~~~~~~~~~~~~~~~~~~~ Pontiac builds excitement... Saturn has rethought it's image...
The time has come for the enthusiasts... NASSOA
Founding Member - Recording Secretary - Northeast ~~~~~~~~~~~~~~~~~~~
Location: Rosamond, CA - Home of Willow Springs Raceway
There's another thread around here where one of the vendors may install a BOV with the intercooler pipes he'll be offering.
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2007 Cool GXP with Darkside Top, 5 spd, Ebony Cloth, Monsoon with Single CD, Sport Pedals, XM, A/C
Mods - Solo Street/Race Exhaust, K&N Drop-in Air Filter, EDAL
Normally when you install a bov in a car with a mas it runs a bit rich during shifts since there's less air in the mixture. But since the gxp has a wideband a/f odds are it might adjust for that small rich spike in the a/f.
The idle might also suffer a bit, as in drop below 750rpm when you shift and let the rpm's drop. Maybe the guys at exhaust depot can comment on this since they're the only ones who put a bov on the gxp so far.
... Maybe the guys at exhaust depot can comment on this since they're the only ones who put a bov on the gxp so far.
You mean they're the only ones who put ANOTHER bov on the GXP so far. Ours already has one integral with the turbo, but ED feels (IIRC) that a second one helps with the acceleration time of the turbine wheel to spool up, or something like that!
__________________
Her name is Roxy!
Mods:
Removed front plate
Kappasphere CAI
Exhaust Depot intercooler pipes
Lil' Chromies
Kappapouches
Kappabrella
"NON SIBI SED PATRIAE" ("Not for Self but for Country") - Cicero
I really dont see how a bov can help in acceleration, its closed when the car is accelerating.
Im sure the "gains" that he felt were more with the uncrushed pipes he installed then with the bov. A bov simply releases pressure from the pipes/ic when you close the throttle plate, thats it.
I really dont see how a bov can help in acceleration, its closed when the car is accelerating.
Im sure the "gains" that he felt were more with the uncrushed pipes he installed then with the bov. A bov simply releases pressure from the pipes/ic when you close the throttle plate, thats it.
This is how a BOV WORKS:
The turbo can spool up to 100k RPMS! So its nice and happy pumping all this air spinning super fast. Now you slam the door on its face (close the throttle), the air that it pumped has to go somewhere right? Well it does, it backs up causing the turbo to spool down. Now when you open the door again, the turbo has spooled down and you have to wait for it to spool back up, this is where you feel this initial hesitation.
Now, the factory surgevalve(its not a bov) is very small and its located right at the begining of the system. So when it opens it vents the air that the turbo is pumping back into thr inlet of the turbo but you still have air thats already down the full stream at the throttle body. This air backs up so the small factory bov needs to vent the air pumping from teh turbo as well as the air thats coming back that was downstream already.
A larger bov aids in this. One bov can do it if its large enough, two do it even better.
NOW WHEN YOU RAISE YOUR BOOST, YOU HAVE MORE VOLUME USUALY, SO THE MORE VOLUME YOU HAVE, THE SMALLER YOUR FACTORY SURGE VALVE LOOKS!
SO yes you get better 1/4mile times but your HP does not go up.
THEN AGAIN, FROM EXPERIENCE, 99.9% OF THE PEOPLE PUT A BOV ON FOR THE SOUND AND NOT PERFORMANCE BECAUSE MY LOCAL AND NET CUSTOMERS USUALY CANT TELL ME WHAT A BOV IS REALLY FOR BESIDES SAYING "TO PREVENT TURBO SURGE."
When I ask them if they notice how the car recovers sooner, they tend to go huh? lol
Hope this helps.
Want to try it for your self? put a check valve on the factory surge valve so it does not open. RUn it and shift like you stole it. YOu will see the bigger hesitation after the shift.
ORIGINAL QUESTION:
No, our car has a MAP sensor which is speed density system. Look on top of hte manifold and you will see a pressure sensor. The ECU uses this pressure, as well as the sensor at the cold side pipe (inlet temp sensor) to determin MASS. So TEMP + PRESSURE = MASS. + means you putting them together, not adding them. So 90dege + 10psi does not = mass.
You get my drift.
Happy boosting!
Last edited by Exhaust Depot : 03-18-2007 at 05:36 PM.
The turbo can spool up to 100k RPMS! So its nice and happy pumping all this air spinning super fast. Now you slam the door on its face (close the throttle), the air that it pumped has to go somewhere right? Well it does, it backs up causing the turbo to spool down. Now when you open the door again, the turbo has spooled down and you have to wait for it to spool back up, this is where you feel this initial hesitation.
Now, the factory surgevalve(its not a bov) is very small and its located right at the begining of the system. So when it opens it vents the air that the turbo is pumping back into thr inlet of the turbo but you still have air thats already down the full stream at the throttle body. This air backs up so the small factory bov needs to vent the air pumping from teh turbo as well as the air thats coming back that was downstream already.
A larger bov aids in this. One bov can do it if its large enough, two do it even better.
NOW WHEN YOU RAISE YOUR BOOST, YOU HAVE MORE VOLUME USUALY, SO THE MORE VOLUME YOU HAVE, THE SMALLER YOUR FACTORY SURGE VALVE LOOKS!
SO yes you get better 1/4mile times but your HP does not go up.
THEN AGAIN, FROM EXPERIENCE, 99.9% OF THE PEOPLE PUT A BOV ON FOR THE SOUND AND NOT PERFORMANCE BECAUSE MY LOCAL AND NET CUSTOMERS USUALY CANT TELL ME WHAT A BOV IS REALLY FOR BESIDES SAYING "TO PREVENT TURBO SURGE."
When I ask them if they notice how the car recovers sooner, they tend to go huh? lol
Hope this helps.
Want to try it for your self? put a check valve on the factory surge valve so it does not open. RUn it and shift like you stole it. YOu will see the bigger hesitation after the shift.
ORIGINAL QUESTION:
No, our car has a MAP sensor which is speed density system. Look on top of hte manifold and you will see a pressure sensor. The ECU uses this pressure, as well as the sensor at the cold side pipe (inlet temp sensor) to determin MASS. So TEMP + PRESSURE = MASS. + means you putting them together, not adding them. So 90dege + 10psi does not = mass.
I think he was reflecting that you pointed out that this is how the BOV works (and whole turbo system too!), and was agreeing with you!
So, ED, how are we coming along on the charge pipes? Are we about ready?
Looking forward to doing some business...
Ciao dood!
You guys are killing me! Right now its 3am and i just finished working on an MD-88. Sooo i get off my passionate job at 730 am. So i have to find time to make it to the machine shop today!! This means no sleep for me today and i have to be at work at 930pm tomorrow.
Screw it! Ill go to the machinest tomorrow anyways!
I will do my best to bang this out for you guys by friday!
You guys are killing me! Right now its 3am and i just finished working on an MD-88. Sooo i get off my passionate job at 730 am. So i have to find time to make it to the machine shop today!! This means no sleep for me today and i have to be at work at 930pm tomorrow.
Screw it! Ill go to the machinest tomorrow anyways!
I will do my best to bang this out for you guys by friday!
Booyaa!
You ROCK dood! But, don't sacrifice your health just to get these done yet, take an extra day if you need to!
Some of us appreciate that you do this on your own time, and will support you in your efforts!
If you need any distance support, just let me know! I realize that I'm quite a ways away, but I'd be more than happy to do test fits, test trials, feedback, etc. (I used to be in Test Engineering and ran the Test Fabrication shop at a tier 2 supplier for Boeing, and tier 1 for Airbus/Grumman/Lockheed/Honeywell/etc., so I have a bit of a background for experimentation and testing with documentation!)
Later!
Paul
__________________
Her name is Roxy!
Mods:
Removed front plate
Kappasphere CAI
Exhaust Depot intercooler pipes
Lil' Chromies
Kappapouches
Kappabrella
"NON SIBI SED PATRIAE" ("Not for Self but for Country") - Cicero
~~~~~~~~~~~~~~~~~~~ Pontiac builds excitement... Saturn has rethought it's image...
The time has come for the enthusiasts... NASSOA
Founding Member - Recording Secretary - Northeast ~~~~~~~~~~~~~~~~~~~
[quote=73sbVert;463607]You ROCK dood! But, don't sacrifice your health just to get these done yet, take an extra day if you need to!
Some of us appreciate that you do this on your own time, and will support you in your efforts!
Agree...You're doing great for us. Just take your time and let us know when you are ready.
One question...Will you make a BOV available from you with the pipes so we do not have to go to multiple venders?
