Low timing in PE Mode

[LSChris]

I've gotten the driveability aspect of my Regal pretty close and I'm slowly working my way into tuning for power. I am tuning via the narrowband. I scaled the entire upper portion of the MAF up because the car was dangerously lean (770 O2s) in the upper RPM range.

I figured it was safer to start tuning some heavy throttle apps then jumping right into a WOT second gear pull.

There's one point in this scan where I get about 5 psi, but it is only commanding 9.5 degrees of timing while the corresponding cells in the table show 13-15 degrees of timing. (Starting around frame 4000)

It is not hitting any cells in the IAT or ECT spark modifier tables.

Car is a 99 Regal LS, top swap

Is there a table im missing or something? Can somebody clue me in? Is this some kind of torque management?

[Perforator]

Not sure about your timing problem but I bet if you throw a wideband on there you are running really rich. You have higher maf numbers than I do and I'm running a 85mm maf scaled down 5% at 11.3:1 verified via a wideband.

[LSChris]

I don't have access to a WB. I went out tonight and did some WOT runs. 8 degrees timing, O2s low 900s. High octane table still 15 degrees.

[bilemke]

Two questions..

1. Is that a L36 OS/cal? It doesnt look like a L67 OS I have seen before.

2. When the advance starts looking weird in your scan, have you taken a look at the timing advance for the Low Octane Spark?

[LSChris]

It was a stock cal I downloaded from the repository said to be for a 99 GS.

It does indeed match up with the low octane table. For some reason I had it in my head that it didn't match up with that table previously. What would cause it to switch to the low octane table just in high airflow/load areas if there is no knock? Should I try a different cal?

[bilemke]

I imagine only knock should make it switch to the other table. I have not seen a reason for it to do so otherwise.

Do you have the stock cal that came from the car (vs the one you downloaded from the website)?

Also, have you modified any of the knock retard/attack/etc settings (I dont have the stock version of the file you are using now to compare it against stock)?

[LSChris]

The car is an LS so it came from the factory unboosted (I do have the file for it though). I don't have a "stock" version of the file I'm using either because it was posted modified for a lightly modded car. (3.5 pulley, t-stat, remove torque management) The other file in the repository for a 99 GS didn't seem to jive well with my car. I tried it today and it was very reluctant to lock the converter and was jumping the gun unlocking it.

At first I had left all the knock settings alone. I compared them to other stock GS bins and they all matched. I made some tweaks to them, but the problem was evident beforehand as well.

[robfromlouisville]

i have a top swap 99 gp and tune from zzp, this is for the m90 top swap kit ,but i have 36lb injectors ,, hope this helps you out some!!

[LSChris]

Thanks Ill give that a look. What MAF are you using?

[robfromlouisville]

i have ported gtp tb stock gtp maf ...i just done a 2%scal up when i added my airwiz cai i still run a little rich but i like it like that!! but over the winter iam going to LS1 maf and 42 injectors ..

[LSChris]

Larger throttle blade and MAF hump removed?

I have a 99+ TB, stock bore size but it has the MAF hump removed.

[footman]

So what happens if your narrow band shows 940s and the wide band is showing 12 to 13??

[danthurs]

One of them is not right. Is it the wide band? or the narrow band? Look at your LTFT as well, + is lean, - is rich. WB need to be calibrated a lot. Perhaps 2 to 4 times a year. Look at your manual. My LC-1 I need to remove the O2 probe and turn it on, let it get hot, then push a calibrate button for 3 seconds.