Gz21 Posted June 8, 2004 Report Share Posted June 8, 2004 I have a question on air/fuel ratio's. I have been tunnig my car during the last week and it is actually going good, much better then i thought. I am using the hawk on my car. But I dont think that matters much for my question. There is a scale/guage on the hawk tuning screen that shows the air/fuel ratio and I have an autometer air/fuel ratio gauge. The voltage from the oxygen sensor is displayed under it the one on the hawk. Based my air fuel ratio gauge and the hawk my car is high in the stoich region while steady cruising and sligtly rich while under boost. I want to know...If the car is showing full rich on here...what kind of air fuel ratio does that correspond to? And what kind of voltage is a good stoich mixture for cruising? I am sure somebody has to know this. Thanks, Craig Link to comment Share on other sites More sharing options...
88TSI_Rob Posted June 8, 2004 Report Share Posted June 8, 2004 Are you using a standard O2 sensor or a wideband? I wouldn't try to tune your car using a standard O2 sensor. They are only accurate in the stoich range. Full rich could mean anything between 13.5:1 to 10:1 or worse. If your just looking for a stoich mixture at cruise I believe you'd want 0.5V from a standard O2 sensor. Link to comment Share on other sites More sharing options...
shift1313 Posted June 8, 2004 Report Share Posted June 8, 2004 it depends on what the hawk is asking for. is it asking for air/fuel ratio, ve , or actually asking for a voltage input from the o2 to make corrections? idle usually around .45v - .5v as rob said.. full rich under accel goes up in the .9s somewhere but you shouldnt have to input that anywhere( i think). i think 12.7 is about where you want to be, but you should wait for more responses from people with the hawk. Link to comment Share on other sites More sharing options...
89tsi20g Posted June 9, 2004 Report Share Posted June 9, 2004 i would shoot for 11.5-11.8 if more than on 5psi of boost on wideband, Rob NJ. Link to comment Share on other sites More sharing options...
Gz21 Posted June 9, 2004 Author Report Share Posted June 9, 2004 Thanks guys. This is atleast a start to what I am looking for. That and I just got off the phone with Steve at EFI Hardware and i got alot of good help. Basically the Hawk is looking for a voltage from the oxygen sensor. And .5V is stoich at 14.7:1. I am using a standard narrow band oxygen sensor. I did not know they are not accurate for tuning other then at steady cruise. So where can I get a wideband oxygen sensor? Right now at steady cruising mine varies from .5 up to about .8 I am trying to bring this down closer to .5 Link to comment Share on other sites More sharing options...
WTFISIT Posted June 9, 2004 Report Share Posted June 9, 2004 Don't trust your narrow band O2. Â If you are really trying to make power, you will blow your engine up. Â Search these boards for wideband. Â There have been several threads recently. Â I think you can get a decent unit these days for less than $400. Â Narrowband = evil if you actually listen to it. BTW, stoich is not what you want if you are looking for power. Like other have said, you need to be aroun 12.5 or below while under boost. Anything else will bring you trouble and less power. Link to comment Share on other sites More sharing options...
shift1313 Posted June 9, 2004 Report Share Posted June 9, 2004 join the yahoo megasquirt site. they have a diy wb emmulator then you can find a wb unit for around 100 bucks or so. Cheapest way that ive found so far. Link to comment Share on other sites More sharing options...
88TSI_Rob Posted June 10, 2004 Report Share Posted June 10, 2004 The DIY wideband controller is a great option. Although if you want a commercial product I made a listing of the more common ones recently. http://www.starquestclub.com/index.pl?boar...;num=1081628412 Link to comment Share on other sites More sharing options...
Gz21 Posted June 11, 2004 Author Report Share Posted June 11, 2004 For you guys that have a wideband sensor mounted, did you mount it in the stock location? I only ask because I was reading on PLXDevices website and they state that they should be mounted a min of 24" from the block or turbo are if exposed to exhaust gases over 850C the sensor will fail. Now I am not sure what the temp of the exhaust is right after the turbo but I just want to make sure. Link to comment Share on other sites More sharing options...
Joel Posted June 11, 2004 Report Share Posted June 11, 2004 You have to mount it as they say. Mine mounted at 16" back from the turbo outlet is still a little to close. Some days after I shutdown heatsoak disables the sensor at startup if the car sits for less then 10 minutes. Narrowband o2s are useless for tuning. Wideband should be used only. Joel Link to comment Share on other sites More sharing options...
Shelby Posted June 12, 2004 Report Share Posted June 12, 2004 ok quesion can the hawk use a wide band 02 , or is all we can do is use it as a monitoring tool and tuneing tool ?? and just how much correction can the hawk do with the 02 reading it recives,, and is it utilize'd at all during wot under boost Link to comment Share on other sites More sharing options...
WTFISIT Posted June 12, 2004 Report Share Posted June 12, 2004 Many of the wide bands these days have a simulated "old school" O2 sensor output that you can tie to your computer. The lambdaboy, which I have, jus has an output that goes high/low either side of stoich, so I suppose if the ECU is really expecting to see a varying voltage it could be a problem. I haven't used the simulated output though, so I don't really know if it's an issue. Link to comment Share on other sites More sharing options...
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