Does BOV affect air fuel ratio?

[greygirl1976]

was your engine standard if it was u had a fault somewhere in the electrical system mate ive put an rb20t in a silvia and it went through the nsw rta emmision laws with a bov venting to atmo and passed with flying colours my car has been on the dyno with a bov venting to atmo it passes emmision laws

and gijor33 o2 sensors r in use all the time what do u think helps control a.f ratios

[J.B.E]

where's the boxin gloves its all on in here,

gettin bak to helpin the poor guy with problem

[DAMQIK GTS-T]

Originally posted by greygirl1976

was your engine standard if it was u had a fault somewhere in the electrical system mate ive put an rb20t in a silvia and it went through the nsw rta emmision laws with a bov venting to atmo and passed with flying colours my car has been on the dyno with a bov venting to atmo it passes emmision laws  

Nothing wrong with my car electrics.

I'm not saying that a car fitted with an Atmo venting BOV won’t pass emissions testing, I’m saying that it causes off throttle richness however most turbo cars without tuning to suit fitted with an Atmo venting BOV won’t pass emission testing if tested properly.

Originally posted by greygirl1976

and gijor33 o2 sensors r in use all the time what do u think helps control a.f ratios

No only during cruise BTW it’s called closed loop. It’s used for fuel economy mainly and to help the cat converter to work hence emissions are corrected.

[GiJOr33]

i'm just telling you what i've learned too from reading the forum. I'm not saying i'm 100% right.

I thought air/fuel ratios are controlled by setting them up with ya laptop on the dyno. And that the O2 sensor is utilised in the warm up stage (as it's not a wideband O2 sensor) so that the ecu reads a hi/low signal (not sure which) so it can add more fuel while the car warms up. Once it's warm it switches back to what the ecu is programmed to do. That's why when you get an A/F Ratio guage from Autobahn they either read full red, or full green... never in between unless you have a wide band O2 sensor

I understand that the factory ECU is a learning computer, but it can only just things a certain amount, taking things like EGT sensor, TPS, and rev/speed history into account as it's designed specifically for that car with the idea that it will remain standard so the a/f ratios are programmed into the computer. I could be wrong, but if you've got a link i can read about your thoughts/experiences that would be sweet.

Cheers,

Andrew

[DAMQIK GTS-T]

Have a Look at the following links proves what I'm saying is pritty much spot on

http://www.scuderiaciriani.com/rx7/O2_sensor.html

http://www.jimwolftechnology.com/techadvice.html

http://www.autospeed.com.au/cms/article.ht...gestions&A=1513

http://www.teamfc3s.org/info/articles/fcd/diy_fcd.htm

some of these sites may not have info on the current topic but they should give a better understanding of certian efi functions

Enjoy

[greygirl1976]

sorry boys were all gettin confused here all my comments r on factory computer and factory sensors in not saying im right or worng and u guys r right or worng im only going off the cars ive done and tested and what ive been tought at work and tafe well were i used to work ill esrace there words from my memory gijor33 if u have picked all your info off this site its a good 1 coz u r 80% right .how about u damqik gts-t where did u pick up your knowlege you r pritty clued up uourself

[greygirl1976]

im actually on autospeed at the mow

[greygirl1976]

im on http//www.autospeed.com.au/a_0128/cms/article.html

[DAMQIK GTS-T]

2 years and a half years with RACQ Breakdown

3 years as and auto electrician

15 years self taught playing/modding with mine and others cars.

Currently a computer tech.

[GiJOr33]

fsck... i just wrote a big post and clicked the back button... so it's gone. Anyway, i reckon i'm right as that's what i've been told by plenty of people before

i had a stock skyline with exhaust/atmo venting bov and it blew black smoke on gear changes, and my current skyline has an aftermarket computer with a MAP sensor (so no more Air Flow Meter) and it no longer does it.

Andrew

[DAMQIK GTS-T]

GiJOr33 What ecu do you use?

I use a GTS link

[GiJOr33]

Originally posted by greygirl1976

im on http//www.autospeed.com.au/a_0128/cms/article.html

I can't get to that site... goes to the msn search thing.

I also logged into autospeed and tried typing in the url after and still no good...

[GiJOr33]

FCONV... needs a tune though

[greygirl1976]

yep i hate afm they sux i just need a aftermarkrt computer so i can do low 12s car shuts down{limp mode} at half track on 8-10psi

[greygirl1976]

justgo to www. autospeed.com.au click search and type engine management click all articles and then go

[lambo]

Can We Just place the BOV before the AFM so all these issue can be resolved?

[DAMQIK GTS-T]

No because then the ecu would read the same air twice making the engine even more richer.

[greygirl1976]

lambo we were tryin to help u we just got sidetracked

[GiJOr33]

yeah... the Air Flow Meter is before the turbo compresses the air, so you need to place the bov between the turbo and the throttle body. The cars that plumb the BOV back into the inlet does so AFTER the airflow meter, but before the turbo. So the air has already been measured by the AFM, and is just fed back inbefore the turbo to be recompressed. As it vents through the turbo it uncompresses. Some say that feeding the BOV back into the inlet just before the turbo helps to keep it spinning, this maybe so if the air is directed towards the turbo.

Although for most people the BOV is there cos they like the sound

[greygirl1976]

and screwed so loose it goes off at 1500rpm