oxygen sensor questions

[supra shaun]

Originally Posted by supra shaun

so an o2 setup would be seprate and for monitoring purposes only

toyota o2 reference is only used by the ecu when up to temp and holding a consistant rpm, when the car is starting , cold , accelerating or deccelerating the o2 goes into an open loop and the ecu ignore's o2 reference.

[btwilson86]

Originally Posted by supra shaun

if im not mistaken the 87 7mgte doesnt use an o2 sensor

You are mistaken.

[cre]

Originally Posted by supra shaun

toyota o2 reference is only used by the ecu when up to temp and holding a consistant rpm, when the car is starting , cold , accelerating or deccelerating the o2 goes into an open loop and the ecu ignore's o2 reference.

Again no, that's not entirely accurate... and are you just posting as a means of thinking out loud? The ECU references the O2 sensor the majority of the time once warmed up, including when accelerating (at up to about 70% throttle). When decelerating (coasting down; off throttle and while the RPM are above the fuel cut level) the O2 sensor isn't referenced as the fuel supply is cut altogether. When decelerating below the fuel cut level or at light throttle the O2 sensor is referenced.... and so on and so on and so on... There are a LOT of conditions to this.

[supra shaun]

Originally Posted by cre

Again no, that's not entirely accurate... and are you just posting as a means of thinking out loud? The ECU references the O2 sensor the majority of the time once warmed up, including when accelerating (at up to about 70% throttle). When decelerating (coasting down; off throttle and while the RPM are above the fuel cut level) the O2 sensor isn't referenced as the fuel supply is cut altogether. When decelerating below the fuel cut level or at light throttle the O2 sensor is referenced.... and so on and so on and so on... There are a LOT of conditions to this.

well i disagree according to toyota thats not true heres a link on toyota input senor tech info http://www.autoshop101.com/forms/h24.pdf page 25 will explain how the o2 is used. my understanding is that the o2 is only used to keep egt's down while cruising and idleing, and in my opion a larger exhausts is a much better and more cost efficient way to control egt's


7mgte 475 to the rear wheels with no o2 at all unplugged and still running factory ecu and injectors and no e-manage either

[cre]

Originally Posted by supra shaun

well i disagree according to toyota thats not true heres a link on toyota input senor tech info http://www.autoshop101.com/forms/h24.pdf page 25 will explain how the o2 is used. my understanding is that the o2 is only used to keep egt's down while cruising and idleing, and in my opion a larger exhausts is a much better and more cost efficient way to control egt's

First off that article doesn't cover all the specifics for all the cars, just some of the major point... go figure, it's just a textbook. There's a group of engineers on SupraMania who've reverse engineered the complete TCCS... go talk to them about it, it's dizzying.

The O2 sensor isn't employed to reduce exhaust temps... it actually INCREASES them by leaning out the fuel mixture. Disconnect it and you'll be running in the 13's or richer and richer = cooler. EGR is employed to bring down cylinder temps.

Originally Posted by supra shaun

7mgte 475 to the rear wheels with no o2 at all unplugged and still running factory ecu and injectors and no e-manage either

Not buying it. You know jack shit about cars, probably haven't done any work on yours and have no idea what the people you paid to work on it did to it. The stock injectors can't supply enough fuel for the amount of air required for that kind of power, the ECU is programmed to cut fuel complete if a certain air flow is exceeded (keep reading I'm sure you'll get to this chapter soon enough and you can modify your story as needed then). Go back to whatever Mazda or Honda forum you usually troll on, your presence here is neither required nor desired.

God, all this jack assery has actually made me dizzy. Claims these cars don't even use an O2 sensor, then is suddenly an expert on how and when they do, what they're used for (which is also wrong) and he built a dragster out of his without making any mods?????

[supra shaun]

Originally Posted by cre

First off that article doesn't cover all the specifics for all the cars, just some of the major point... go figure, it's just a textbook. There's a group of engineers on SupraMania who've reverse engineered the complete TCCS... go talk to them about it, it's dizzying.

The O2 sensor isn't employed to reduce exhaust temps... it actually INCREASES them by leaning out the fuel mixture. Disconnect it and you'll be running in the 13's or richer and richer = cooler. EGR is employed to bring down cylinder temps.



Not buying it. You know jack shit about cars, probably haven't done any work on yours and have no idea what the people you paid to work on it did to it. The stock injectors can't supply enough fuel for the amount of air required for that kind of power, the ECU is programmed to cut fuel complete if a certain air flow is exceeded (keep reading I'm sure you'll get to this chapter soon enough and you can modify your story as needed then). Go back to whatever Mazda or Honda forum you usually troll on, your presence here is neither required nor desired.

God, all this jack assery has actually made me dizzy. Claims these cars don't even use an O2 sensor, then is suddenly an expert on how and when they do, what they're used for (which is also wrong) and he built a dragster out of his without making any mods?????

no reason too get mad but ill explain how to get 475 hp with stock ecu and injectors
first machine work, bored 50 over and it was also line bored because the thrush bearing spun chewed the block pretty good. then after market header and turbo with 46mm exteral waste gate, 3'' flow thru exhaust, greddy bolw off ,air flow meter housing from toyota ls 400 the 4.0 v8 (wich lets me hit about 22psi @7500rpm before fuel cut) and then a fuel pressure regtulater ajusted to about 62 psi when boosting 50 @ idle. and oh ya i also got the n/a intake cam with a aem adjustable cam gear bolted to the front of it. i almost forgot the rotating assembly was bought from rock performance with crome rings and i had it shot peened. beleive me im pushing 475hp buddy and ill put my money where my mouth is! you live florida? come visit my shop als affordable auto and trans lake park fl. licensed and insured look it up come see.

[cre]

You're so full of shit I can even taste it and I'm not pleased. So much wrong here it's beyond funny and stupid, it's insulting. The fact that you're trying to push it on other people is even worse. We HAD another member just like you... made our forum famous in a real crap way... I don't care for that sort of attention again... Goodbye.



I'll cut to the cliff notes and you can Google the rest when you reformulate your line of crap for whatever site you try it out on next (TIP try to avoid significantly old data as it may have been idle speculation which has been completely dispelled in recent years):

The 7M-GE intake cam has been dyno proven to be a significant BOTTLENECK past about 4KRPM... it just chokes the engine beyond that and the power curve falls flat... Go back to a GTE cam and you'll hit 500.

The Lexus AFM (just like the any other AFM) tells the ECU how much air is coming in whether you're pushing 12psi or 300psi and the ECU cuts fuel at the same volume of air either way. The Lexus AFM isn't good for anything beyond 350RWHP without modification and/or a fuel controller.

You work at a shop but for some reason think that not all cars sold in North America after 1980 have oxygen sensors??? And then that they're just they're for your own diagnostic purposes???

Oh, and you think the O2 sensor is for controlling engine temps???? Specifically keeping them down? RIIIIIIIIIGHT.