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Has anyone played with this yet? I got a print out from a dealer on some parts and I have a few things I think make the boost cut out in the first two gears. There is a solenoid that goes from the top of the wastegate to the intake. I have not seen one of these before. I have a turbo Eclipse that I drag, and I have not seen this on the Eclipse. Does anyone know what it is exactly. The dealer just said it is a solenoid, but they could not tell me what type it was. I have some stuff to share, but nowhere to put it so others can access it.

Jeff
 

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There is an air bypass valve that the ECU uses to control boost pressure.
When the valve is fully closed, the wastegate will open at a relatively low pressure.
The ECU will modulate this valve in varying degrees to allow some of the air to bypass the wastegate which will cause the wastegate to open at a higher boost pressure.

Realistically speaking, you cannot remove or disconnect this valve.
 

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the drive by wire system essentially reduces boost in 1,2 and 3. I don't think it is easily defeated. apparantly, boost is not limited by intentionally bleeding boost through wastegate, which some wondered, but rather by the control of the throttle (drive by wire)
 

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^^ where is the proof of dbw related reduced boost in 3rd? boost is related to engine load, so just because 4th shows more boost than in 3rd doesnt equal that the ecu is pulling boost in 3rd. I hate when rumors get started based upon bad guesses.
 

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[quote author=CosmicBlueMS3 link=topic=65726.msg1126374#msg1126374 date=1167516274]
^^ where is the proof of dbw related reduced boost in 3rd? boost is related to engine load, so just because 4th shows more boost than in 3rd doesnt equal that the ecu is pulling boost in 3rd. I hate when rumors get started based upon bad guesses.
[/quote]

i read that in a technical article on the MS3 engine technology in SCC today...the issue with the gti shootout. dont forget, the 2.3T mazda engine is using some pretty neat 'new' technologies not often seen on turbod cars previously, even the direct injection is different than audis....so why is it so hard to belive that they could program the ecu to limit boost in cooperation with throttle control/dbw
 

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the article specifically states boost is reduced in 3rd? I dont doubt its possible, I just question if its actually true. I have seen a few non owners in this forum yelling that the sky is falling by believing everything they read as the gospel. I just dont want to put the car before the mule so to speak. I like concrete proof / numbers to backup these "new" findings.
 

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Discussion Starter #7
I installed the boost guage and took it for a spin. I do get boost in 2nd gear, and up. I did not look at it in 1st but it spiked in every gear up to 20lbs then back down to 15ish. I am going to have to add a MBC and crank the boost up a bit. I want to see if it will still regulate it back down to 15psi.
 

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I look forward to seeing your results. I know there are ms6 guys running mbc's and holding higher values, so dont see why it wouldnt work for us, but so far I dont know anyone here who has tried yet.
 

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Discussion Starter #9
Nobody has balls here? :lol:

I will more than likely play with the boost tomorrow. I have a feeling that it is going to bleed off the extra boost. I don't know if the BOV will take a constant pressure over 15psi either. I guess I will find out. Also, the little solenoid that comes off the wastegate actuator (spelling), is that regulating the boost? I wonder if it is some kind of pressure sensor that opens up to let the extra boost through too. I am still trying to figure out that thing. Usually there is just one vac line off the top of the actuator and it opens up at xpsi of boost, not holding more than the preset value.
 

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pioneers are few and far between. :D
my excuse is that I plan to race my ms3 in classes that are very strict concerning what mods can be done to the car and currently I dont even know what class im prepping my car to run in. I would love to put every go fast mod on my car asap, but unfortunately if I did, it would make me brutally uneffective on race day.
 

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Discussion Starter #11
Depends on what kind of racing you are doing. I know where you are coming from though. Ususally boost controllers does not constitute you moving up a class. I am not 100% though.
 

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I'm not sure why this hasnt been said.

The mazdaspeed 3 ecu limits boost in 1st and 2nd gear to prevent excessive wheelspin/torque steer. It will only boost up to 10psi (spike) in 1st and 2nd, then give you full boost of 16psi (spikes) from 3rd gear and up.
 

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[quote author=Nutari link=topic=65726.msg1126751#msg1126751 date=1167539769]
I'm not sure why this hasnt been said.

The mazdaspeed 3 ecu limits boost in 1st and 2nd gear to prevent excessive wheelspin/torque steer. It will only boost up to 10psi (spike) in 1st and 2nd, then give you full boost of 16psi (spikes) from 3rd gear and up.


[/quote]
That is not what really happens.
Actual boost pressure in each gear is highly variable depending upon a number of conditions.
Based on my experiences so far, I would describe the ECU as paranoid schizophrenic.
 

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[quote author=eclipses20g link=topic=65726.msg1126680#msg1126680 date=1167535364]


Also, the little solenoid that comes off the wastegate actuator (spelling), is that regulating the boost? I wonder if it is some kind of pressure sensor that opens up to let the extra boost through too. I am still trying to figure out that thing. Usually there is just one vac line off the top of the actuator and it opens up at xpsi of boost, not holding more than the preset value.
[/quote]
For an explanation of that solenoid (actually a valve), read the second post:

http://www.mazda3forums.com/index.php?topic=65726.0
 

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[quote author=GT1 link=topic=65726.msg1126796#msg1126796 date=1167543772]
[quote author=Nutari link=topic=65726.msg1126751#msg1126751 date=1167539769]
I'm not sure why this hasnt been said.

The mazdaspeed 3 ecu limits boost in 1st and 2nd gear to prevent excessive wheelspin/torque steer. It will only boost up to 10psi (spike) in 1st and 2nd, then give you full boost of 16psi (spikes) from 3rd gear and up.


[/quote]
That is not what really happens.
Actual boost pressure in each gear is highly variable depending upon a number of conditions.
Based on my experiences so far, I would describe the ECU as paranoid schizophrenic.

[/quote]

I think Nutari was just wondering how he was getting spikes to 20 that settle down to 15 in 2nd. Just curious, what other variables have you discovered besides wheel angle in 3rd and up?
 

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[quote author=CosmicBlueMS3 link=topic=65726.msg1126614#msg1126614 date=1167531564]
the article specifically states boost is reduced in 3rd? I dont doubt its possible, I just question if its actually true. I have seen a few non owners in this forum yelling that the sky is falling by believing everything they read as the gospel. I just dont want to put the car before the mule so to speak. I like concrete proof / numbers to backup these "new" findings.
[/quote]

yup, I was surprised when I read it. I should have bought the mag so I could write an exact quote. they said the dbw system regulates boost through 1,2, 3rd gear. perhaps they know something we dont...or something mazda has disclosed to them? they did get the first real track test and test mule car from mazda didn't they? cant recall....anyway...like you, I would like proof as well. perhaps it is just an editors error....but maybe not.
 

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[quote author=dutchie3 link=topic=65726.msg1127009#msg1127009 date=1167579008]
[quote author=CosmicBlueMS3 link=topic=65726.msg1126614#msg1126614 date=1167531564]
the article specifically states boost is reduced in 3rd? I dont doubt its possible, I just question if its actually true. I have seen a few non owners in this forum yelling that the sky is falling by believing everything they read as the gospel. I just dont want to put the car before the mule so to speak. I like concrete proof / numbers to backup these "new" findings.
[/quote]

yup, I was surprised when I read it. I should have bought the mag so I could write an exact quote. they said the dbw system regulates boost through 1,2, 3rd gear. perhaps they know something we dont...or something mazda has disclosed to them? they did get the first real track test and test mule car from mazda didn't they? cant recall....anyway...like you, I would like proof as well. perhaps it is just an editors error....but maybe not.
[/quote]

What did you want proof of?

Just to warn you.. I dropped the camera at the end..

http://s6.photobucket.com/albums/y241/Deathwater/mazda/?action=view&current=MOV02988.flv
 

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nutari are you holding higher than 12psi in any gear? I think now with the bigger tmic a boost controller is going to be needed to smooth things out.

what i gathered the sustained boost levels were
1st 5 psi
2nd 11 psi
3rd 12 psi
4th 12 psi
is this what you are normally getting?

btw, whats up with that G-Fab guage holder :p
 
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