Okay, my table looks REALLY weird. Check out these numbers. Do they seem weird to anyone else? If you need more info like the temp table, let me know...

400 - 4.7
800 - 4.7
1200 - -0.8
1600 - 1.2
2000 - 1.2
2400 - 3.9
2800 - 3.9
3200 - 3.9
3600 - 3.9
4000 - 3.9
4400 - -0.8
4800 - -1.6
5200 - -3.5
5600 - -7.4
6000 - -7.4
6400 - -7.4
6800 - -7.4

There's just not a very good "flow" to it. Why the big drop just above idle?

That one just seems odd to me.

 

If your temp table is stock, this is the A/F you are commanding with the coolant temp anywhere between 176* and 220*. I wouldn't worry about what is in the table off idle. How often are you in PE mode off idle?

RPM -Commanded A/F
0400 -12.21945137
0800 -12.21945137
1200 -12.80487805
1600 -12.58561644
2000 -12.58561644
2400 -12.30125523
2800 -12.30125523
3200 -12.30125523
3600 -12.30125523
4000 -12.30125523
4400 -12.80487805
4800 -12.89473684
5200 -13.1132917
5600 -13.58595194
6000 -13.58595194
6400 -13.58595194
6800 -13.58595194

 

Yep that's what a stock table looks like. Nothin strange there.

 

Those numbers you calculated are not correct. I'll post the correct values in a minute. The stock PE vs Temp is 16 at normal operating temp, and the numbers he posted are mostly negative in the higher RPM's of PE versus RPM.

Dan

 

400 4.7 11.6571
800 4.7 11.6571
1200 -0.8 12.4656
1600 1.2 12.1716
2000 1.2 12.1716
2400 3.9 11.7747
2800 3.9 11.7747
3200 3.9 11.7747
3600 3.9 11.7747
4000 3.9 11.7747
4400 -0.8 12.4656
4800 -1.6 12.5832
5200 -3.5 12.8625
5600 -7.4 13.4358
6000 -7.4 13.4358
6400 -7.4 13.4358
6800 -7.4 13.4358

Here are the correct values. Assuming that the PE versus Temp value is 16.
A/F = 14.7*(1-(PE versus RPM+PE versus Temp)/100)

To answer the original question, yes the numbers do look a little off, but if they work for your setup, then it should be fine. What mods do you have?

Dan

 

I was reading and reading and looking and looking at threads last night.

I read about this table and what it did. But I must have confused it with another table. I wasn't thinking about this being a WOT / PE table...

...But while we're on the subject...

Would you guys agree that there should be some sort of "flow" to the numbers vs. bouncing all around then staying the same?

What is the "best" AFR to run at during WOT?


Give me one sec and I'll post my mod list.

 

Above & Beyond Stock:

3-Angle Valve Job
1.52 Roller Tip Rockers
1 3/4" Primary LT Headers
3" True Duals w/ 40 Series Flows
3" High Flow Cats
!TB Bypass
!EGR
!AIR
Aeromotive AFPR
Walbro 255 lph Fuel Pump
CAI w/ Trick-Flow Elbow and K&N Filter
CC305
355 CI Rebuild
12.0:1 CR

Yeah, I think that's the jist of my "mods" that would affect my motor...

 

My whole reasoning behind asking the original question is that I'm having some "stalling" issues here and there. Then sometimes it just "bogs" when I give it gas. As if it isn't getting gas. So I'm just searching and searching through the tune to see if anything stands out. This table just seemed odd to me...

 

Heads are unported, just have the valve job?

I shoot for 12.8-13.0 for WOT a/f

Unless you have the stock cam, it is very difficult to use the calculation I posted above to figure out the real a/f at WOT. For my bolt-on car, it is accurate within 0.2 a/f, but I calibrated my MAF which is important.

This is where a wideband O2, or measuring the a/f on the dyno really helps.

You can also get a rough idea of where you are from looking at the mV of the stock O2 sensors at WOT. 0.8 mV = roughly 13.8 a/f, 0.9mV = roughly 12.7 a/f, so I target close to 0.9mv, but the stock O2's are not accurate at those mV readings so it is just a swag. Mine track very close to 0.89-0.91 mV at WOT, but I don't have any exhaust leaks, or intake leaks...

Are you able to get a datalog using something like Datamaster? (1st 20 datalogs are free)

Can you describe the bogging in more detail? It's hard to know what might really be going on without looking at the actual tune and a datalog to go with it.

Dan

 

Hmmm. I havent messed with this table yet. When i was tuning my car and getting my a/f where it needed to be i was using my MAF tables to get it into the 13-13.5 range.

 

Yes I know the formulas. I use I use 14.7/(1+Coolant Temp Value/100+RPM Value/100) which some consider to be more accurate. I also use 15.6 which is the actual value in the Temp Table.

 

This is a stock table for a 95 Z28. Yours has definitely been changed if those are the numbers in your table. it looks like someone really leaned it out. Maybe that's why it stumbles

4.7
4.7
-0.8
-0.8
0.8
0.8
3.1
0.0
1.6
0.8
2.3
8.6
9.8
6.6
2.7
2.7
2.7

 

12.8-13.0 is better.

What you did is one way to do it, but prone to error at partial throttle in the RPM's that you calibrated the MAF for at WOT.

You want to calibrate your MAF using the partial thottle long term BLM's. That will tell you how far off your MAF is reading from optimal (blm=128). Once you get your MAF so that your long term BLM's are close to 128 at all rpm's, then your MAF is calibrated, or at least set up to read correctly to give you the BLM's you want.

Then you use the PE vs Temp and PE vs RPM tables to set your a/f at WOT. That way, the car runs at 14.7 a/f at partial throttle as desired and 12.8 a/f at WOT. You can work only with the PE vs RPM if you want. You can see why from the calculation I posted above.

Dan

 

What do your maf tables look like?, if your tables in your maf tables arent right it could cause the same thing.

 

Great information. Thanks