Cheap and easy anti-lag device - "D Valve"
07-09-2004, 12:33 AM
#46
Burning Brakes
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Are you sure about the diagram? If so, like what TonyG said... isnt that something similar to BOV?
I still think this valve is unneccessary. But it gave me an idea... how about connecting a similar valve just after the compressor? i.e. under say 5psi of boost, the IC is bypassed.
I still think this valve is unneccessary. But it gave me an idea... how about connecting a similar valve just after the compressor? i.e. under say 5psi of boost, the IC is bypassed.
07-09-2004, 12:35 AM
#47
Rennlist Junkie Forever
Actually... the factory valve is better because it's held open by vacuum any time the engine is under a non-boost situation.. which is 99% for street cars... thus there is zero restriction presented by the turbo compressor, the intercooler, or associated plumbing.
Old news....
TonyG
Old news....
TonyG
07-09-2004, 12:37 AM
#49
Rennlist Junkie Forever
What needs to be fabricated, is a valve that shunts exhaust gas away from the turbine under low load conditions, but closes when the vacuum level lowers to a certain value.
This would have a very good affect on off boost performance.
TonyG
This would have a very good affect on off boost performance.
TonyG
07-09-2004, 02:07 AM
#50
Don't mind some of the other people here.... It's amazing reading the comments I just read. The list is about information and sharing information. You've done just that.
The list is not just about answering questions. Tony G.
DanG, thanks for sharing this information.
The list is not just about answering questions. Tony G.
DanG, thanks for sharing this information.
07-09-2004, 02:28 AM
#51
Rennlist Junkie Forever
beab951
Wow... aren't you sharp! You can't compare the comments I made with those I replied to here in this post with what that jerk made in the post to which you, out-of-context, ripped mine out of. Bad comparision. But nice try.
I just fail to understand how this "anti-lag" device differs from the factory equipped recirculation valve?
What amazes me, is that in 40+ post... nobody "darred" ask the question....
Brian... you seem to be up on things, so please explain how this valve differs, and how we can achieve a performance gain of that over what the factory provided stock.
Thanks in advance,
TonyG
It's pretty funny that the diagram posted was the exact diagram for the factory CBV.
Wow... aren't you sharp! You can't compare the comments I made with those I replied to here in this post with what that jerk made in the post to which you, out-of-context, ripped mine out of. Bad comparision. But nice try.
I just fail to understand how this "anti-lag" device differs from the factory equipped recirculation valve?
What amazes me, is that in 40+ post... nobody "darred" ask the question....
Brian... you seem to be up on things, so please explain how this valve differs, and how we can achieve a performance gain of that over what the factory provided stock.
Thanks in advance,
TonyG
It's pretty funny that the diagram posted was the exact diagram for the factory CBV.
07-09-2004, 02:44 AM
#52
Three Wheelin'
Thread Starter
Tony,
As I said from the very beginning, I have never studied the specific design of the 951 system. I don't doubt that Porsche has beat me (well really whoever I read the idea from) to the punch.
So is there both a CBV and a BOV? Or does one valve allow flow in both directions? Can you describe how the CBV functions in a little more detail? The turbo dodge guys would probably benefit from copying its design.
As I said from the very beginning, I have never studied the specific design of the 951 system. I don't doubt that Porsche has beat me (well really whoever I read the idea from) to the punch.
So is there both a CBV and a BOV? Or does one valve allow flow in both directions? Can you describe how the CBV functions in a little more detail? The turbo dodge guys would probably benefit from copying its design.
07-09-2004, 02:46 AM
#53
Three Wheelin'
Thread Starter
Better yet, is there a good listing of the unique air and fuel management components on a 951? Something similar to the diagram I posted on the first page?
Do you have the factory CBV diagram?
Do you have the factory CBV diagram?
07-09-2004, 02:48 AM
#54
Rennlist Junkie Forever
DanG
First off... I'm not trying to bash you. It's good that you are thinking about these things.
It's just that the stock 951 is equipped with a blow-off valve that dumps right in front of the turbo.
Also, since the blow off valve is connected to the vacuum source of the intake manifold, it remains open at all times when the engine is under vacuum conditions, thus bypassing the turbo compressor, intercooler, and associated plumbing.
The diagram that was submitted previously on this post, is the exact plumbing diagram of the factory CBV (compressor bypass valve).
Your 951 already has this.
TonyG
First off... I'm not trying to bash you. It's good that you are thinking about these things.
It's just that the stock 951 is equipped with a blow-off valve that dumps right in front of the turbo.
Also, since the blow off valve is connected to the vacuum source of the intake manifold, it remains open at all times when the engine is under vacuum conditions, thus bypassing the turbo compressor, intercooler, and associated plumbing.
The diagram that was submitted previously on this post, is the exact plumbing diagram of the factory CBV (compressor bypass valve).
Your 951 already has this.
TonyG
07-09-2004, 02:58 AM
#55
Rennlist Junkie Forever
DanG
Look around on the internet, or open up your hood and look at the stickers... or get a factory manual or even an aftermarket manual.
The system on the 951 is not really unique at all or even semi-sophisticated. It's rather plain-jane....
TonyG
Look around on the internet, or open up your hood and look at the stickers... or get a factory manual or even an aftermarket manual.
The system on the 951 is not really unique at all or even semi-sophisticated. It's rather plain-jane....
TonyG
07-09-2004, 03:08 AM
#56
Three Wheelin'
Thread Starter
No bash taken. BTW, I'm still a lowly non-turbo owner. Never seen under the hood (in person) or even worse, driven a 951. Its on my shopping list this fall.
I'm still not sure if we're on the same page. Does the CBV = BOV? As in CBV sucks atmospheric pressure through the valve when the rest of the intake is in vaccum and BOV vents positive pressure when the turbo side of the TB is higher than the combustion side.
Unless they're two separate components, then the BOVs I'm aware of do not really provide the kind of flow that this simple check valve is capable of. I tried to reason this out earlier in the thread. Basically in the conditions I'm talking about (vaccum on BOTH sides of a WIDE OPEN throttle body), the BOV will only open a proportionate amount to the difference in areas of the top diaphram and lower valve, MINUS the spring force. So unless there's a considerable pressure differential on either side of the TB, that valve can be considered closed.
I'm still not sure if we're on the same page. Does the CBV = BOV? As in CBV sucks atmospheric pressure through the valve when the rest of the intake is in vaccum and BOV vents positive pressure when the turbo side of the TB is higher than the combustion side.
Unless they're two separate components, then the BOVs I'm aware of do not really provide the kind of flow that this simple check valve is capable of. I tried to reason this out earlier in the thread. Basically in the conditions I'm talking about (vaccum on BOTH sides of a WIDE OPEN throttle body), the BOV will only open a proportionate amount to the difference in areas of the top diaphram and lower valve, MINUS the spring force. So unless there's a considerable pressure differential on either side of the TB, that valve can be considered closed.
07-09-2004, 11:04 AM
#57
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I am not an expert on this subject, but isn't this similar to the discussion about the difference between a Blow-off Valve (BOV) and a Bypass Valve/Recirculation Valve/Diverter Valve?
In stock form, the 951 (along with most of the Audi, VW, other Porsche, even a MR2 Turbo...these are the only turbos I am familiar with) is configured with a Bypass Valve that dumps this air back into the intake.
Some opt to eliminate this system and replace it with a Blow-off Valve. The BOV serves the same initial purpose but dumps the air to atmosphere instead of back into the intake.
Maybe your Dodge guys are using BOVs that vent to atmosphere and this allows them to recirculate some air...thus enhancing spool up.
Is this right, Tony? Also, to give credit, Wormhole and Dal Heger mentioned this earlier, but it was not recognized.
As an aside, what is new these days Tony? What's your new project?
Max
In stock form, the 951 (along with most of the Audi, VW, other Porsche, even a MR2 Turbo...these are the only turbos I am familiar with) is configured with a Bypass Valve that dumps this air back into the intake.
Some opt to eliminate this system and replace it with a Blow-off Valve. The BOV serves the same initial purpose but dumps the air to atmosphere instead of back into the intake.
Maybe your Dodge guys are using BOVs that vent to atmosphere and this allows them to recirculate some air...thus enhancing spool up.
Is this right, Tony? Also, to give credit, Wormhole and Dal Heger mentioned this earlier, but it was not recognized.
As an aside, what is new these days Tony? What's your new project?
Max
07-09-2004, 05:25 PM
#58
Drifting
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So if Tony's explanation is correct,
we would be better off getting
a mega size recirculating valve.
More air equals better throttle
response right ? In theory yes
it sounds correct but maybe in
reality it could be different.
we would be better off getting
a mega size recirculating valve.
More air equals better throttle
response right ? In theory yes
it sounds correct but maybe in
reality it could be different.
07-09-2004, 10:55 PM
#59
OK i know this thing doesn't work on my car.
With my set up, the bypass is usless because my GT30R generate enough flow at idle to overcome the vacum in the motor.
Since i run a Map kit, i can run my car without intercoller pipes.
So to test this bypass thing. I just openned up a 3/4'' hole i have in my intercooler to TB pipe.
AT idle, it blow out pressure. Not even close to get a vacum out of this car.
Even when i was giving big gas shots, fast or slow. It always shot out pressure.
So if my GT30R does that with a bigger .63A/R. I presume it does the same with a smaller factory turbo.
Anybody else tried it?
With my set up, the bypass is usless because my GT30R generate enough flow at idle to overcome the vacum in the motor.
Since i run a Map kit, i can run my car without intercoller pipes.
So to test this bypass thing. I just openned up a 3/4'' hole i have in my intercooler to TB pipe.
AT idle, it blow out pressure. Not even close to get a vacum out of this car.
Even when i was giving big gas shots, fast or slow. It always shot out pressure.
So if my GT30R does that with a bigger .63A/R. I presume it does the same with a smaller factory turbo.
Anybody else tried it?
07-10-2004, 02:28 AM
#60
Drifting
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Hey Edman,
How's your car running now ? Any dyno
figures ? On the final leg on my GT25
install. I had to do much more mods than
yours. Now having a major pain in getting
a custom crossover & down pipe welded.
BTW Edman, the Check Valve should close
when it senses pressure not open. Also
a more accurrate test would be to have
everything connected.
How's your car running now ? Any dyno
figures ? On the final leg on my GT25
install. I had to do much more mods than
yours. Now having a major pain in getting
a custom crossover & down pipe welded.
BTW Edman, the Check Valve should close
when it senses pressure not open. Also
a more accurrate test would be to have
everything connected.