01 cobra A/F ratio

[Michaelslilgray]

Sorry if this has been covered... but every time i use search i get a server error...

Ive got an 01 and just put a wideband on it... my A/f is all over the place and from a 2v standpoint pig rich. Is it that big of a difference in 2v and 4v? In my 2v my A/f was steady at 14.6 and was told thats where it needed to be... this car is running damn near 12.2 what i was told was forced induction territory back in the day... what the hell is my car suppose to run?

 

[ninty9cobra]

i believe f/i cars air fuel are around 11.5-11.8 and n/a cars air fuel somewhere in the 12ish but i maybe wrong

 

[Michaelslilgray]

11's would be bloody rich... like dripping out the tailpipe rich lol So god i hope not

 

[slonech]

12.2 at idle or in the throttle? idle should be 14.6

 

[Michaelslilgray]

idle is around 14.6-15.0 full wot is between 11.9 and 13.1

 

[01yellercobra]

Is the car tuned? Part throttle sounds ok. But WOT needs some work. When I was N/A I kept it around 12.5. With the blower I'm at 11.5.

 

[slonech]

yeah seems like you need a little more work on your Maf transfer table if its that much of a variation... looks like your sig shows a SCT can tune so probably benefit from a datalog and have that tune tweaked if nothing else.

 

[Michaelslilgray]

Can I not get it closer (no way perfect I understand) with the wideband? Everyone always says that its not possible but whats the difference between my wideband and a sniffer on a dyno... hell theres is closer to the end of the trail anyways lol

 

[Michaelslilgray]

So is my targeted area im looking for 12.5-12.8? (like i was saying) in my GT 14.6 wot was where my tuner had me put it on a dyno tune (using a diablo mind you) so I figured it would be closer to that... whats so different in these 4v that the a/f is so low in comparison?

 

[01yellercobra]

Can I not get it closer (no way perfect I understand) with the wideband? Everyone always says that its not possible but whats the difference between my wideband and a sniffer on a dyno... hell theres is closer to the end of the trail anyways lol

The reading at the tailpipe is the least accurate. You want to take the reading as close to the engine as possible. That's why wideband sensors are installed so close to the engine.

So is my targeted area im looking for 12.5-12.8? (like i was saying) in my GT 14.6 wot was where my tuner had me put it on a dyno tune (using a diablo mind you) so I figured it would be closer to that... whats so different in these 4v that the a/f is so low in comparison?

If your tuner told you a good A/F at WOT is 14.6 you need to find a new tuner. That's way too lean. IMO opinion 12.5 is a good N/A A/F. Some guys prefer 13.0. But then I've always tuned on the conservative side.

The difference is you're running a canned tune (which I didn't see because I'm on tapatalk). Most canned tunes are set up very safe because they're a one size fits most. To get the most out of your combo you need a custom tune.

 

[TBCobra]

Sorry to hijack but what is a good wot a/f for a nitrous car?

 

[Michaelslilgray]

Not hijacking at all... we need a one stop place for this to be answered...

 

[01yellercobra]

Sorry to hijack but what is a good wot a/f for a nitrous car?

Have you asked in the blower bistro?

 

[CJK440]

The reading at the tailpipe is the least accurate. You want to take the reading as close to the engine as possible. That's why wideband sensors are installed so close to the engine.

Actually a heated wideband can be located anywhere in the system and will read just as accurate assuming no leaks in the system. The reason o2 sensors were placed close to the motor is so they will heat up. The new sensors are heated and don't care. The tailpipe should be good to assuming it is sampled correctly.

 

[01yellercobra]

Last time I was on the dyno I had the sniffer in the tailpipe and my wide band by the header collector. I saw a bit of a difference. Like .2 or .3. I didn't have cats at the time. Personally I prefer it by the collector.

Oh, and I did run the wideband behind my new cats for a bit before having a bung installed. It showed about 1 point leaner then it actually was like that.

 

[Michaelslilgray]

Ive currently got mine in the post cat bungs so possibly lean out my mixture a little more than that lol

 

[01yellercobra]

Ive currently got mine in the post cat bungs so possibly lean out my mixture a little more than that lol

If you're showing 11.9 after the cats it's way too rich. Do you have the options in yiur tuner to adjust the fuel?

 

[Michaelslilgray]

I dont have cats... just using the post cat bung lol

 

[TBCobra]

Have you asked in the blower bistro?

If I go ask over there are you going to answer over there? lol

 

[01yellercobra]

If I go ask over there are you going to answer over there? lol

Sorry, didn't mean to sound like a dick. I just suggested it because nitrous guys hang out in there too. If I knew the answer I'd give it to you. I've heard that a nitrous car will show an N/A A/F ratio. Like 12.5-13.0. But I've never run nitrous so I don't know for sure.