proper operation of BOV

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proper operation of BOV

Unread postby PaulC-turbo5.0 » Mon Aug 31, 2020 9:17 am

Been having issues with rich to lean swings when shifting and its making me wonder if i have my BOV operating properly. I have a turbosmart supersonic BOV vented to atmosphere which has an adjustable cap to set spring tension. Stock cam so 18-20 inches of vacuum at idle. I have always had the spring set pretty soft so the valve dumps on every shift and will even dump on a higher rpm free rev. I have recently started wondering if this is correct and havent found a detailed breakdown on exactly how it "should" function for my application on the web. Even the directions for setting it from TS themselves are extremely basic.

So in my application how exactly should this BOV perform? Or what is the proper way to "tune" the spring tension of a BOV? I have increased spring tension a bit 2 times over the last day and its not dumping as easily but still pretty easy and doesnt seem like its lessened the AFR swings.
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siemens deka 60's, stock lines, in tank 255lph pump
3" PMAS HPX slot
stock T5 with ram clutch, 3.55 gears
67mm On3 ceramic BB turbo, custom 2.5" stainless hotside built by me, custom 3" cold side through On3 intercooler, 10psi
custom 3" downpipe into 2.5" cat back with mac flowpath mufflers

Re: proper operation of BOV

Unread postby decipha » Mon Aug 31, 2020 11:15 am

http://efidynotuning.com/pre.htm#bov

bov should be mounted as close to the turbo as possible well before the IC and the throttle body. MAF should be mounted in the inlet pipe leading to the throttle body.

shouldn't have any reversion going on to affect AFRs
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Re: proper operation of BOV

Unread postby PaulC-turbo5.0 » Mon Aug 31, 2020 12:42 pm

cool thanks for the info. I have posted about this a few different times, youve asked for logs and tune files but doesnt seem you have found time to check them out.

I have it setup correctly and just today adjusted so the spring is on full hard and it still seems to blow off relatively easily, not super easily like previously but still blowing on shifts when not in boost. cant for the life of me figure out why its affecting the afr so much
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Vehicle Information: 1989 Mustang GT Convertible 5.0, GUFX/A9L2, TP RT, Moates Quarterhorse & Jaybird
Stock 302, stock cam, stock E7 heads, felpro 9333pt1 head gaskets and ARP studs, GT40 upper and lower-upper reversed
siemens deka 60's, stock lines, in tank 255lph pump
3" PMAS HPX slot
stock T5 with ram clutch, 3.55 gears
67mm On3 ceramic BB turbo, custom 2.5" stainless hotside built by me, custom 3" cold side through On3 intercooler, 10psi
custom 3" downpipe into 2.5" cat back with mac flowpath mufflers

Re: proper operation of BOV

Unread postby decipha » Mon Aug 31, 2020 4:45 pm

yeah no free time
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91 4r70w - Skarlett
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93 auto - Danika
94 5spd Rionda
95 auto Aisha
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06 Chrysler 300 AWD - Sharifa

Re: proper operation of BOV

Unread postby PaulC-turbo5.0 » Mon Aug 31, 2020 5:28 pm

It’s cool man I’m fairly confident there isn’t anything tune related that’s going to help.

Would you recommend I try shimming the spring? Even in the full hard position it seems like it’s popping off to easily.
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Vehicle Information: 1989 Mustang GT Convertible 5.0, GUFX/A9L2, TP RT, Moates Quarterhorse & Jaybird
Stock 302, stock cam, stock E7 heads, felpro 9333pt1 head gaskets and ARP studs, GT40 upper and lower-upper reversed
siemens deka 60's, stock lines, in tank 255lph pump
3" PMAS HPX slot
stock T5 with ram clutch, 3.55 gears
67mm On3 ceramic BB turbo, custom 2.5" stainless hotside built by me, custom 3" cold side through On3 intercooler, 10psi
custom 3" downpipe into 2.5" cat back with mac flowpath mufflers

Re: proper operation of BOV

Unread postby dleach1407 » Mon Aug 31, 2020 5:56 pm

PaulC-turbo5.0 wrote:cool thanks for the info. I have posted about this a few different times, youve asked for logs and tune files but doesnt seem you have found time to check them out.

I have it setup correctly and just today adjusted so the spring is on full hard and it still seems to blow off relatively easily, not super easily like previously but still blowing on shifts when not in boost. cant for the life of me figure out why its affecting the afr so much


What you are describing seems to be normal operation for a BOV. Mine also "blows off" when not in boost but this is attributed to the turbo spinning and the throttle plate closing causing a backup of pressure. The turbo isnt spinning fast enough to produce pressure when the throttle is open but it is once the plate is closed which is why you get the blow off sound. I dont think there is anything wrong with your BOV but it appears both of us are still dealing with this.
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331 10.2:1 compression, TFS 11r 190 56cc heads
HPX MAF 3.25 OD tube with SaxonPC air straightener
F303 Cam, 1.6 trickflow rockers
T5 with an XTD clutch that somehow holds my power
Returnless upgrade w/10an supply
BBRC offset fuel rails
03 cobra tank w/on3 triple hat, 80lb Dekas
Minor upgraded T5 with counter gear stiffening plate
76mm On3 turbo, HP hotside, Custom coldside
560WHP and 606TQ 8lbs tapering to 6 91 octane
27degrees total timing.
Other Vehicle(s): 1957 Ford F100
Mustang II front suspension -done
C-notched rear frame - done
Luxury ECU using RZASA - have
Fuel injected explorer 302 - have
4r70W -have

Lots of stuff planned including air bags and twin 55mm turbos.

Re: proper operation of BOV

Unread postby PaulC-turbo5.0 » Mon Aug 31, 2020 8:43 pm

Glad to hear yours operates the same. I haven’t second guessed it’s operation until recently while trying to narrow down the afr swings.
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Vehicle Information: 1989 Mustang GT Convertible 5.0, GUFX/A9L2, TP RT, Moates Quarterhorse & Jaybird
Stock 302, stock cam, stock E7 heads, felpro 9333pt1 head gaskets and ARP studs, GT40 upper and lower-upper reversed
siemens deka 60's, stock lines, in tank 255lph pump
3" PMAS HPX slot
stock T5 with ram clutch, 3.55 gears
67mm On3 ceramic BB turbo, custom 2.5" stainless hotside built by me, custom 3" cold side through On3 intercooler, 10psi
custom 3" downpipe into 2.5" cat back with mac flowpath mufflers

Re: proper operation of BOV

Unread postby PaulC-turbo5.0 » Tue Sep 01, 2020 6:33 am

interesting results this morning. by the time i pulled out of the driveway the car was in closed loop, i still got the afr swings on the gauge on shifts but didnt hear the big rush of air blowing off and the hesitation was not noticeable. one shift i got the rpm's up a bit higher, heard the pshhhh and sure enough the car stumbled. easier shifts afterward with no stumbling. this makes me think it is related to the BOV spring stiffness and that i need to somehow add more tension still. its something that should be easy enough to experiment with at least.
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Posts: 161
Joined: Wed Aug 28, 2019 6:01 am
Name: Paul Casey
Vehicle Information: 1989 Mustang GT Convertible 5.0, GUFX/A9L2, TP RT, Moates Quarterhorse & Jaybird
Stock 302, stock cam, stock E7 heads, felpro 9333pt1 head gaskets and ARP studs, GT40 upper and lower-upper reversed
siemens deka 60's, stock lines, in tank 255lph pump
3" PMAS HPX slot
stock T5 with ram clutch, 3.55 gears
67mm On3 ceramic BB turbo, custom 2.5" stainless hotside built by me, custom 3" cold side through On3 intercooler, 10psi
custom 3" downpipe into 2.5" cat back with mac flowpath mufflers

Re: proper operation of BOV

Unread postby dleach1407 » Tue Sep 01, 2020 4:56 pm

Is your maf in a blowthrough or draw-through configuration. The only way that makes sense is if the BOV is after the maf.
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Vehicle Information: 1995 Mustang T5 CBAZA/T4M2 Moates QH BE or TpRT
331 10.2:1 compression, TFS 11r 190 56cc heads
HPX MAF 3.25 OD tube with SaxonPC air straightener
F303 Cam, 1.6 trickflow rockers
T5 with an XTD clutch that somehow holds my power
Returnless upgrade w/10an supply
BBRC offset fuel rails
03 cobra tank w/on3 triple hat, 80lb Dekas
Minor upgraded T5 with counter gear stiffening plate
76mm On3 turbo, HP hotside, Custom coldside
560WHP and 606TQ 8lbs tapering to 6 91 octane
27degrees total timing.
Other Vehicle(s): 1957 Ford F100
Mustang II front suspension -done
C-notched rear frame - done
Luxury ECU using RZASA - have
Fuel injected explorer 302 - have
4r70W -have

Lots of stuff planned including air bags and twin 55mm turbos.

Re: proper operation of BOV

Unread postby PaulC-turbo5.0 » Wed Sep 02, 2020 6:52 am

blow through. my intact tract is for sure setup correctly so yes it doesnt make sense whats going on. if it wasnt for this issue i wouldnt be second guessing a thing
PaulC-turbo5.0
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Posts: 161
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Name: Paul Casey
Vehicle Information: 1989 Mustang GT Convertible 5.0, GUFX/A9L2, TP RT, Moates Quarterhorse & Jaybird
Stock 302, stock cam, stock E7 heads, felpro 9333pt1 head gaskets and ARP studs, GT40 upper and lower-upper reversed
siemens deka 60's, stock lines, in tank 255lph pump
3" PMAS HPX slot
stock T5 with ram clutch, 3.55 gears
67mm On3 ceramic BB turbo, custom 2.5" stainless hotside built by me, custom 3" cold side through On3 intercooler, 10psi
custom 3" downpipe into 2.5" cat back with mac flowpath mufflers

Re: proper operation of BOV

Unread postby decipha » Wed Sep 02, 2020 9:02 am

if its popping off though its building pressure. Even the slightly bit of pressure is going to escape back out so it could cause reversion and skew the maf readings regardless.
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90 (4x 5spds) - Dante, Ruby, Daja, Ava
91 4r70w - Skarlett
92 (2x) 5spd & auto - Bianqa, Andrea
93 auto - Danika
94 5spd Rionda
95 auto Aisha
Other Vehicle(s): Others:
00 Lincoln LS - Luanda
98 Camaro SS - Bounquisha
02 Harley F-150 - Sasasha
03 Marauder - DyShyKy
00 Explorer 5L - Bernyce
07 GMC 2500HD 6L - Veranafer
06 Chrysler 300 AWD - Sharifa

Re: proper operation of BOV

Unread postby PaulC-turbo5.0 » Wed Sep 02, 2020 9:18 am

that does make sense. I am sure i just caught up on this BOV thing in hopes of correcting this issue.

what can be done to help or correct reversion? i guess thats why i am trying to correlate the 2, if the bov stays closed the air cant possibly revert lol.
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Posts: 161
Joined: Wed Aug 28, 2019 6:01 am
Name: Paul Casey
Vehicle Information: 1989 Mustang GT Convertible 5.0, GUFX/A9L2, TP RT, Moates Quarterhorse & Jaybird
Stock 302, stock cam, stock E7 heads, felpro 9333pt1 head gaskets and ARP studs, GT40 upper and lower-upper reversed
siemens deka 60's, stock lines, in tank 255lph pump
3" PMAS HPX slot
stock T5 with ram clutch, 3.55 gears
67mm On3 ceramic BB turbo, custom 2.5" stainless hotside built by me, custom 3" cold side through On3 intercooler, 10psi
custom 3" downpipe into 2.5" cat back with mac flowpath mufflers

Re: proper operation of BOV

Unread postby decipha » Wed Sep 02, 2020 10:12 am

you only want the bov to pop when there is boost in the inlet. If it pops up and you hadn't built any pressure then the spring is too soft.
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decipha
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Location: New Orleans, LA
Name: Michael Decipha Ponto
Vehicle Information: Supercoupin' x10
90 (4x 5spds) - Dante, Ruby, Daja, Ava
91 4r70w - Skarlett
92 (2x) 5spd & auto - Bianqa, Andrea
93 auto - Danika
94 5spd Rionda
95 auto Aisha
Other Vehicle(s): Others:
00 Lincoln LS - Luanda
98 Camaro SS - Bounquisha
02 Harley F-150 - Sasasha
03 Marauder - DyShyKy
00 Explorer 5L - Bernyce
07 GMC 2500HD 6L - Veranafer
06 Chrysler 300 AWD - Sharifa

Re: proper operation of BOV

Unread postby PaulC-turbo5.0 » Wed Sep 02, 2020 11:00 am

well i specifically remember paying attention at one point yesterday and my gauge read 12 inches of vacuum and the valve still popped.

its my 8 year wedding anniversary today so its likely i wont be able to mess with it tonight lol but i want to get the valve off to shim the spring and experiment with it further
PaulC-turbo5.0
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Posts: 161
Joined: Wed Aug 28, 2019 6:01 am
Name: Paul Casey
Vehicle Information: 1989 Mustang GT Convertible 5.0, GUFX/A9L2, TP RT, Moates Quarterhorse & Jaybird
Stock 302, stock cam, stock E7 heads, felpro 9333pt1 head gaskets and ARP studs, GT40 upper and lower-upper reversed
siemens deka 60's, stock lines, in tank 255lph pump
3" PMAS HPX slot
stock T5 with ram clutch, 3.55 gears
67mm On3 ceramic BB turbo, custom 2.5" stainless hotside built by me, custom 3" cold side through On3 intercooler, 10psi
custom 3" downpipe into 2.5" cat back with mac flowpath mufflers

Re: proper operation of BOV

Unread postby dleach1407 » Wed Sep 02, 2020 12:38 pm

Wouldnt the pressure being released cause reversion any time the bov opens due to excess pressure? Seems like the issue would be present every single time you shift in boost.
dleach1407
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Posts: 262
Joined: Fri Sep 07, 2018 10:13 pm
Vehicle Information: 1995 Mustang T5 CBAZA/T4M2 Moates QH BE or TpRT
331 10.2:1 compression, TFS 11r 190 56cc heads
HPX MAF 3.25 OD tube with SaxonPC air straightener
F303 Cam, 1.6 trickflow rockers
T5 with an XTD clutch that somehow holds my power
Returnless upgrade w/10an supply
BBRC offset fuel rails
03 cobra tank w/on3 triple hat, 80lb Dekas
Minor upgraded T5 with counter gear stiffening plate
76mm On3 turbo, HP hotside, Custom coldside
560WHP and 606TQ 8lbs tapering to 6 91 octane
27degrees total timing.
Other Vehicle(s): 1957 Ford F100
Mustang II front suspension -done
C-notched rear frame - done
Luxury ECU using RZASA - have
Fuel injected explorer 302 - have
4r70W -have

Lots of stuff planned including air bags and twin 55mm turbos.

Re: proper operation of BOV

Unread postby PaulC-turbo5.0 » Thu Sep 03, 2020 3:29 pm

just wanted to update this the BOV is not the problem, i have it set back close to where it was originally.

car acted up again this morning and the wideband read rich with just a throttle release, no shifting.
PaulC-turbo5.0
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Posts: 161
Joined: Wed Aug 28, 2019 6:01 am
Name: Paul Casey
Vehicle Information: 1989 Mustang GT Convertible 5.0, GUFX/A9L2, TP RT, Moates Quarterhorse & Jaybird
Stock 302, stock cam, stock E7 heads, felpro 9333pt1 head gaskets and ARP studs, GT40 upper and lower-upper reversed
siemens deka 60's, stock lines, in tank 255lph pump
3" PMAS HPX slot
stock T5 with ram clutch, 3.55 gears
67mm On3 ceramic BB turbo, custom 2.5" stainless hotside built by me, custom 3" cold side through On3 intercooler, 10psi
custom 3" downpipe into 2.5" cat back with mac flowpath mufflers


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