Wideband AFR question

[v8s_are_slow]

Okay, I'm running around 14.7 at idle and around 11 at WOT. Question is, where should the afr's be inbetween? For example if I'm shifting into 3rd at around 40mph which is way out of the powerband but WOT. Should the afr's gradually come down or immediately come down? I wouldn't think they should immediately come down but just concerned about being too lean at part throttle or WOT at a low rpm and wanna be on the safe side here. I tried it the other day and saw 12.5 to 13 and decided to let off the gas cause it made me start thinking about the safety of it so figured I'd better ask. Thanks.

 

[iwannagofast89]

I'd try to stay around 13.5

 

[gixrman]

It really depends on your mods,IAT, TPS voltage and timing. 1g's have a more agressive timing curve. And I believe the factory ECU shoots for a 9:1 ratio under WOT. Are you knocking? 13:5 is way to lean under WOT. It really all depends on your setup.

 

[90gst_sean]

i think you'll be fine. some time there is lag between the engine and sensor.

what are you using to change your afr? link...

 

[turboglenn]

On a DSM motor, if you're running the stock compression ratio, you can get away with 13:1 at 6psi and under. I ran mine like that for years with no ill effects at part throttle acceleration. Then around 7PSI i start richening it up quick (gives an interesting look to the map) to about 11 - 11.5:1 when WOT or any boost over 7 psi. I think this is what you were asking, hopefully it is. What are you tuning with???

 

[v8s_are_slow]

I don't have any kinda datalogging right now so I dunno if I'm getting knock or not. It had a GM Translator for tuning when I got it. I figured it had to be pretty rich cause it'd kick and buck at the top of 3rd. Installed the wideband and pulled out some fuel and it runs much better now. But since I haven't been able to get any datalogging devices in it just yet, I'm trying to be as safe as I can with the tuning and wanted to at least make sure my afr's are close to where they should be and wasn't sure how long the numbers should take to drop down once the pedal went down. Thanks for the input.

 

[2gGSX]

I don't have any kinda datalogging right now so I dunno if I'm getting knock or not. It had a GM Translator for tuning when I got it. I figured it had to be pretty rich cause it'd kick and buck at the top of 3rd. Installed the wideband and pulled out some fuel and it runs much better now. But since I haven't been able to get any datalogging devices in it just yet, I'm trying to be as safe as I can with the tuning and wanted to at least make sure my afr's are close to where they should be and wasn't sure how long the numbers should take to drop down once the pedal went down. Thanks for the input.

Why risk it? Get/borrow a logger. You can get a Palm/cable for very cheap, and mmcd is free to download.

 

[v8s_are_slow]

Next mod I'm trying to get is Dsmlink and money is hard to come by so trying not to spend any money I don't have to on parts that'd be a waste down the road. Don't drive the car too much right now though until I have Link and it's not my only car so I'm safe there. My afr's when I went to the track last were at 10.9-11.0 at wot down the track where I ran a 7.7 in the 1/8th. Next time I go, I'm dumping in some 100-110 octane in to be a lil more on the safe side as well.

Reminds me of the guys back in the day before datalogging and all didn't exsist and just tuned off egt's, narrowband O2's, boost, and fuel pressure. Haha! Glad I can buy better items now.