The new datalogit software has a nice map watch function which can plot your average value of the item being traced in a P vs N chart... The result is a Air Fuel value for each cell. The quenstion is what to shoot for..

I was thinking 14:1 on rows p02-p07 as they are light throttle (most of my driving), with just maybe 1 a/f higher at rpms above n09.

and then blend from p08 to p11 down to something like 12:1 for the rest of the map

 

Here are my min/max/avg/num values for my drive home from work Monday. The lower map was tuned by someone that set up MA emissions and the power cells where done by Dave at KDR. From the looks of things I will enrichen P16/N7 area next drive.

Minimum:

 

Max:

 

Try again...
Max:

 

Avg:

 

Sample counts per cell...
Num:

 

I say 14:1 for p02 tru p04, 13:1 for p05 thu p07, 12:1 for p08 thu p10, and 11.5:1 (or lower) for everything below.

I posted my chart from yesterday on another thread, but here it is again:

 

FD Racer, can you post your sample counts from this table? I assume this is from averages. Also, what hold off are your using and what wideband?
You must have driven a fair amount to get the table to fill that much.

 

grampa,
I'm using the DIY wideband.
My sample count for that run was 16138, I'll post the table too.
And yes it was from averages. I drove around for a while....according to the log it was 1509 seconds, or about 25 minutes You know that you can go back and review a recorded log on the map watcher in any hold off setting, right? The above was from zero hold off.

Here is the exact same run, also averages, but with 1000ms hold off:

 

Here are my sample counts on the map watcher:

 

I am using the DIY wideband as well. You have a good set of samples in your upper load cells, no tickets?
I have been doing mostly reviews of logs so far, did you know that you can paste several logs end to end in an editor and then review them all? It works for map watch but if you view the pasted logs in chart the timeline is a bit screwed up. I will probably write an emacs macro to do this for me along with correct the time stamps.
I have been using 0 hold off as well since from reviewing chart response times of the diy wb it seems plenty fast enough - unless I misunderstand the intent of hold off. Maybe once the manual is updated for the map watch feature it will be defined.
I do plan more logging sessions this weekend, I bought a power inverter last night so maybe I can get more time in before my weak laptop batteries bail.

 

Yeah I know a couple good streches of road, it's been fun Thanks for the tip on pasting the logs together, I just tried it on excel and it worked great!
It was recomended to use 1000ms hold off for widebands, which makes sence. The acurracy can only improve, however our cars move to quickly threw the map to get many samples at that rate. In 4th and 5th gear you can get some decent 1000ms samples, but the speed gets crazy quick
Funny, my laptop battery just took a dump two days ago, I got a new one ($200!! ) which is soooo much better.

 

fdracer...those maps are looking good..great actually.

I added even more fuel to the lean areas in my maps after our map watch runs and the car is feeling a LOT better...cant wait to do another wideband run and see where things stand.

great thread guys.

j

 

I love the Map Watch setting, I know people are skiddish about posting maps because they are so particular... .1 in a PIM could pop somones motor... this gives people the ability to share tuning info which for a few hundred bucks anyone can put to good use..

Thanks for the great response.

One thing I noticed... there is a .2v difference between the ground wire to my O2 sensor, and the frame... this caused me to have to rework my polynomail to compensate... anyone else seen this...

 

Question ... why do you want you AFR really high at the low rpms and low and the high rpms? Shouldn't it be the other way around?

At the low rpms have a lower AFR ratio so that you don't burn up a lot of gas, and at the high rpms have a higher AFR to keep from detonation?

 

Air-Fuel Ratio is frequently used in the analysis of the combustion process. It is usually expressed on a mass basis, i.e.

AF=(mass of Air)/(mass of Fuel)

LEAN (A/F > stoichiometric)
RICH (A/F < stoichiometric)

For pump gasoline I think 14.7:1 is stoichiometric.

If the A/F ratio is LEAN, then excess O2 will be present in the exhaust.

If the A/F ratio is RICH, then excess fuel will be present in the exhaust.



Read and study this

 

I know all that badog ...

I'm asking why are their AFR rich in the low rpm's and lean at the high rpms??

 

What makes you think someone wants that?

 

xph,
Please share with us your findings. How/where did you measure the voltage difference? What did you adjust your Polynomials to? I'm taking the raw output logging and converting it over on excel using:

y=1.6344x^2-2.1693x+9.9414

Do you know of any pros/cons of converting it like this?

Thanks

-Ray

 

Scroll up and read ...

 

I dont see it.
I dont think anyone *Wants* to be richer up top than down low. Thats why we are tuning to get it nice and balanced.

Do you have any charts from your logs to share?

 

Not be an **** here, but you're confused. Reread your statement above.

I don't think anyone wants their AFR leaner than 14.7 at high RPMS.

Personally, I don't really care about low RPMS with no load. I care about high RPMS with high load being tuned on the rich side of 14.7 (to be safe.)

If you read that link I referenced, it talks about what LEAN LIMITS and the role ignition plays.

 

Are you Kevin in the datalogit and OZ-DIY yahoo groups? If not, check out those groups.

TK

 

FDRacer,

Could you post your KNOCK values for that run as well? I'm really curious how I compare with similar readings.

David

 

Sure...here are the MAX knock numbers. I'm not sure what up with the ones at idle....obviously an error.