imported_LiL Devil

The downside of releasing the air to atmosphere vai BOV is that it has already been metered by the mass air sensor (MAS), and when it blows off the ECU will be injecting the wrong amount of fuel into the cylinders.(The MAS reads ten air units, say, and the ECU tells the injectors to squirt the right amount of fuel for ten air units.But then five of those air units are vented off to atmosphere, and only five make it to the cylinders, and five more have to be drawn from the outside air, through the MAS again) so the engine temporarily runs extremely rich, meaning too much fuel is injected into the cylinders.

This temporary rich condition isn't usually that harmful, but it can cause bucking or hesitation on lift-throttle

I don't understand this because if the throttle plate is close even with a CBV the exrta air is draw back to the turbo and back to the engien it won't go in cuz the throlle is not open. so why would venting the air out with a BOV causing bucking at lift throttle?

imported_ERTW

civics do not have mass air flow sensors.

also, the released air does not magically go straightback into the turbo through your engine bay.

the blow off valve is also usually installed before any air metering takes place, (it is illegal to dump air back into the atmosphere once it has already been accounted for by the ecu)

HamiltonsIsuzu

yeah, hondas dont have maf's to my knoledge, well ive never seen one.

Drewspeed

Cars that use MAF's benefit greatly from recirculating kits made for BOV's that release into the air. I know HKS makes one (or was it custom) for their SSQV.....

You don't get the fancy noise but that rich running condition/probable stalling issue is averted I believe.

Let me look for a pic....

imported_LiL Devil

OKay let say the car have a MAF. So BOV vent the air but it will make the car run rich becasue the MAF already account but it's not there cuz it's in the air But the other kind that redirect the air back to the intake would it also make the car run rich as well becasue the tthrottle plate is close so the air wouldn't go in but the fuel is still ther for that amount of air

CaptHowdy

MAF's usually come right after the filter. they don't account for pressure so simply relocating it after the BOV won't work.

MAPs (what all (from what I know) honda's have) is in the intake manifold and can factor in pressure (boost).

if you have a MAP sensor you can recirc/vent with no ill effects.

MAFs if you vent you're releasing metered air (not to mention if you have a crappy BOV it will most likely leak) and more often than not the car drives like junk. it will also noticeably effect your gas mileage.

the trick is if you have MAF and want to vent is to convert it to a MAP instead, DSM's usually go for the GM air meters w/ a transaltor and position it AFTER the BOV close to the tb.

now to vent or not to vent? that is the question

recirculating keeps the boosted air in but it also makes it difficult for the turbo to start spooling again because of all the pressure in the intake track (the turbo is basically being pushed from both sides so it has a hard time moving)

if you vent all the negative pressure in the intake lets it spool freely (now your exhaust is pushing and your intake is pulling!) and it goes PSSSST which gets all the chicks.