AFR newbie question

[linuxrc]

I just got this car from a different owner who had an AFR wideband installed.

I think it looks great and all but I have no idea what the numbers mean.

Can anyone indicate what I am seeing there and really, what I should be seeing.

I'm running an SRT 8, with CAI, Cam, predator that's pretty much it.

When I start the car at idle it seems to be around 15.1 I haven't paid too much attention where it's at when I am driving but I am driving pretty conservatively right now and it hopes up and down to 14.8 to 15.7 sometimes?

Sorry if this has been beaten but I just need to get an idea what the heck is happening and what I should be looking out for in case of problems or something. Also is there anything I can do with this thing with a predator? Logging etc

[MadCharger]

In closed loop (partial throttle, idle, etc) the computer will be trying to maintain 14.7 (stoich) afr. It will always be richening and leaning to obtain 14.7, so you'll usually see it bouncing up and down from that number. When you go into open loop (wide open throttle), you should see it level out at about 12.5 or so, but it shouldn't be bouncing around. It will change, but gradually. 12.2-12.5 is where you want it to stay. It's a good thing to have since you have a cam upgrade, and that generally affects your afr fairly significantly.

[linuxrc]

hmm Ok i will pay some more attention to the numbers. I don't know if it goes down to 12.5 but I will check

[MadCharger]

hmm Ok i will pay some more attention to the numbers. I don't know if it goes down to 12.5 but I will check

Just make sure you still keep 1 eye on the road at WOT!

[linuxrc]

lol thanks for the advise

[higshemi-less]

Terry pull onto hwy8 in 4th(autostick) around 1500 rpm and hit for as long as you can. Your readings will be showing open loop. Let us know what you see.

[linuxrc]

Will do Fred

BTW Fred anyone in the club getting ready for dyno / tune days? I would like to get this car on a dyno and get a someone that knows what they are doing to give me a good tune.

[higshemi-less]

Can't help you out with a tune, but I'll be making some runs at Marken performance in a few weeks. 100 for 3 pulls.

[higshemi-less]

Find out who did the tune on your current setup. May not be needed.

[linuxrc]

Not sure who did the tune. But the name on the tune is Alex. I'm assuming from Franks Racing in Texas. But I'm not sure if he did the tune or not or if someone else did the tune.

The car right now idles at 15.0 to 15.2 - when I drive normal highway speeds it stays around that as well. If I hammer it, then I see the numbers go down a bit. I've seen it dip down to like 12 ish but I can't stay on it for too long I will be arrested.

I really want to get someone to take a look at some logs and create a proper tune for me. I just don't know if the car is running how it should be. I don't have a whole lot of reason to think it is not running right but sometimes i feel like the car is leaving something behind. Like maybe it's not quite what it should be in certain situations.

[higshemi-less]

I'm sure if it came from Franks tuner you'll be pretty safe. At WOT you want to aim for mid 12's in most cases. I wouldn't worry about dropping a few hundred on another tune Terry.

[CRS MSL]

Which wideband is it? If it's the zeitronix ZT-2 you can log right from the box with your laptop. You can then post the logs here and have smart fellers tell you where you're at.

[linuxrc]

I'll have to check.

I see a RJ-11 jack under my seat, I'm assuming it must lead to the AFR wideband. I'll have to look into it.

Yeah I'm not sure I'm real happy with the tune. Hard to say what it's doing. So I'm going to go to Marken tomorrow and do 3 pulls. I'll change the tune to 93 Perf CAI on one of the pulls to see if there's any difference.

Right now however I have 1/2 a tank of 91 octane with octane boost and the other half is 94 octane. blah.

[higshemi-less]

I think running the little boy cam with a canned tune is bad idea Terry. just my .02

[linuxrc]

hmm I c. I didn't think it would do anything bad but I don't know these things either. hehe.

Well I guess we'll see what it does on this tune. I'll try and log what I can and hopefully if I'm not happy with it, I'll get a tuner to look at it.

Maybe you should take it for a spin sometime Fred, see if it's running like it should. To me it doesn't seem to run right and I think it's the tune.