Hey Guys,

I was thinking about unplugging the redirecting tubes off my factory BOVs and letting them vent to atmosphere because I really like the sound of a BOV. I'd then just plug the other end of the tubes of course so I don't have an intake leak.

Now I know these are MAF cars and right as the BOV opens on a shift it would be blowing out metered air causing a momentary rich spike. That shouldn't hurt anything right? Or is there a downside I'm not thinking of?

Thanks
Malcolm

 

Im tuned for Mafless and considered trying this today as well. I also would like some feedback if anyone has used their oem DVs to vent to atmosphere.

 

The car counts on the re-circulated air. So unless MAFless it will through a cel. You could do it to try and see if you like it. Won't hurt anything. Then get some billet BOV's for added effect.

What tune do you have?

 

The spike won't "hurt" anything per say but I don't think its worth it.

I ran my Forge DV's to atmosphere for a while on my mafless setup before changing over to Tial BOV's. Nice sound but def prefer the Tial BOV's.......

 

Did not know about it throwing a CEL. Markski tuned the car. I noticed a lot of guys go MAF less. I assume you can adjust the tune to just use the MAP sensor with pre-programmed tables and delete the MAF sensor. Are there any downsides? drivability or anything like that?

 

So I did this on my Cayenne turbo without a tune, however, I recirc'd them back into the turbo intakes, post MAF. Believe me you can still hear them even if you did it this way!!! Drive-ability was great too. If were to vent them to atmosphere, you could possibly have some stalling and CEL as said before.

If I was going to do this...I would also dump the stock air intake, run fender intakes and get a MAF-less tune. It starts to get more involved at this point. But would be fun project.

 

So today I plugged my intake, and set the oem dvs to vent to atmosphere, as I am tuned mafless. It is pretty cool sounding, but kind of loud. For sh*ts and grins, I loaded my MAF tune and plugged in my MAF sensor, Went for a ride and did some logs. Long story short, my dash lit up like a Christmas tree! Moral of the story, if your not tuned mafless, do not vent 100% to atmosphere. Car runs like dog sh*t, and throws lots of codes.

 

Cant do it on a maf... I would not go mafless either... drivability goes away.. Ive heard it from many guys....

 

thats complete bs. protomotive has been doing mafless tunes for yrs. i have been in more than a few. no way to tell from a maf file as far as driveability.

 

Furthest thing from the truth no offense. The only thing I have noticed with extremely ported heads you will get a little delayed response in drivability. Otherwise my car drives like stock especially with the 3.9L.

 

4 of my clients dropped mafless and went back to running a oem MAF... ALL 4 are on here... one is Erik, Hector is PR with A30rs, another is Ken, etc... Im not making this up... Ive been around P cars for a many years, I don't know everything but I do know what I know.... my opinion is subjective of course and everyone is entitled to it... Steve, I can give you 3 emails you can contact them, then come back and maybe tell us what they say. Mind you, they started with maf tunes, went to mafless, and then went back... have you ever run mafless on a stock ecu? I doubt it... you went from epl to proefi. I've went thru many cars... I had mafless on mine many moons ago...
It's not for everyone... some really do NOT like it... and thats a subjective opinion not a fact... yet you of all people never had mafless on a stock ecu( other then sitting in a few ) and make it sound like you know the absolute answer. I'm sorry but I disagree with you... and thats Ok too...
markski

 

I switched from maf to mafless from 911tuning to protomotive mafless tune and my car run like **** if you would ask me idle high as hell 1700rpm and I have twin hks bov too

 

Somethings wrong with your car then. My car idles at 900rpm once warm as if it was stock........I doubt you had a protomotive tune then, or some real **** injectors.......

 

Stock ECU, Mafless, Protomotive, E85.......the video was just to show the sound of the exhaust and then idle.....

 

My 2 cents on the MAF and MAF-less setups. I've never tuned a Porsche but I have tuned other MAP and MAF based cars and take it the concepts are similar.

When I turned my turbo Honda myself, MAF-less setup that used a MAP sensor, I had to populate a lot of tables and it took some time. Load vs RPM etc. You have to populate all the values for all the possible configurations.

Then you have to tweak and configure sub tables that take into account air temp changes because air density varies with temp as much as it does with pressure. I found myself constantly tweaking and fine tuning this setup in the 2+ years I daily drove it. Especially when the weather had huge swings in temps things would be off a little till I could adjust the tables for those temps etc.

My supercharged Mustang on the other hand is a MAF setup, also tuned myself, and it's a dream to tune by comparison. The MAF sensor takes into account air density by temperature and there's no tweaking. It simply tells you the volume of air going in period. No ifs ands or buts about it.

So I can see where a MAF setup runs very smooth in nature and a MAF-less setup requires a lot of work to have the tables just perfect and could indeed present drivability issues if not done right.

Just my experience on different cars.... same concepts so I imagine the logic is not to far off when applied here.