Souund of a blow off valve...

[fiveohwblow]

Sound of a blow off valve...

For a list of my mods, look at my sig. I am considering upping the boost via pulleys on my 5.0, but I am in dire need of either a blow off valve, or a bypass valve. I am aware of the functions for the most part, but my question is more of sound. I know with less than a 2 liter of mountain dew for an engine you can easily hear a blow off, but what about a genuine mustang with exhaust? Has anyone used both and prefer one over the other? Thanks for your help guys!

 

[RacEoHolic330]

Well, a lot of people are going to tell you that you need a blow-thru MAF meter to use a blow off valve, which is partially true. I have a greddy type RS bov that is vented to the atmosphere and im using a draw-thru maf. I have no driveability issues at all. When I shift the car goes rich for a fraction of a second and then its back to normal. It also goes rich when i downshift, but there are no stalling problems. The sound is soo amazing. It doesn't sound like those gay high pitch bov's on honda's. I swear, they sound like a baby is sneazing or something. Mine sounds like a loud swoosh of air. I've had people try to mess with me on the highway and when i rev my engine and they hear the BOV, they seem to have lost their want to race.

You just have to adjust the bov properly so it doesn't open up too easily and cause surging. UnderpressureGT has the same setup as me and he has no problems either.

 

[fiveohwblow]

Well, a lot of people are going to tell you that you need a blow-thru MAF meter to use a blow off valve, which is partially true. I have a greddy type RS bov that is vented to the atmosphere and im using a draw-thru maf. I have no driveability issues at all. When I shift the car goes rich for a fraction of a second and then its back to normal. It also goes rich when i downshift, but there are no stalling problems. The sound is soo amazing. It doesn't sound like those gay high pitch bov's on honda's. I swear, they sound like a baby is sneazing or something. Mine sounds like a loud swoosh of air. I've had people try to mess with me on the highway and when i rev my engine and they hear the BOV, they seem to have lost their want to race.

You just have to adjust the bov properly so it doesn't open up too easily and cause surging. UnderpressureGT has the same setup as me and he has no problems either.

Ok awesome. Thats some good info, and thank you. I saw the different MAF's advertised when I purchased mine, but was never explained the difference between the two. What exactly is the difference and what determines whether or not you need a draw-thru for a BOV? I assume it has to do with the direction of the sampling tube/electronics, but again I could be way off... Thanks agian.

 

[fiveohwblow]

Anyone? Any answers to my question about draw-thru???

 

[LukeDaddy]

What happens when you use a BOV that vents to the atmosphere with a draw through setup, is you are releasing air that has already been metered, and there has been fuel injected to account for this metered air... Hence what you are doing is causeing a rich condition every time the valve releases air... there are two ways of doing this...

You can use a valve that diverts the metered air back to the intake tract after the MAF... or you can use a blow through meter, and place the valve before the MAF...


Some ECUs have a function where you can tune this condition out between shifts.. but for the cheap way, do it one of the two ways I listed...


Luke

 

[RsStanG1987]

Look up underpressuregt i think he has one.

 

[Paul Perreca]

never even knew you'd need a BOV for a blower, thought that was just turbo's - not experienced

 

[fiveohwblow]

What happens when you use a BOV that vents to the atmosphere with a draw through setup, is you are releasing air that has already been metered, and there has been fuel injected to account for this metered air... Hence what you are doing is causeing a rich condition every time the valve releases air... there are two ways of doing this...

You can use a valve that diverts the metered air back to the intake tract after the MAF... or you can use a blow through meter, and place the valve before the MAF...


Some ECUs have a function where you can tune this condition out between shifts.. but for the cheap way, do it one of the two ways I listed...


Luke

Ok I get it. That makes perfect sense. I think I will call vortech just to check over a few more things. Do you know if SCT chips have that availability to tune this out, as I have already had one installed and custom tuned to my car. Thanks a bunch for the info!

 

[LukeDaddy]

I dont have a lot of experience with the SCT stuff, but Im sure they can work out something....Y/W for the info...someone had to teach me too at one point...


Luke