BOV causing bad MPG?

[240dreams]

I just installed my Blitz SS BOV and im venting. I get the "almost stalling after full boost" crap. Before i installed the bov i got 250 mpt now i get like 200mpt. can this be the reason?

[IvoryJ30t]

if your venting to atmosphere, and doing alot of around town driving, then yes.

when the car wants to stall, its because your venting metered air. the ecu doesnt know the air is missing, and tries to add fuel for that air. makes the car rich, and bog, which is what the almost stalling is.

[240dreams]

damn. i thought so. hmm good gas or great sound? im in a dilemma.

[IvoryJ30t]

yeah, every time you vent air out of the BOV, your injecting more fuel than you need to. if you were able to recirculate it, you would regain some MPG, but you will lose BOV volume.

[silva180sx1515]

i think drivablility is more important, but that's just me

[dj_lennon_franz]

doesnt an AFC fix this problem?? or is it a VPC??

[nnkfws333]

I believe AFC fixes it.

[240SXer]

How would the AFC fix it?

[nnkfws333]

well with an SAFC2 you can adjust the fuel curve and blah blah heres the info from Apexi website

Quote »The second-generation S-AFC is a fuel computer that adjusts fuel/air ratio by modifying the air-flow meter/MAP sensor signal. The S-AFC features a user-definable, eight-point, adjustable fuel curve that can be set in 500 RPM increments. The range of fuel adjustment is +/- 50% at each of the user-defined setting points. On hot-wire vehicles, the Deceleration Air Flow Correction function is capable of curing the erratic idle and stall problems associated with open-atmosphere blow-off valves on hot-wire air-flow meter systems. [/quote]

[IvoryJ30t]

the e-manage has anti-stall also.

[ride4lame]

You want something like a Power FC djetro...basically anything that converts the mafs system to map.In my opinion you should just reicirculate. I am venting right now and it hurts performance. You bog after shifts and it slows you down...

[IvoryJ30t]

or you can fab up a blow-thru MAF setup on the cold pipe, and place the BOV on the hot pipe.

[ride4lame]

or you can fab up a blow-thru MAF setup on the cold pipe, and place the BOV on the hot pipe.

You can. but then you often run into problems with poor metering, to much heat frying the mafs, and oil ruining the mafs.Its not an extremely reliable setup. PLus mafs are usually smaller so it puts a 'kink' in the larger piping

[IvoryJ30t]

without a catch can, it may foul the MAF, but with some tuning [safc, ect...] it works out nicely. has to be on the coldpipe, saves it from too much heat. also, its less of a restriction on the pressure side than it is on the atmospere side of the turbo. air under pressure will flow through a restriction much easier than air under vacuum.

[IvoryJ30t]

notice how the intake of a turbo is usually much larger than the output.

[240SXer]

How can I vent my typeS internally?

[ride4lame]

How can I vent my typeS internally?

vent internally?i guess what you mean is recirculateYou will run a hose from the outlet, and run it into the turbo inlet(ie intake pipe), inbetween the mafs and the turbo.

[240SXer]

I guess I've gotta get somthing welded on the intake pipe to accept the hose. Anyone have pix of a setup?

[layzienoy]

i have a open atmosphere BOV in my car and it used to cause a bunch of problems with stalling and idling funny when you satrt it on cold days, but I got a SAFC2 installed and adjusted it myself and solved the problem for the most part evry now and then it gets pissy on cold days

i was planning on getting the SAFC anyways and it solved my problem soo all the better

and the tuning of the SFAC2 isn't that hard to deal with when adjusting for the BOV, its under the Dec. Air blah blah blah