I don't know much about afr's. I do know my car has a AEM gauge and it dances all over. On start up its in the 12-13ish numbers, once it warms up its 14.7ish to 16.2. I know the car wasn't tuned after the previous owner cammed it, which is on my list. Car smells extremely rich. Just trying to get an idea. Thanks

 

Is the AEM "gauge" hooked up to the stock sensor?

If so it is totally pointless.

This is the scenario I expect from the previous owner having done a cam with no tune.

If a standalone wideband then AFR at different conditions can be discussed.

The stock sensors ONLY read 14.7:1 and the computer varies cruise AFR to above and below that so it can "see" that the sensors are functioning and responding. So it is completely normal and even desirable to see it dancing around.

At WOT the AFR needs to be high 12s or maybe very low 13s BUT the stock sensor is not accurate there even if the "gauge" is giving you a reading.

 

No, it has the supporting wideband sensor. The car was built properly, however he lost intrest after he cammed it. So no tune the numbers do fluctuate lower at wot. I know its a vuage question, just looking for some ball park numbers in comparision to what I'm seeing.

 

Then like I said around cruise it should float back and forth across 14.7, at WOT it should be say 12.5-13.2

I am not familiar with the AEM setup, does the wideband require recalibration periodically?

 

AEM is not supposed to need a calibration. I think it does something like a recal when its turned on.

I have the same WBO2 and at cold start up I see around 14.5 or so open loop. Once it goes closed loop, it bounces between 14.5 and 15.5 like it should trying to maintain 14.7 stoic. At WOT, mine locks in at about 12.8 or so.

Its a decent WBO2 from what I have gathered an the easiest to install.

 

Thanks, like I said just a curious question. Never hurts to know a little more.

 

I have the AEM wideband and mine does the same thing. I asked on here awhile ago and people said it was normal. but im still adamant that my tune isnt 100%. it will see 14 down to 17 at idle or cruise

 

This sounds about like mine, although 16.2 is about as high as it goes.

 

I have the AEM UEGO on my LS car. It's a very accurate simple and reliable wideband.

Mine would go as lean as 16.2 on cruising and idle, and had a bad lean spot right around 3K.

I had to spend some time tuning the VE tables til I got them near perfect, but now it is VERY close to 14.7 all through the RPM range and WOT is dialed in where I want it as well.

No one takes the time to dial in the VE tables and that is the heart and soul of the tune. On yours even more so because it doesn't rely on the MAF to correct them. I would spend some more time on the tune.

 

I have the UEGO as well, I need to get a good tune I suppose...he told me when I bought it what the situation was as far as whats been done and what was needed. It runs like a raped ape as is, I would imagine it will be a whole new beast tuned. At any rate thanks for all the input.

 

There may not be a lot of topend performance gain, but a tune should start from the bottom up, not the top down like most do.

Tuning everything starting from idle all the way through the RPM range makes the car so much more responsive and fun to drive. Plus better mileage and more efficient.

 

Well said. thats something that i know i need. i was going to get a tune but for some reason the tuner couldnt get the software to read my computer.... fml

OP, just get a good tune on the car

 

Yup Yup Yup.

 

Mine runs about the same and i know my tune isn't 100%, I was reading somewhere that if it is not wired with its own power and ground that it could give false readings.

 

sounds like a good candidate for a 24X conversion itll make your tuning easier and cheaper, and your car more reliable

 

Unfortunately the 24x can cost a very pretty penny.

 

I have a LM2 running on my 396, the tune is by Ed. I will read around 12.8 when I'm on it, around 14.3-5 at part throttle and 17-18 at no load.

 

My AFR on my 455whp pull was 12.7:1. That ballpark seems to be the norm.

 

12.7 is a tad lean for our motors most people will tune at 11.8 rich is safe lean is mean. 12.5 is the money its where the most power is made however it tends to get a little hot around there. then again most every tuner tunes rich because you will never make any money tuning if your blowing motors up.

 

Every engine is different. FYI, STOCK LT1 programming targets 11.7:1 at WOT. There is nothing wrong with 12.7:1; that's where my car made the most power.