Blow off Valve???
Blow off Valve???
Senior Member
Joined: 10-30-07
Posts: 1,457
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From: Bakersfiled,CA
Well they still really haven't made any aftermarket bov's but u can still put one on your car
like i did
http://www.youtube.com/watch?v=8OtZI7_QVZA
like i did
http://www.youtube.com/watch?v=8OtZI7_QVZA
Senior Member
Joined: 05-14-08
Posts: 1,023
Likes: 1
From: around the world
The srt4 didn't have a maf sensor so venting the bov was ok unlike our cars, gm isn't going to release a bov kit that vents and possibly screws up maf calculations.
everyone loves a ping sound.
Senior Member
Joined: 07-25-08
Posts: 12,450
Likes: 6
From: Florida
It can cause rich codes that you cannot tune out because it will happen when the BOV vents. You have to recirculate the BOV back into the intake post MAF so you dont cause driveability issues and power loss.
To me the blow off valve is pointless. i have the Hahn Charge piping, and Hahn Intake and with those you can really hear the recirc. I am also tuned and all the extra boost makes it hella loud! ill go under a bridge in second gear, lay on it and let off and man is it effing loud!! i had some guy ask me if i had an engine swap in my car. lol! all a blow off valve will do is make a noise, no performance help at all. imo wast of money.
Premium Member
Joined: 04-12-09
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From: Madison, Ohio
I have a bov, but i am havin issues w/ the comp. i will start my car drive it, and will get 3 to 5 psi after driving it for atleast 10 to 15 minutes. the more i romp on it the sooner it happens. then if i pull over, shut the car off start it right back up and holy **** batman back to 15 psi this is drivin me nuts, the car is quick then goes limp (lol ) and i am a wounded animal in the woods waitin to get taken out by a honda hahaha. any if ya have any ideas pls comment or pm me. i am runnin outa thought, its also a knock off 50 dollar brand new xs power type h replica of the turboxs type h model. that and not pos. what size flange he put on but its stated they r tested at 30psi so i didnt see it being an issue. i know he installed it on the passenger side pipe coming off the front mount and also after the sensor he went steel piping an welded the bov there that way he could avoid the sensor so it was nvr tampered with, also used t-bolt clamps to hold pressure to stock plastic to steel.
Last edited by KnightSS/TC; Jul 18, 2009 at 05:44 PM. Reason: left somthing out
Senior Member
Joined: 06-28-08
Posts: 2,585
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From: Clarksville
To me the blow off valve is pointless. i have the Hahn Charge piping, and Hahn Intake and with those you can really hear the recirc. I am also tuned and all the extra boost makes it hella loud! ill go under a bridge in second gear, lay on it and let off and man is it effing loud!! i had some guy ask me if i had an engine swap in my car. lol! all a blow off valve will do is make a noise, no performance help at all. imo wast of money.
Banned
Joined: 02-19-09
Posts: 3,818
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From: Carol Stream
really the only way i see a bov working is to move the maf sensor. im going to be trying this in 2 weeks when i get some free time and then retune my car and go from there if it works i will be talking with vendors to get something out for those who want it. so ill let you know how everything goes.
Yeah thats my plan too! im looking at just doing a K04 and trying to squeeze 400hp out of it. thats my main hp goal.
Senior Member
Joined: 09-28-08
Posts: 588
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From: Long Island
I have a bov and pual, BCP tuned it nasty and the guy who installed my setup did a great job with the maf sensor, the car runs great and I don't see powerloss on dynos, infact paul tuned it to be a beast! I also plan on going big turbo soon but want to wait till fueling is figured out! once that happens then there will be a wonderfull new shiny turbo on my car lol
I have a bov and pual, BCP tuned it nasty and the guy who installed my setup did a great job with the maf sensor, the car runs great and I don't see powerloss on dynos, infact paul tuned it to be a beast! I also plan on going big turbo soon but want to wait till fueling is figured out! once that happens then there will be a wonderfull new shiny turbo on my car lol
Senior Member
Joined: 02-09-09
Posts: 4,374
Likes: 5
From: Tejas
I have a bov, but i am havin issues w/ the comp. i will start my car drive it, and will get 3 to 5 psi after driving it for atleast 10 to 15 minutes. the more i romp on it the sooner it happens. then if i pull over, shut the car off start it right back up and holy **** batman back to 15 psi this is drivin me nuts, the car is quick then goes limp (lol ) and i am a wounded animal in the woods waitin to get taken out by a honda hahaha. any if ya have any ideas pls comment or pm me. i am runnin outa thought, its also a knock off 50 dollar brand new xs power type h replica of the turboxs type h model. that and not pos. what size flange he put on but its stated they r tested at 30psi so i didnt see it being an issue. i know he installed it on the passenger side pipe coming off the front mount and also after the sensor he went steel piping an welded the bov there that way he could avoid the sensor so it was nvr tampered with, also used t-bolt clamps to hold pressure to stock plastic to steel.
Does the following quote sound familiar? In short, your BOV could be causing a rich condition due to the system losing air each time and causing the car to go into a kind of protective limp mode.
Most of the time if your seeing P0101 (cruise fuel trim rich) codes after you have installed a new intake and have insured there are no leaks it is being caused by fine oil mist from the filter contaminating the MAF sensor. (usually takes about a week or two for the issue to raise its ugly head) Once its contaminated it is almost impossible to make the MAF work right again. I had this issue for a while after I put my CAI on last year. Once I changed the MAF the issue went away and never came back again. However at the same time I went to a dry flow non oiled filter.
You can spray the maff out with electrical cleaner or brake clean until the cows come home and it will fix it for a day but the issue comes right back. What I'm saying is in most cases its not really the fault of the CAI its the fault of the filter attached to it contaminating the MAF.
It also requires the fault to set 2 consecutive times to throw a code. If it sets just once during a key cycle it controls wastegate wide open and the boost drops to 2 to 5 LBS until the next key cycle.(the ECM goes into catalytic converter engine protection mode) The first time it sets you wont see a code but you'll be scratching your head wondering why the boost just went away all the sudden.
If your setting P0101's monitor the cruise fuel trim(LTFT) while driving 20 or 30 miles at light throttle. If the LTFT's continue to fall and go below -25 it will trip the code the first time. -25 is the P0101 threshold in the diagnostic algorithm. The part that is odd is if you watch it in real time you usually won't see above -15. Sometimes this is caused by to slow of an update rate of the tool you are using to monitor the data with. If you do a real time capture you will find the value is quite different at times than real time monitoring.
The same thing can happen with a K&N drop in.
You can spray the maff out with electrical cleaner or brake clean until the cows come home and it will fix it for a day but the issue comes right back. What I'm saying is in most cases its not really the fault of the CAI its the fault of the filter attached to it contaminating the MAF.
It also requires the fault to set 2 consecutive times to throw a code. If it sets just once during a key cycle it controls wastegate wide open and the boost drops to 2 to 5 LBS until the next key cycle.(the ECM goes into catalytic converter engine protection mode) The first time it sets you wont see a code but you'll be scratching your head wondering why the boost just went away all the sudden.
If your setting P0101's monitor the cruise fuel trim(LTFT) while driving 20 or 30 miles at light throttle. If the LTFT's continue to fall and go below -25 it will trip the code the first time. -25 is the P0101 threshold in the diagnostic algorithm. The part that is odd is if you watch it in real time you usually won't see above -15. Sometimes this is caused by to slow of an update rate of the tool you are using to monitor the data with. If you do a real time capture you will find the value is quite different at times than real time monitoring.
The same thing can happen with a K&N drop in.
That came from this thread: https://www.cobaltss.net/forums/2-0l-lnf-performance-tech-153/limp-mode-dejon-intake-178779/
A few others have reported similar issues which may be like the example above.
Last edited by Stamina; Jul 19, 2009 at 12:25 AM.
Senior Member
Joined: 06-28-08
Posts: 2,585
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From: Clarksville
Dont our cars have a K04 twin scroll stock? Either way I'm gonna wait a year or 2 and yank off the Brembos, run slicks, as much weight reduction as possible, full bolt ons and see what I can run like that. And then a year or 2 after that build the motor and run a huge turbo. Atleast that is what my dream was about, LOL!!
