MB OEM Supercharger Bypass Valve
04-22-2007, 05:02 AM
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10' GLK
MB OEM Supercharger Bypass Valve
Where can i find a diagram of the (stock C230 compressor model) engine by pass valve?
There's basically 3 hoses, one is the venting hose that route compressed air back to the intake, and there's two small hoses. One's from the middle of the Bypass valve, one's on top of the valve itself.
Can someone tell me where exactly are these 2 little hoses connected to? mainfold pressure? solenoid? Please school me. Or show me a diagram please
There's basically 3 hoses, one is the venting hose that route compressed air back to the intake, and there's two small hoses. One's from the middle of the Bypass valve, one's on top of the valve itself.
Can someone tell me where exactly are these 2 little hoses connected to? mainfold pressure? solenoid? Please school me. Or show me a diagram please
04-22-2007, 05:34 AM
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Midnight Blue 2004.5 C230 Kompressor Sport Sedan. 2002 w210 E320, 2009 w211 E350 Sport
Where can i find a diagram of the (stock C230 compressor model) engine by pass valve?
There's basically 3 hoses, one is the venting hose that route compressed air back to the intake, and there's two small hoses. One's from the middle of the Bypass valve, one's on top of the valve itself.
Can someone tell me where exactly are these 2 little hoses connected to? mainfold pressure? solenoid? Please school me. Or show me a diagram please
There's basically 3 hoses, one is the venting hose that route compressed air back to the intake, and there's two small hoses. One's from the middle of the Bypass valve, one's on top of the valve itself.
Can someone tell me where exactly are these 2 little hoses connected to? mainfold pressure? solenoid? Please school me. Or show me a diagram please
04-22-2007, 02:27 PM
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Midnight Blue 2004.5 C230 Kompressor Sport Sedan. 2002 w210 E320, 2009 w211 E350 Sport
I do have pics of the m271 engine at work. There is also another thread that already had engine pics. Search for "supercharger porting" and you'll find the thread I'm talking about.
04-23-2007, 01:18 AM
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10' GLK
I don't have a diagram here, but you have the m271 engine. Update your profile, so that people know how to reply to you. The m111 was in the 2002 230 coupe. The m271 was in the 2003-2005 Sport sedan and 2003-2004 coupe (The cl203 was discontinued in 2005).
I do have pics of the m271 engine at work. There is also another thread that already had engine pics. Search for "supercharger porting" and you'll find the thread I'm talking about.
I do have pics of the m271 engine at work. There is also another thread that already had engine pics. Search for "supercharger porting" and you'll find the thread I'm talking about.
Actually, I don't have a MB, it's my girlfriends 2005 C230K coupe(it's a Canadian version), I personally drive a Subaru.
I ask for a diagram just because my gf is begging me to look into a BOV for her. I took a look at the stock BPV location and see that it is absolutely possible to mount an aftermarket BOV on the M271 with just a custom flange. Usually, our Subaru have 1 small air hose that connects to the top part of the BPV, but the MB 230K engine comes with 2 small hose + 1 recirculate hose. I don't have any detail diagrams to see why it's 2 hoses on the MB. I'll start digging more into this engine later on my spare time.
However, even if i can physically fit (with custom flange) an aftermarket BOV on the stock engine, I'll have to figure out if there's any adverse problem electronically.
You guys can call me rice.
04-23-2007, 01:38 AM
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'05 C230SS 6MT, 1966 Triumph TR4a IRS, Shelby Cobra 427 Supercharged
I'm bored so I'll chime in! LOL!
The bypass valve on a supercharged motor puts the extra air from the SC back into the airbox when the engine is under low load. This is so that you get good fuel economy, but when you need it, the bypass valve closes so that the air is actually forced into the motor. Its not the same as a BOV on a turbo motor. I dont see any advantage to going to a aftermarket valve. It wont even make a sound, well maybe like a leaking airhose! Although I may be wrong, some one feel free to correct me.
The bypass valve on a supercharged motor puts the extra air from the SC back into the airbox when the engine is under low load. This is so that you get good fuel economy, but when you need it, the bypass valve closes so that the air is actually forced into the motor. Its not the same as a BOV on a turbo motor. I dont see any advantage to going to a aftermarket valve. It wont even make a sound, well maybe like a leaking airhose! Although I may be wrong, some one feel free to correct me.
04-23-2007, 03:02 AM
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10' GLK
I'm bored so I'll chime in! LOL!
The bypass valve on a supercharged motor puts the extra air from the SC back into the airbox when the engine is under low load. This is so that you get good fuel economy, but when you need it, the bypass valve closes so that the air is actually forced into the motor. Its not the same as a BOV on a turbo motor. I dont see any advantage to going to a aftermarket valve. It wont even make a sound, well maybe like a leaking airhose! Although I may be wrong, some one feel free to correct me.
The bypass valve on a supercharged motor puts the extra air from the SC back into the airbox when the engine is under low load. This is so that you get good fuel economy, but when you need it, the bypass valve closes so that the air is actually forced into the motor. Its not the same as a BOV on a turbo motor. I dont see any advantage to going to a aftermarket valve. It wont even make a sound, well maybe like a leaking airhose! Although I may be wrong, some one feel free to correct me.
I'm still a noob for superchargers, however, I'm a pretty well informed turbo motor user.
The bpv won't open or close solely based on the load of the engine. Stock BPV will hold the compressed air between the supercharger and throttle body. If there's excessive compressed air between supercharger and throttle body, say at 14 psi, you decided to let off the throttle, the bpv will recirculate the unused air between the supercharger and throttle back to the intake tract. The stock bpv won't make any sound because of the recirculation, however, if you install an aftermarket blow off, it will.
On the M271, i see that it's possible with a custom flange and bov base. Some aluminum welding and a plug for the stock recirculate hose will do it. The only draw back is the drive by cable on the MB, on the Subaru, it's possible with either drive by wire or cable.
Also, if you want blow off sound, changing the rubber recirculate hose to a metal pipe will produce that sound. However, the supercharger muffler will kill most of that blow off sound.
All in all, i'm just seeking for the blow off sound, i know fully about the pro's and con's of a bov vs. bpv. i.e. lean/rich , cel codes, rice/not rice, ...etc.
Please correct me if i'm wrong on this topic, my knowledge mostly come from my 6 years of subaru ownership.
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04-23-2007, 10:19 AM
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'05 C230SS 6MT, 1966 Triumph TR4a IRS, Shelby Cobra 427 Supercharged
When I said load, I was just simplifying it. Its based off of vacuum, which is a way to tell if it is under load or not, or more of whether the engine is sucking in more air because the throttle butterfly is open more (meaning you are accelerating, or pulling something hence load). The valve is normally open so that the air recirculates. For example, say you are on the parkway doing 70mph at 3000RPM. The SC would be spinning at about 50%, but you don't need that because you're not accelerating. So the valve stays open. But when you step on the gas and the vacuum indicates that you are asking for more power, the valve closes so that the SC can do its job answering your request with some boost. Then when you let off the gas, you don't need that boost anymore so the valve opens to recirculate. Its not because of excessive boost, cause that just doesn't happen with an SC. So its not like a turbo motor where your set up to take in 14 PSI and when you shift and now at a lower rpm that boost becomes 30 PSI, the BOV "pops" so that it stays at 14 PSI. An SC does that automatically because it makes its boost according to engine speed. That being said, when you shift with an SC, you want that valve to stay closed so that you don't loose boost in the shift. Changing that valve to one that is noisy wont give you that "Pop" sound like a turbo BOV, it will give you a sound like a leaky air hose when you're not using boost, which is the majority of the time.
And as far as it being controlled by vacuum, thats how its supposed to work, but this is MB we're talking about, and they feel the excessive need to control everything through a computer! So rather than a vacuum motor, it maybe a solenoid controlled by various other parameters monitored by the ECU.
If you really want the BOV sound, you can buy one of those things off of eBay that make a fake BOV sound...
http://cgi.ebay.com/ebaymotors/Lexus...10443054QQrdZ1
And as far as it being controlled by vacuum, thats how its supposed to work, but this is MB we're talking about, and they feel the excessive need to control everything through a computer! So rather than a vacuum motor, it maybe a solenoid controlled by various other parameters monitored by the ECU.
If you really want the BOV sound, you can buy one of those things off of eBay that make a fake BOV sound...
http://cgi.ebay.com/ebaymotors/Lexus...10443054QQrdZ1
Last edited by Capt Nemo o2; 04-23-2007 at 10:24 AM.
04-24-2007, 02:32 AM
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When I said load, I was just simplifying it. Its based off of vacuum, which is a way to tell if it is under load or not, or more of whether the engine is sucking in more air because the throttle butterfly is open more (meaning you are accelerating, or pulling something hence load). The valve is normally open so that the air recirculates. For example, say you are on the parkway doing 70mph at 3000RPM. The SC would be spinning at about 50%, but you don't need that because you're not accelerating. So the valve stays open. But when you step on the gas and the vacuum indicates that you are asking for more power, the valve closes so that the SC can do its job answering your request with some boost. Then when you let off the gas, you don't need that boost anymore so the valve opens to recirculate. Its not because of excessive boost, cause that just doesn't happen with an SC. So its not like a turbo motor where your set up to take in 14 PSI and when you shift and now at a lower rpm that boost becomes 30 PSI, the BOV "pops" so that it stays at 14 PSI. An SC does that automatically because it makes its boost according to engine speed. That being said, when you shift with an SC, you want that valve to stay closed so that you don't loose boost in the shift. Changing that valve to one that is noisy wont give you that "Pop" sound like a turbo BOV, it will give you a sound like a leaky air hose when you're not using boost, which is the majority of the time.
And as far as it being controlled by vacuum, thats how its supposed to work, but this is MB we're talking about, and they feel the excessive need to control everything through a computer! So rather than a vacuum motor, it maybe a solenoid controlled by various other parameters monitored by the ECU.
If you really want the BOV sound, you can buy one of those things off of eBay that make a fake BOV sound...
http://cgi.ebay.com/ebaymotors/Lexus...10443054QQrdZ1
And as far as it being controlled by vacuum, thats how its supposed to work, but this is MB we're talking about, and they feel the excessive need to control everything through a computer! So rather than a vacuum motor, it maybe a solenoid controlled by various other parameters monitored by the ECU.
If you really want the BOV sound, you can buy one of those things off of eBay that make a fake BOV sound...
http://cgi.ebay.com/ebaymotors/Lexus...10443054QQrdZ1
Anyways, I'll look more into the MB engine soon and hopefully test fit a bov on this engine to justify my thinking. And I KNEW someone will bring that ebay fake BOV thing up. You are so funny ! I've the BOV sound on my turbo subaru already. And I've way faster euro cars than the MB to boot around as well. So, need no ebay fake bov on MB. Thanks.
so, still no one have helpful answers to my question from the beginning instead of schooling me on what a BOV on forced induction engine does?
Last edited by bwco; 04-24-2007 at 02:34 AM.
05-14-2007, 06:38 AM
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Superchargers have larger and heavier internals than turbochargers
If, when you hit the gas about midway (mid throttle but no boost yet, yet high demand) that inrush of air that you are demanding will not reach the engine instantly because it has to go through the supercharger.
This delay will cause a lag much like turbo lag on throttle input, further, it will decrease fuel effeciency for 2 reasons
1- all the air you're injesting in around town driving would be hot having run through the supercharger
2- you will waist some 10-15 hp of 'milage' always driving the supercharger (and as you know it's not a light thing to drive like a ceramic turbo compressor wheel).
To solve this, supercharges use BYPASS VALVE S (not blow off valves)
a blow off valve vents air on throttle lift to prevent compressor surge.
a bypass valve has 2 functions
1- it vents air on throttle lift to prevent compressor surge
2- it completely BYPASSES the compressor (be it a turbo or a supercharger) on high vacuum / high demand situations to promote throttle response and high effeciency (milage) under off boost driving conditions.
If you took out your stock electronic bypass valve and installed a blow off valve your drivability will suck, your thorttle response will be ****, and your milage will drop significantly as you will technically ALWAYS BE using your supercharger...and very quick into boost (which can hurt traction too)....
the old style bypass valves (like the ones that come on stock mr2 turbos, stock 911 turbos, stock saabs..etc) are vacuum referenced
at high vacuum it will bypass ... this high vacuum is present in 2 situations
1- throttle lift (so it will work as a blow off)
2- high pressure differencial between manifold vacuum and inlet vacuum (ie high demand/high restriction situations where the S/C is 'lagging' or choking the airflow
Newer cars are more fancy using an electronic bypass valve.
With this bypass valve mercedes can do 2 things
1- simulate a mechanical (vacuum referenced) bypass valve
2- limit boost in situations where it wants to (such as traction control for example... the ecu is able to reduce torque output by reducing throttle angle, and opening the bypass valve dropping you out of boost...and then with the aid of selective braking, the ecu is able to re-stabilize the car using ESP)
another nifty feature to this electronic bypass valve is that mercedes if they want to can use it kind of like a wastegate...where they can open it to limit your boost, or limit your 'spool' (how fast the boost builds) even on a roots type supercharger.
The only performance gain i can see would be this:
Adapter plate with a mechanical (Bosch, bailey, vortech) BYPASS valve
This removes any kind of boost limit the ECU can induce through messing with the electronic bypass
if you just want a blow off valve sound... it's a worthless mod
If, when you hit the gas about midway (mid throttle but no boost yet, yet high demand) that inrush of air that you are demanding will not reach the engine instantly because it has to go through the supercharger.
This delay will cause a lag much like turbo lag on throttle input, further, it will decrease fuel effeciency for 2 reasons
1- all the air you're injesting in around town driving would be hot having run through the supercharger
2- you will waist some 10-15 hp of 'milage' always driving the supercharger (and as you know it's not a light thing to drive like a ceramic turbo compressor wheel).
To solve this, supercharges use BYPASS VALVE S (not blow off valves)
a blow off valve vents air on throttle lift to prevent compressor surge.
a bypass valve has 2 functions
1- it vents air on throttle lift to prevent compressor surge
2- it completely BYPASSES the compressor (be it a turbo or a supercharger) on high vacuum / high demand situations to promote throttle response and high effeciency (milage) under off boost driving conditions.
If you took out your stock electronic bypass valve and installed a blow off valve your drivability will suck, your thorttle response will be ****, and your milage will drop significantly as you will technically ALWAYS BE using your supercharger...and very quick into boost (which can hurt traction too)....
the old style bypass valves (like the ones that come on stock mr2 turbos, stock 911 turbos, stock saabs..etc) are vacuum referenced
at high vacuum it will bypass ... this high vacuum is present in 2 situations
1- throttle lift (so it will work as a blow off)
2- high pressure differencial between manifold vacuum and inlet vacuum (ie high demand/high restriction situations where the S/C is 'lagging' or choking the airflow
Newer cars are more fancy using an electronic bypass valve.
With this bypass valve mercedes can do 2 things
1- simulate a mechanical (vacuum referenced) bypass valve
2- limit boost in situations where it wants to (such as traction control for example... the ecu is able to reduce torque output by reducing throttle angle, and opening the bypass valve dropping you out of boost...and then with the aid of selective braking, the ecu is able to re-stabilize the car using ESP)
another nifty feature to this electronic bypass valve is that mercedes if they want to can use it kind of like a wastegate...where they can open it to limit your boost, or limit your 'spool' (how fast the boost builds) even on a roots type supercharger.
The only performance gain i can see would be this:
Adapter plate with a mechanical (Bosch, bailey, vortech) BYPASS valve
This removes any kind of boost limit the ECU can induce through messing with the electronic bypass
if you just want a blow off valve sound... it's a worthless mod
05-14-2007, 05:02 PM
#11
MBWorld Fanatic!
LOL!!!
Wow, thats right up there with the fake cell phone antenna's people used to put on their cars! Or even the fake cell phones so you could look cool like you're on a cell phone back when they were expensive...
freakin' stupid!
If you really want the BOV sound, you can buy one of those things off of eBay that make a fake BOV sound...
http://cgi.ebay.com/ebaymotors/Lexus...10443054QQrdZ1
Wow, thats right up there with the fake cell phone antenna's people used to put on their cars! Or even the fake cell phones so you could look cool like you're on a cell phone back when they were expensive...
freakin' stupid!
If you really want the BOV sound, you can buy one of those things off of eBay that make a fake BOV sound...
http://cgi.ebay.com/ebaymotors/Lexus...10443054QQrdZ1
03-03-2013, 11:49 PM
#12
Member
Superchargers have larger and heavier internals than turbochargers
If, when you hit the gas about midway (mid throttle but no boost yet, yet high demand) that inrush of air that you are demanding will not reach the engine instantly because it has to go through the supercharger.
This delay will cause a lag much like turbo lag on throttle input, further, it will decrease fuel effeciency for 2 reasons
1- all the air you're injesting in around town driving would be hot having run through the supercharger
2- you will waist some 10-15 hp of 'milage' always driving the supercharger (and as you know it's not a light thing to drive like a ceramic turbo compressor wheel).
To solve this, supercharges use BYPASS VALVE S (not blow off valves)
a blow off valve vents air on throttle lift to prevent compressor surge.
a bypass valve has 2 functions
1- it vents air on throttle lift to prevent compressor surge
2- it completely BYPASSES the compressor (be it a turbo or a supercharger) on high vacuum / high demand situations to promote throttle response and high effeciency (milage) under off boost driving conditions.
If you took out your stock electronic bypass valve and installed a blow off valve your drivability will suck, your thorttle response will be ****, and your milage will drop significantly as you will technically ALWAYS BE using your supercharger...and very quick into boost (which can hurt traction too)....
the old style bypass valves (like the ones that come on stock mr2 turbos, stock 911 turbos, stock saabs..etc) are vacuum referenced
at high vacuum it will bypass ... this high vacuum is present in 2 situations
1- throttle lift (so it will work as a blow off)
2- high pressure differencial between manifold vacuum and inlet vacuum (ie high demand/high restriction situations where the S/C is 'lagging' or choking the airflow
Newer cars are more fancy using an electronic bypass valve.
With this bypass valve mercedes can do 2 things
1- simulate a mechanical (vacuum referenced) bypass valve
2- limit boost in situations where it wants to (such as traction control for example... the ecu is able to reduce torque output by reducing throttle angle, and opening the bypass valve dropping you out of boost...and then with the aid of selective braking, the ecu is able to re-stabilize the car using ESP)
another nifty feature to this electronic bypass valve is that mercedes if they want to can use it kind of like a wastegate...where they can open it to limit your boost, or limit your 'spool' (how fast the boost builds) even on a roots type supercharger.
The only performance gain i can see would be this:
Adapter plate with a mechanical (Bosch, bailey, vortech) BYPASS valve
This removes any kind of boost limit the ECU can induce through messing with the electronic bypass
if you just want a blow off valve sound... it's a worthless mod
If, when you hit the gas about midway (mid throttle but no boost yet, yet high demand) that inrush of air that you are demanding will not reach the engine instantly because it has to go through the supercharger.
This delay will cause a lag much like turbo lag on throttle input, further, it will decrease fuel effeciency for 2 reasons
1- all the air you're injesting in around town driving would be hot having run through the supercharger
2- you will waist some 10-15 hp of 'milage' always driving the supercharger (and as you know it's not a light thing to drive like a ceramic turbo compressor wheel).
To solve this, supercharges use BYPASS VALVE S (not blow off valves)
a blow off valve vents air on throttle lift to prevent compressor surge.
a bypass valve has 2 functions
1- it vents air on throttle lift to prevent compressor surge
2- it completely BYPASSES the compressor (be it a turbo or a supercharger) on high vacuum / high demand situations to promote throttle response and high effeciency (milage) under off boost driving conditions.
If you took out your stock electronic bypass valve and installed a blow off valve your drivability will suck, your thorttle response will be ****, and your milage will drop significantly as you will technically ALWAYS BE using your supercharger...and very quick into boost (which can hurt traction too)....
the old style bypass valves (like the ones that come on stock mr2 turbos, stock 911 turbos, stock saabs..etc) are vacuum referenced
at high vacuum it will bypass ... this high vacuum is present in 2 situations
1- throttle lift (so it will work as a blow off)
2- high pressure differencial between manifold vacuum and inlet vacuum (ie high demand/high restriction situations where the S/C is 'lagging' or choking the airflow
Newer cars are more fancy using an electronic bypass valve.
With this bypass valve mercedes can do 2 things
1- simulate a mechanical (vacuum referenced) bypass valve
2- limit boost in situations where it wants to (such as traction control for example... the ecu is able to reduce torque output by reducing throttle angle, and opening the bypass valve dropping you out of boost...and then with the aid of selective braking, the ecu is able to re-stabilize the car using ESP)
another nifty feature to this electronic bypass valve is that mercedes if they want to can use it kind of like a wastegate...where they can open it to limit your boost, or limit your 'spool' (how fast the boost builds) even on a roots type supercharger.
The only performance gain i can see would be this:
Adapter plate with a mechanical (Bosch, bailey, vortech) BYPASS valve
This removes any kind of boost limit the ECU can induce through messing with the electronic bypass
if you just want a blow off valve sound... it's a worthless mod
Also how will mileage be affected at low rpm? Will mpg still be lowered drastically?
After doing a couple of resets on my bypass valve I feel it still does not work 100% properly. I still have to drive it a little more to confirm this.
I was contemplating on temporarily putting a straight intake to my supercharger and blocking the opening for the bypass valve on my supercharger until I get a new bypass valve setup. It seems like it could cause detrimental effects. Any comments?
Don't mean to be asking a stupid question, I completely understand what the function of the bypass valve.
