Mitsubishi controls boost w LEAKY bov? what next?
Mar 1, 2010, 03:24 PM
#1
Mitsubishi controls boost w LEAKY bov? what next?
so i decide to vent my stock bov to atmos. everything was going good so far, i was happy i got rid of bov hose which i hated.
so u got on the car to check sound ect. and i notice that i would hear a rush of air at about 4k...then repeatly i kept hearing it in every gear...and i thought to myself "dont tell me this bov is leaking under boost".
so i get someone to hold the pedal to about 3k nothing then 4k ......suddenly a rush of air then at 5k it almost went away...then i wondered to myself this is stupid..
i had a greddy bov in my garage i get it and install it and wow no more air. then i go for a ride and i step on it instantly i notice car was faster. come to find out im hitting 27-28lbs in first gear(still tapers) 2nd gear i hit 32lbs and i get cel i automatically knew it was overboost.
i put the old bov and i got the same results. do the stock bov's puposly leak to helpcontrol boost.. from what is going on it def seems so. is this common?
now what should i do how can i control my boost?
p.s sorry for grammar rushing
so u got on the car to check sound ect. and i notice that i would hear a rush of air at about 4k...then repeatly i kept hearing it in every gear...and i thought to myself "dont tell me this bov is leaking under boost".
so i get someone to hold the pedal to about 3k nothing then 4k ......suddenly a rush of air then at 5k it almost went away...then i wondered to myself this is stupid..
i had a greddy bov in my garage i get it and install it and wow no more air. then i go for a ride and i step on it instantly i notice car was faster. come to find out im hitting 27-28lbs in first gear(still tapers) 2nd gear i hit 32lbs and i get cel i automatically knew it was overboost.
i put the old bov and i got the same results. do the stock bov's puposly leak to helpcontrol boost.. from what is going on it def seems so. is this common?
now what should i do how can i control my boost?
p.s sorry for grammar rushing
Mar 1, 2010, 04:00 PM
#2
You've got it kind of wrong...
Yes the stock diverter valve is leaky... but it's a closed MAF based system so it's metering the air coming out to work the system correctly.
Yes the stock diverter valve is leaky... but it's a closed MAF based system so it's metering the air coming out to work the system correctly.
The ECU meters incoming air via the MAF, and using inputs from the MAF, TPS, MAP (if so equipped), RPM, O2 sensor(s) and who knows what else determines how long to fire the injectors. If any of that metered volume of air is vented to atmosphere, the ECU has no idea that it's lost some air and will fire the injectors long enough to match the volume or pre-metered air. Result? Rich condition.
And just for a minute, consider what happens a non-recirculated valve is open during normal driving. When not making boost, turbocharged motors live in vacuum. Maybe even enough vacuum to hold the BOV/DV open. Ingesting unmetered, and in 99% of the cases which I've seen, unfiltered air. Sound like a good idea?
And just for a minute, consider what happens a non-recirculated valve is open during normal driving. When not making boost, turbocharged motors live in vacuum. Maybe even enough vacuum to hold the BOV/DV open. Ingesting unmetered, and in 99% of the cases which I've seen, unfiltered air. Sound like a good idea?
Mar 1, 2010, 05:28 PM
#4
The best way to control boost (AFRs, timing, MIVEC, et al) is to have the car professionally tuned. Search around in the Dyno forum or your Regional forum to find someone near you who's qualified to do it. I know there are some good tuners in the Northeast (heard good things about IveyTune,) just make sure to do your homework as not all tuners are equal.
Mar 1, 2010, 05:40 PM
#5
so i decide to vent my stock bov to atmos. everything was going good so far, i was happy i got rid of bov hose which i hated.
so u got on the car to check sound ect. and i notice that i would hear a rush of air at about 4k...then repeatly i kept hearing it in every gear...and i thought to myself "dont tell me this bov is leaking under boost".
so i get someone to hold the pedal to about 3k nothing then 4k ......suddenly a rush of air then at 5k it almost went away...then i wondered to myself this is stupid..
i had a greddy bov in my garage i get it and install it and wow no more air. then i go for a ride and i step on it instantly i notice car was faster. come to find out im hitting 27-28lbs in first gear(still tapers) 2nd gear i hit 32lbs and i get cel i automatically knew it was overboost.
i put the old bov and i got the same results. do the stock bov's puposly leak to helpcontrol boost.. from what is going on it def seems so. is this common?
now what should i do how can i control my boost?
p.s sorry for grammar rushing
so u got on the car to check sound ect. and i notice that i would hear a rush of air at about 4k...then repeatly i kept hearing it in every gear...and i thought to myself "dont tell me this bov is leaking under boost".
so i get someone to hold the pedal to about 3k nothing then 4k ......suddenly a rush of air then at 5k it almost went away...then i wondered to myself this is stupid..
i had a greddy bov in my garage i get it and install it and wow no more air. then i go for a ride and i step on it instantly i notice car was faster. come to find out im hitting 27-28lbs in first gear(still tapers) 2nd gear i hit 32lbs and i get cel i automatically knew it was overboost.
i put the old bov and i got the same results. do the stock bov's puposly leak to helpcontrol boost.. from what is going on it def seems so. is this common?
now what should i do how can i control my boost?
p.s sorry for grammar rushing
Mar 1, 2010, 05:40 PM
#6
car is already tuned. my problem here isnt about tuning. its really about controlling boost. boost is currently ecu controlled(stock boost). my next question is if i remove all boost pills and use a boost controller will i gain control over boost again?
Mar 1, 2010, 05:51 PM
#9
If you remove the pill closest to the compressor you'll be running wastegate pressure, which is ~12psi with the stock WGA.
The pills nearest the boost solenoids help mitigate pressure spikes, so you'll probably want to leave those intact for now.
Mar 1, 2010, 05:54 PM
#10
no, you aren't losing control. Going to a MBC or EBC nets you nothing.
The airflow system is basically closed and by dumping it to the air you're not allowing the ECU to compensate for the expected air coming out of the diverter valve back into the LICP so you get all sorts of wild *** fluctuation.
This is NOT a new "problem" as the same setup has been used for the 8 and 9 (the X valve is the same as the 9 valve). I suggest you search for BOV VTA in the 8/9 forums to see 7 years of posts regarding the subject.
The airflow system is basically closed and by dumping it to the air you're not allowing the ECU to compensate for the expected air coming out of the diverter valve back into the LICP so you get all sorts of wild *** fluctuation.
This is NOT a new "problem" as the same setup has been used for the 8 and 9 (the X valve is the same as the 9 valve). I suggest you search for BOV VTA in the 8/9 forums to see 7 years of posts regarding the subject.
Mar 1, 2010, 07:16 PM
#13
Boost is controlled by the factory ECU. If you want to run this new valve and it's causing boost spikes as high as you're reporting then you need to have the car re-tuned.
If you remove the pill closest to the compressor you'll be running wastegate pressure, which is ~12psi with the stock WGA.
The pills nearest the boost solenoids help mitigate pressure spikes, so you'll probably want to leave those intact for now.
If you remove the pill closest to the compressor you'll be running wastegate pressure, which is ~12psi with the stock WGA.
The pills nearest the boost solenoids help mitigate pressure spikes, so you'll probably want to leave those intact for now.
thanks
Mar 1, 2010, 07:23 PM
#14
no, you aren't losing control. Going to a MBC or EBC nets you nothing.
The airflow system is basically closed and by dumping it to the air you're not allowing the ECU to compensate for the expected air coming out of the diverter valve back into the LICP so you get all sorts of wild *** fluctuation.
This is NOT a new "problem" as the same setup has been used for the 8 and 9 (the X valve is the same as the 9 valve). I suggest you search for BOV VTA in the 8/9 forums to see 7 years of posts regarding the subject.
The airflow system is basically closed and by dumping it to the air you're not allowing the ECU to compensate for the expected air coming out of the diverter valve back into the LICP so you get all sorts of wild *** fluctuation.
This is NOT a new "problem" as the same setup has been used for the 8 and 9 (the X valve is the same as the 9 valve). I suggest you search for BOV VTA in the 8/9 forums to see 7 years of posts regarding the subject.
i was under impression the pills were not working how they should. cause like you said ecu cant compensate.
through me doing this i learned that the stock bov DOES leak under boost. i guess like you said its designed to but i WONDER why? because
1. if i vent the stock bov to atmos. = boost is perfect
vs
2. if i use aftermarket bov to atmos.= over boost
only difference is that the one that LEAKS controls boost
like how it should
btw i dont get any fluctuations w aftermarket bov, but i do with stock its weird
i think the stock bov may leak at idle also but very minimal
