Blow Off Valve

[v-mac]

i was about to install my turbo xs rfl that i had bought, and was int he process of buying the maft and gm maf...before i bought the maft and maf i ran across a guy that has worked at a mitsubishi dealership for over twenty years as a mechanic...i was running somethings by him telling him what i was planning on doing and he said that buying the maft and maf were pointless, that the performance wasnt exactly what i was lead to believe...instead eh told me to save my money and to un hook the pipe that runs from the stock BOV to the intake...i unbolted the side attatched to the intake and let her rip at 3500 and it sounded loud as hell! but i was always made aware that venting without the maft and maf was going to messs up my car and make it run funny...this guy says it has no negative effect on the car, i believe him because hes been working on these cars and knows literally everything their is to know about the turbo'd dsms...just wanted tor un this by people and see what you thought?...ive had no problems whatsoever and since this guy is a family friend i knwo he wouldnt tell me to do somethign that would jepordize the performance of my car

 

[Dsmj89]

Wow, GRAMMAR GRAMMAR GRAMMAR! Next, as cool or nice the bov may sound, i would recommend recirculating your bov. It is not worth the noise and sooner or later it would start causing problems. As of now you are running rich between shifts and that's a no no to start. Recirculate and save future headaches.

 

[92tsiawdguy]

Youre dumping metered air out of the car so its adding extra fuel.

 

[Leitnin]

"worked at a mitsubishi dealership"

Humbly asking, what does working at a dealership have to do with knowledge about modding cars? I'm sure some guys that work at dealerships are into cars and may mod their own or others for fun just like the rest of us, but training has he gotten as it relates to modifying a DSM? I doubt they teach them about things like recirculating vs venting. (if they did, he would know venting is a pretty poor idea).

Other guys at dealerships have probably never modded a car in their lives. They fix things, they replace things, etc. That doesn't mean they know about air fuel tables, how the ecu calculates airflow, the process the ecu uses to determine how much fuel to add, etc.

His advice basically equates to 'don't bother trying to control your air metering in a different way, just dump metered air to the atmosphere and run rich, because the louder sound = better performance'

Bottom line, as its been said countless times. The air coming in gets counted. An amount of fuel is determined to power the car based on that amount of air. You are throwing a bunch of that air out of the system (for no real benefit other than increasing the volume of your BOV) and screwing up your air/fuel ratio.

Running rich isn't good for performance.

Do more research, learn how all this stuff works. Use punctuation, and then make your decision.

 

[chico904]

Kick that guy square in the nuts...twice.
If you are going to do it right, then by all means go for it, but if not, please do not do it.
No but seriously, think of it this way. Your car is expecting "x" amount of air to mix with the fuel. With that mixture, your car is happy and runs fine. Instead you are taking that air that your car is waiting for, and "giving" it away to the atmosphere. Your car does not like what it expected to get given away to someone else. You just gained a friend by giving the gift of air to the atmosphere, and everyone within earshot will know it. The friend you gained is what some call a "ricer" However, you just made an enemy,your car, and she will let you know it. She will run rich, run rich between shifts, possibly bog down, and possibly have trouble idling. So pick which friend you want to keep happy....

 

[4G63gst1990]

i second the kicking in the nuts i did what he told you to do when i first bought my car and it didnt take me but to seconds to smell the fact that i was running way rich so i stopped and put the recirulating hose back on and no more running rich smell but yes it does sound cool just get the maft and maf and do it right

 

[Drifte]

Not wanting to start a flame war ...but. The car measures the air coming through the maf. If your bov is not recirculated it could be leaking at idle. If your intake is capped off and your bov doesnt leak it would probably run fine. When I bought my car it came that way. Ran just fine actually, now with a different bov it wants to die between shifts, because this bov leaks. Is it worth it to vent? No, but for now I dont have a choice. You have the choice to do it the right way now if you want. The turbo xs rfl is not the bov I would go for anyway.

 

[chico904]

Not wanting to start a flame war ...but. The car measures the air coming through the maf. If your bov is not recirculated it could be leaking at idle. If your intake is capped off and your bov doesnt leak it would probably run fine. When I bought my car it came that way. Ran just fine actually, now with a different bov it wants to die between shifts, because this bov leaks. Is it worth it to vent? No, but for now I dont have a choice. You have the choice to do it the right way now if you want. The turbo xs rfl is not the bov I would go for anyway.

Yes forgot to add that the turbo xs RFl is highly prone to leaking. If I were you I would ...

1. Save the money you were going to use to vent it properly, if you were..
2. Sell that BOV
3. Buy a 1G BOV
4. Recirculate

 

[JusMX141]

i was about to install my turbo xs rfl that i had bought, and was int he process of buying the maft and gm maf...before i bought the maft and maf i ran across a guy that has worked at a mitsubishi dealership for over twenty years as a mechanic...i was running somethings by him telling him what i was planning on doing and he said that buying the maft and maf were pointless, that the performance wasnt exactly what i was lead to believe...instead eh told me to save my money and to un hook the pipe that runs from the stock BOV to the intake...i unbolted the side attatched to the intake and let her rip at 3500 and it sounded loud as hell! but i was always made aware that venting without the maft and maf was going to messs up my car and make it run funny...this guy says it has no negative effect on the car, i believe him because hes been working on these cars and knows literally everything their is to know about the turbo'd dsms...just wanted tor un this by people and see what you thought?...ive had no problems whatsoever and since this guy is a family friend i knwo he wouldnt tell me to do somethign that would jepordize the performance of my car

Right....because every Mitsu tech knows exactly what's best for our cars.

IF he truly is a Mitsu tech, he wouldn't have told you to vent your valve because he would know the adverse effects that it would cause. Honestly, I've never seen such a line of bullshit come out of a dealer tech's mouth, but then again I learn what I need to know from others who have the same car as me, and who have had the same experiences that I have....not someone that changes the spark plugs on one Eclipse then changes oil in three Diamante's, and is considered a "professional".

Why are you making your first mod a Translator and 3" GM MAS? Generally that's a good choice for someone who's close to overrunning the stock MAS.

If you think your BOV was loud when it was vented and you cut the throttle in neutral at 3500, you should hear a recirculated 1G BOV on a car running 30psi. If I live to be 100, I suppose I'll never understand why some folks enjoy amplifying the sound of the air that is being ejected from their intercooler piping everytime they shift. I prefer to call that sound annoying.

 

[Defiant]

The mechanic you spoke with was mistaken.

Search "venting" on this site, or perhaps try reading​

THE THIRD GODDAMNED STICKY IN THE FAQ LIST:
http://www.dsmtuners.com/forums/fre...tions/113858-venting-your-bov-atmosphere.html

Merry Christmas. ​