

TraSTi · 07-18-2007, 08:03 PM

Before I get flamed I need something that hold better than stock since i'm pushing around 24 psi on race gas. I need to know what i have to change to allow the use of a Atmospheric BOV. I have a Worx DS-1 I think that i can switch from full vent to 25/50/75/100 % Atmospheric. There are two sides to tuning this. EM side where I adjust for the extra fuel being Squirted after BLow OFF and then the spring stiffness in the BOV (I has 2 different springs and about 4 setting per springs for a total of 8 different settings.) At first it seemed to soft and you could hear it blow through. Now i think it might be too tight but not sure. Should i set no flutter during part throttle or during WOT? The other thing I though about is having it 100% atmos during street mostly part-throttle (atmos would make it easier to vent so spring would be softer as compared to 100 by pass...) Then for WOT applications like AutoX 100 By pasS?

Anyway I really don't have a clue as to how to tune the BOV. Any tips?

WolfPlayer · 07-19-2007, 05:49 AM

1) You cannot tune for a BPV/BOV. The MAF reads intake airflow. If you blow it off, it is gone. There is no specific compensation in the ECU for the BPV. Since the stock system is recirculating, no extra coding needs to be there. Thus, you cannot tune for it.

2) Set the BOV such that when you are driving part throttle you can snap off the throttle very quickly and you don't get surge. Balance that with holding the pressure that you need at WOT. Basically, set it as soft as you can where the valve still holds while producing some boost.

3) The only solution for a VTA valve is to mount the valve BEFORE the MAF. But, this means that you now have to move the MAF. The best configuration is to put the MAF directly in front of the throttle body and then put the BOV slightly upstream in front of the MAF (far enough away so that it doesn't interfere but as close as possible).

t

TraSTi · 07-19-2007, 07:51 AM

Ok I guess i will have to mantain it circulating... Since its adjustable would 50/50 work or maybe more or les circulation. As stated above i can do 25 and 75 circulation to (and 100 of course...)

TraSTi · 07-19-2007, 07:52 AM

BTW thanks for the tips on tuning BOV stiffness.

WolfPlayer · 07-19-2007, 09:05 AM

I would say to try all the settings and to pick one that gives you the best performance. I like how APS does it. It recirculates 100% until you get into higher boost. In higher boost then it recirculates and VTAs. It's kinda like the best of both worlds.

t

TraSTi · 07-19-2007, 10:38 AM

Yep it seems like a really good design. I don't know if mine works like that since the port for VTA is way up in comparison to the Bypass. Meaning that the piston would have to travel more to open to VTA (more pressure to push it up there...). i will let you know guys but there is a big difference in the way the car behaves depending the setting. At first it actually died in idle with full VTA after a blimp of the throttle (too soft of a spring setting) then it almost died from a blimp with full bypass because the spring setting was to stiff and worked fine with full VTA... Will try some more and update.

pnut2345 · 07-19-2007, 10:41 AM

look into a forge bpv ... all you have to do is change the spring and you be able to run 24 psi!!!!!!!
http://www.forgemotorsport.co.uk/con...2&catalog=1602
http://www.forgemotorsport.co.uk/con...roduct=FMDVTUN

saejosh · 07-19-2007, 05:58 PM

if you are running a frt mount you can get a blow through maf and it will eliminate this prob all togther not to mention it gives a more accurate reading too

TraSTi · 07-19-2007, 07:22 PM

With the Worx BOV (actually i have it set to 100% circulation) it was too stiff but know after changing the stiffness it seems just about right. I will have to see how it work in the autoX.

07-18-2007, 08:03 PM	#1
TraSTi Professional STI Racer Posts: 830 Join Date: Apr 2006 Trader Rating: (2)	Tuning BOV Before I get flamed I need something that hold better than stock since i'm pushing around 24 psi on race gas. I need to know what i have to change to allow the use of a Atmospheric BOV. I have a Worx DS-1 I think that i can switch from full vent to 25/50/75/100 % Atmospheric. There are two sides to tuning this. EM side where I adjust for the extra fuel being Squirted after BLow OFF and then the spring stiffness in the BOV (I has 2 different springs and about 4 setting per springs for a total of 8 different settings.) At first it seemed to soft and you could hear it blow through. Now i think it might be too tight but not sure. Should i set no flutter during part throttle or during WOT? The other thing I though about is having it 100% atmos during street mostly part-throttle (atmos would make it easier to vent so spring would be softer as compared to 100 by pass...) Then for WOT applications like AutoX 100 By pasS? Anyway I really don't have a clue as to how to tune the BOV. Any tips? This ad is not endorsed by this member. Please register or login to hide this ad.

07-19-2007, 05:49 AM	#2
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,695 Join Date: Jun 2004 Trader Rating: (6)	Re: Tuning BOV 1) You cannot tune for a BPV/BOV. The MAF reads intake airflow. If you blow it off, it is gone. There is no specific compensation in the ECU for the BPV. Since the stock system is recirculating, no extra coding needs to be there. Thus, you cannot tune for it. 2) Set the BOV such that when you are driving part throttle you can snap off the throttle very quickly and you don't get surge. Balance that with holding the pressure that you need at WOT. Basically, set it as soft as you can where the valve still holds while producing some boost. 3) The only solution for a VTA valve is to mount the valve BEFORE the MAF. But, this means that you now have to move the MAF. The best configuration is to put the MAF directly in front of the throttle body and then put the BOV slightly upstream in front of the MAF (far enough away so that it doesn't interfere but as close as possible). t

07-19-2007, 07:51 AM	#3
TraSTi Professional STI Racer Posts: 830 Join Date: Apr 2006 Trader Rating: (2)	Re: Tuning BOV Ok I guess i will have to mantain it circulating... Since its adjustable would 50/50 work or maybe more or les circulation. As stated above i can do 25 and 75 circulation to (and 100 of course...)

07-19-2007, 07:52 AM	#4
TraSTi Professional STI Racer Posts: 830 Join Date: Apr 2006 Trader Rating: (2)	Re: Tuning BOV BTW thanks for the tips on tuning BOV stiffness.

07-19-2007, 09:05 AM	#5
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,695 Join Date: Jun 2004 Trader Rating: (6)	Re: Tuning BOV I would say to try all the settings and to pick one that gives you the best performance. I like how APS does it. It recirculates 100% until you get into higher boost. In higher boost then it recirculates and VTAs. It's kinda like the best of both worlds. t

07-19-2007, 10:38 AM	#6
TraSTi Professional STI Racer Posts: 830 Join Date: Apr 2006 Trader Rating: (2)	Re: Tuning BOV Yep it seems like a really good design. I don't know if mine works like that since the port for VTA is way up in comparison to the Bypass. Meaning that the piston would have to travel more to open to VTA (more pressure to push it up there...). i will let you know guys but there is a big difference in the way the car behaves depending the setting. At first it actually died in idle with full VTA after a blimp of the throttle (too soft of a spring setting) then it almost died from a blimp with full bypass because the spring setting was to stiff and worked fine with full VTA... Will try some more and update.

07-19-2007, 10:41 AM	#7
pnut2345 Junior STI Driver Car: 04 subaru wrx sti Location: tampa Posts: 51 Join Date: May 2007 Trader Rating: (1)	Re: Tuning BOV look into a forge bpv ... all you have to do is change the spring and you be able to run 24 psi!!!!!!! http://www.forgemotorsport.co.uk/con...2&catalog=1602 http://www.forgemotorsport.co.uk/con...roduct=FMDVTUN Last edited by pnut2345 : 07-19-2007 at 10:46 AM.

07-19-2007, 05:58 PM	#8
saejosh Junior STI Driver Car: 05 subaru WRX Fav Mod: Txs turbo back Location: wichita Posts: 51 Join Date: Jun 2007 Trader Rating: (0)	Re: Tuning BOV if you are running a frt mount you can get a blow through maf and it will eliminate this prob all togther not to mention it gives a more accurate reading too

07-19-2007, 07:22 PM	#9
TraSTi Professional STI Racer Posts: 830 Join Date: Apr 2006 Trader Rating: (2)	Re: Tuning BOV With the Worx BOV (actually i have it set to 100% circulation) it was too stiff but know after changing the stiffness it seems just about right. I will have to see how it work in the autoX. This ad is not endorsed by this member. Please register or login to hide this ad.