bov on a s/c?
02-20-2007, 02:37 AM
#1
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Thread Starter
Join Date: Jan 2007
Location: Austin, TX
Posts: 16
bov on a s/c?
I was looking into putting a bosch 110 on my s/c tc since I heard the stock 102 leaks some, but then I realized that since I'm buying a new part I could get a blow off instead. I've always loved the sound of a bov, and if I can get one on my s/c without any problems then that would be pretty cool.
I didn't know sc's could run bov's until pretty recently so could you guys please enlighten me on the ups and downs of putting a bov on a sc?
Could I use this one below with no problems?
http://dezod.com/pd_vortech_maxflow.cfm
Thanks for the help!
I didn't know sc's could run bov's until pretty recently so could you guys please enlighten me on the ups and downs of putting a bov on a sc?
Could I use this one below with no problems?
http://dezod.com/pd_vortech_maxflow.cfm
Thanks for the help!
02-20-2007, 07:49 AM
#3
Junior Member
Join Date: Dec 2006
Location: Arlington, Texas
Posts: 8
I have a HKS SSQBOV on my supercharger and it is sweet man. It does what its supposed to do as a by pass also. I wish i had a camera i would show you but i don't. But to answer your question yes. http://www.optionimports.com/hksbloffvaun.html. thats a link to a univeral hks ssqbov and if you scroll down on that page it has HKS SSQV BOV Recirculation Fitting and Aluminum Install Flange for HKS SSQV - 1" Hose Adapter. that would be perfect man. And i think those are pretty good prices too. hope that helps.
02-21-2007, 03:47 AM
#10
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Scion Evolution
Join Date: Apr 2005
Location: Woodbridge, VA
Posts: 1,109
https://www.scionlife.com/forums/viewtopic.php?t=162287 same applies to superchargers. Recirc is most recommended for our cars. A hybrid BOV by Go Fast Bits or TurboSmart is a compromise between sound and driveability (reduces chances of stuttering/stalling between shifts that can happen with full atmospheric BOV). The sound won't be as loud as the turbo guys.
02-21-2007, 08:02 AM
#13
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Join Date: Dec 2006
Location: Arlington, Texas
Posts: 8
I have not stalled or it feeling like it would want to stall. You can also ask Jeremy garage1217. I bought my supercharger from him. I am telling you the HKS works like a charm. like the other guy said it wont be as loud as a turbo but people can still hear it going off. Your rpm would have to be around three thousand when you shift into another gear to hear it. You'll learn when to shift to hear the bov. i wish i had a camera to get you guys some clips.
02-21-2007, 10:19 AM
#14
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Join Date: Jan 2007
Posts: 146
Originally Posted by 05trdtc
I have not stalled or it feeling like it would want to stall. You can also ask Jeremy garage1217. I bought my supercharger from him. I am telling you the HKS works like a charm. like the other guy said it wont be as loud as a turbo but people can still hear it going off. Your rpm would have to be around three thousand when you shift into another gear to hear it. You'll learn when to shift to hear the bov. i wish i had a camera to get you guys some clips.
02-21-2007, 05:52 PM
#17
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Join Date: Jan 2006
Posts: 960
Read the following link. It applies to the tC because the Evo is also MAF-based.
http://forums.evolutionm.net/showthread.php?t=209640
http://forums.evolutionm.net/showthread.php?t=209640
ATMOSPHERIC vs. RECIRCULATING vs. 50/50:
The BIG question.
The simple answer:
What kind of valve is your engine management system designed for and/or capable of allowing for the use of?
Yes, I answered a question with another question, but the real answer is, there is no simple answer. Each person will need to consider what their plans for their car are, what type of engine management system they will ultimately be using, and what valve can or can't be used with that type of system. “Blow-off valve sound” aside.
Firstly, we need to know what type of engine management can use what type of valve.
Mass AirFlow systems are designed as "closed-loop" systems requiring the use of a recirculating valve.
Speed Density systems are typically setup as closed-loop systems from the factory, but they can typically use either a recirculating OR atmospheric valve without any major detriment to the system.
MAP based systems (manifold absolute pressure) are typically capable of allowing for the use of either valve as well, but most MAP-based systems are fully stand-alone and require significant tuning to overcome any changes.
Now, with that said, the OEM ECU used on the Evo is a Mass Airflow system. It requires the use of a recirculating valve. If anyone, through the course of modifying their car, plans to continue to use the OEM ECU as the base for their engine management (even if some aftermarket tuner has uploaded new programming or a piggyback system is used), it is HIGHLY recommended to continue to use a recirculating valve.
The use of an atmospheric valve will cause a rich fuel mixture due to the loss of already metered air which the ECU is expecting to remain in the system. When the air is vented, the ECU dumps fuel into the system expecting the air to be there, and it's not. This rich fuel condition can sometimes be severe enough that the ECU cannot compensate for the condition and the car will run rough, not idle properly, experience a loss of power, and also experience poor fuel economy.
I have personally seen, on my own vehicle, a loss of as much as roughly 40 miles per full tank of fuel from using an atmospheric valve on a tuned, but otherwise stock engine management system.
If anyone, through the course of modifying their car, plans to switch their engine management from the OEM ECU to some form of standalone engine management (NOT a piggyback system, as even a piggyback still uses the OEM ECU), they can then, and only then, consider the use of an atmospheric valve, as such a system can compensate for, or be tuned to allow for the use of such a valve without any of the problems mentioned above.
50/50 valves, while seemingly great, are not an ideal solution by any measure, in my personal opinion.
(Yes, everything below is a personal opinion and subject to argument, but I’d like to think I know what I’m talking about.)
While they are designed to accomodate those with the desire for an increase in the "blow-off valve sound" from their car, they do so in a way that is still venting metered air, still causing a somewhat richer fuel condition, and still potentially leading to the above mentioned problems. While they may appear to work on any given vehicle, they are only doing so within a window that is not yet necessarily a largely detrimental problem to the OEM ECU at that time and it's ability to alow for the venting of metered air.
The difficulty lies in that there is no precise way to measure, at least cost effectively for aftermarket companies anyway, the PRECISE amount of air that can "safely" be vented out of the system and not cause a problem for the ECU, in whatever it's current state of tune may be, and it's ability to correctly add fuel to the system in the appropriate ratio. There are innumerable factors to consider that will never be perfectly "tuned" in a single 50/50 valve design to suit all applications.
50/50 valves are essentially trying to "trick" the ECU into believing that enough air is still being recirculated to maintain a proper air/fuel ratio under any given load condition, when, in fact, there is no way to effectively know what ratio should be used, if any at all.
The safe bet is to just use a recirulating valve where recommended and enjoy the security that you know that your ECU is not struggling to maintain a proper air/fuel ratio.
If the added sound is REALLY the most important thing to you, however, you must be willing to accept a level of risk that some problems MAY occur.
While it may be nice to have that blow-off valve (whooshing) sound, I personally feel that it's significantly more important to have a valve that will perform and operate properly for the given application regadless of the amount of noise it makes. I do not feel that valves should be designed to make a particular sound, nor to trick their engine management system, whether factory or aftermarket, into thinking the car is operating properly. Valves are meant to perform a specific function that should be done in a manner best suiting the specific application.
The BIG question.
The simple answer:
What kind of valve is your engine management system designed for and/or capable of allowing for the use of?
Yes, I answered a question with another question, but the real answer is, there is no simple answer. Each person will need to consider what their plans for their car are, what type of engine management system they will ultimately be using, and what valve can or can't be used with that type of system. “Blow-off valve sound” aside.
Firstly, we need to know what type of engine management can use what type of valve.
Mass AirFlow systems are designed as "closed-loop" systems requiring the use of a recirculating valve.
Speed Density systems are typically setup as closed-loop systems from the factory, but they can typically use either a recirculating OR atmospheric valve without any major detriment to the system.
MAP based systems (manifold absolute pressure) are typically capable of allowing for the use of either valve as well, but most MAP-based systems are fully stand-alone and require significant tuning to overcome any changes.
Now, with that said, the OEM ECU used on the Evo is a Mass Airflow system. It requires the use of a recirculating valve. If anyone, through the course of modifying their car, plans to continue to use the OEM ECU as the base for their engine management (even if some aftermarket tuner has uploaded new programming or a piggyback system is used), it is HIGHLY recommended to continue to use a recirculating valve.
The use of an atmospheric valve will cause a rich fuel mixture due to the loss of already metered air which the ECU is expecting to remain in the system. When the air is vented, the ECU dumps fuel into the system expecting the air to be there, and it's not. This rich fuel condition can sometimes be severe enough that the ECU cannot compensate for the condition and the car will run rough, not idle properly, experience a loss of power, and also experience poor fuel economy.
I have personally seen, on my own vehicle, a loss of as much as roughly 40 miles per full tank of fuel from using an atmospheric valve on a tuned, but otherwise stock engine management system.
If anyone, through the course of modifying their car, plans to switch their engine management from the OEM ECU to some form of standalone engine management (NOT a piggyback system, as even a piggyback still uses the OEM ECU), they can then, and only then, consider the use of an atmospheric valve, as such a system can compensate for, or be tuned to allow for the use of such a valve without any of the problems mentioned above.
50/50 valves, while seemingly great, are not an ideal solution by any measure, in my personal opinion.
(Yes, everything below is a personal opinion and subject to argument, but I’d like to think I know what I’m talking about.)
While they are designed to accomodate those with the desire for an increase in the "blow-off valve sound" from their car, they do so in a way that is still venting metered air, still causing a somewhat richer fuel condition, and still potentially leading to the above mentioned problems. While they may appear to work on any given vehicle, they are only doing so within a window that is not yet necessarily a largely detrimental problem to the OEM ECU at that time and it's ability to alow for the venting of metered air.
The difficulty lies in that there is no precise way to measure, at least cost effectively for aftermarket companies anyway, the PRECISE amount of air that can "safely" be vented out of the system and not cause a problem for the ECU, in whatever it's current state of tune may be, and it's ability to correctly add fuel to the system in the appropriate ratio. There are innumerable factors to consider that will never be perfectly "tuned" in a single 50/50 valve design to suit all applications.
50/50 valves are essentially trying to "trick" the ECU into believing that enough air is still being recirculated to maintain a proper air/fuel ratio under any given load condition, when, in fact, there is no way to effectively know what ratio should be used, if any at all.
The safe bet is to just use a recirulating valve where recommended and enjoy the security that you know that your ECU is not struggling to maintain a proper air/fuel ratio.
If the added sound is REALLY the most important thing to you, however, you must be willing to accept a level of risk that some problems MAY occur.
While it may be nice to have that blow-off valve (whooshing) sound, I personally feel that it's significantly more important to have a valve that will perform and operate properly for the given application regadless of the amount of noise it makes. I do not feel that valves should be designed to make a particular sound, nor to trick their engine management system, whether factory or aftermarket, into thinking the car is operating properly. Valves are meant to perform a specific function that should be done in a manner best suiting the specific application.
02-21-2007, 06:05 PM
#18
Junior Member
Thread Starter
Join Date: Jan 2007
Location: Austin, TX
Posts: 16
Originally Posted by mattvs
Read the following link. It applies to the tC because the Evo is also MAF-based.
http://forums.evolutionm.net/showthread.php?t=209640
http://forums.evolutionm.net/showthread.php?t=209640
ATMOSPHERIC vs. RECIRCULATING vs. 50/50:
The BIG question.
The simple answer:
What kind of valve is your engine management system designed for and/or capable of allowing for the use of?
Yes, I answered a question with another question, but the real answer is, there is no simple answer. Each person will need to consider what their plans for their car are, what type of engine management system they will ultimately be using, and what valve can or can't be used with that type of system. “Blow-off valve sound” aside.
Firstly, we need to know what type of engine management can use what type of valve.
Mass AirFlow systems are designed as "closed-loop" systems requiring the use of a recirculating valve.
Speed Density systems are typically setup as closed-loop systems from the factory, but they can typically use either a recirculating OR atmospheric valve without any major detriment to the system.
MAP based systems (manifold absolute pressure) are typically capable of allowing for the use of either valve as well, but most MAP-based systems are fully stand-alone and require significant tuning to overcome any changes.
Now, with that said, the OEM ECU used on the Evo is a Mass Airflow system. It requires the use of a recirculating valve. If anyone, through the course of modifying their car, plans to continue to use the OEM ECU as the base for their engine management (even if some aftermarket tuner has uploaded new programming or a piggyback system is used), it is HIGHLY recommended to continue to use a recirculating valve.
The use of an atmospheric valve will cause a rich fuel mixture due to the loss of already metered air which the ECU is expecting to remain in the system. When the air is vented, the ECU dumps fuel into the system expecting the air to be there, and it's not. This rich fuel condition can sometimes be severe enough that the ECU cannot compensate for the condition and the car will run rough, not idle properly, experience a loss of power, and also experience poor fuel economy.
I have personally seen, on my own vehicle, a loss of as much as roughly 40 miles per full tank of fuel from using an atmospheric valve on a tuned, but otherwise stock engine management system.
If anyone, through the course of modifying their car, plans to switch their engine management from the OEM ECU to some form of standalone engine management (NOT a piggyback system, as even a piggyback still uses the OEM ECU), they can then, and only then, consider the use of an atmospheric valve, as such a system can compensate for, or be tuned to allow for the use of such a valve without any of the problems mentioned above.
50/50 valves, while seemingly great, are not an ideal solution by any measure, in my personal opinion.
(Yes, everything below is a personal opinion and subject to argument, but I’d like to think I know what I’m talking about.)
While they are designed to accomodate those with the desire for an increase in the "blow-off valve sound" from their car, they do so in a way that is still venting metered air, still causing a somewhat richer fuel condition, and still potentially leading to the above mentioned problems. While they may appear to work on any given vehicle, they are only doing so within a window that is not yet necessarily a largely detrimental problem to the OEM ECU at that time and it's ability to alow for the venting of metered air.
The difficulty lies in that there is no precise way to measure, at least cost effectively for aftermarket companies anyway, the PRECISE amount of air that can "safely" be vented out of the system and not cause a problem for the ECU, in whatever it's current state of tune may be, and it's ability to correctly add fuel to the system in the appropriate ratio. There are innumerable factors to consider that will never be perfectly "tuned" in a single 50/50 valve design to suit all applications.
50/50 valves are essentially trying to "trick" the ECU into believing that enough air is still being recirculated to maintain a proper air/fuel ratio under any given load condition, when, in fact, there is no way to effectively know what ratio should be used, if any at all.
The safe bet is to just use a recirulating valve where recommended and enjoy the security that you know that your ECU is not struggling to maintain a proper air/fuel ratio.
If the added sound is REALLY the most important thing to you, however, you must be willing to accept a level of risk that some problems MAY occur.
While it may be nice to have that blow-off valve (whooshing) sound, I personally feel that it's significantly more important to have a valve that will perform and operate properly for the given application regadless of the amount of noise it makes. I do not feel that valves should be designed to make a particular sound, nor to trick their engine management system, whether factory or aftermarket, into thinking the car is operating properly. Valves are meant to perform a specific function that should be done in a manner best suiting the specific application.
The BIG question.
The simple answer:
What kind of valve is your engine management system designed for and/or capable of allowing for the use of?
Yes, I answered a question with another question, but the real answer is, there is no simple answer. Each person will need to consider what their plans for their car are, what type of engine management system they will ultimately be using, and what valve can or can't be used with that type of system. “Blow-off valve sound” aside.
Firstly, we need to know what type of engine management can use what type of valve.
Mass AirFlow systems are designed as "closed-loop" systems requiring the use of a recirculating valve.
Speed Density systems are typically setup as closed-loop systems from the factory, but they can typically use either a recirculating OR atmospheric valve without any major detriment to the system.
MAP based systems (manifold absolute pressure) are typically capable of allowing for the use of either valve as well, but most MAP-based systems are fully stand-alone and require significant tuning to overcome any changes.
Now, with that said, the OEM ECU used on the Evo is a Mass Airflow system. It requires the use of a recirculating valve. If anyone, through the course of modifying their car, plans to continue to use the OEM ECU as the base for their engine management (even if some aftermarket tuner has uploaded new programming or a piggyback system is used), it is HIGHLY recommended to continue to use a recirculating valve.
The use of an atmospheric valve will cause a rich fuel mixture due to the loss of already metered air which the ECU is expecting to remain in the system. When the air is vented, the ECU dumps fuel into the system expecting the air to be there, and it's not. This rich fuel condition can sometimes be severe enough that the ECU cannot compensate for the condition and the car will run rough, not idle properly, experience a loss of power, and also experience poor fuel economy.
I have personally seen, on my own vehicle, a loss of as much as roughly 40 miles per full tank of fuel from using an atmospheric valve on a tuned, but otherwise stock engine management system.
If anyone, through the course of modifying their car, plans to switch their engine management from the OEM ECU to some form of standalone engine management (NOT a piggyback system, as even a piggyback still uses the OEM ECU), they can then, and only then, consider the use of an atmospheric valve, as such a system can compensate for, or be tuned to allow for the use of such a valve without any of the problems mentioned above.
50/50 valves, while seemingly great, are not an ideal solution by any measure, in my personal opinion.
(Yes, everything below is a personal opinion and subject to argument, but I’d like to think I know what I’m talking about.)
While they are designed to accomodate those with the desire for an increase in the "blow-off valve sound" from their car, they do so in a way that is still venting metered air, still causing a somewhat richer fuel condition, and still potentially leading to the above mentioned problems. While they may appear to work on any given vehicle, they are only doing so within a window that is not yet necessarily a largely detrimental problem to the OEM ECU at that time and it's ability to alow for the venting of metered air.
The difficulty lies in that there is no precise way to measure, at least cost effectively for aftermarket companies anyway, the PRECISE amount of air that can "safely" be vented out of the system and not cause a problem for the ECU, in whatever it's current state of tune may be, and it's ability to correctly add fuel to the system in the appropriate ratio. There are innumerable factors to consider that will never be perfectly "tuned" in a single 50/50 valve design to suit all applications.
50/50 valves are essentially trying to "trick" the ECU into believing that enough air is still being recirculated to maintain a proper air/fuel ratio under any given load condition, when, in fact, there is no way to effectively know what ratio should be used, if any at all.
The safe bet is to just use a recirulating valve where recommended and enjoy the security that you know that your ECU is not struggling to maintain a proper air/fuel ratio.
If the added sound is REALLY the most important thing to you, however, you must be willing to accept a level of risk that some problems MAY occur.
While it may be nice to have that blow-off valve (whooshing) sound, I personally feel that it's significantly more important to have a valve that will perform and operate properly for the given application regadless of the amount of noise it makes. I do not feel that valves should be designed to make a particular sound, nor to trick their engine management system, whether factory or aftermarket, into thinking the car is operating properly. Valves are meant to perform a specific function that should be done in a manner best suiting the specific application.
Very good and informative read. Thanks! Now just to clarify, the HKS with the recirc fitting is a recirculating system and not a 50/50, correct? So that system shouldn't cause any problems?
02-24-2007, 08:07 PM
#20
this is an old topic and people have proved that you do not want a bov w/ the s/c setup. I am not posting this to argue but I have been on this form for a few years and from what i have read in the past .... its not a good idea.