I need help getting the most out of my car

[dvx]

My car is a 99 Z28, with t-tops & all options. It has the original bottom end with 45k miles on it. I have installed dart 225 heads, comp 228/232 111 +1 cam, 1 3/4" long tubes + off road Y, LS6 intake, svo 30# injectors, underdrive pulley, TCI 3500 SSF converter, and 3.42 gears in the factory rear. I also lowered it with eibach springs, revalved blisteins, bmr lca's/brackets & panhard rod. It has 17" wheels with 315 ET streets on the rear. It also has slp subframes, for even more added weight. I am running OLSD.

I did the motor mods a few years ago and have done my own tuning. This car is just a hobby and I haven't had much time to really try to get it dialed in for WOT. I don't currently have access to a dyno but I have been to the track with it a few times. It runs strong, but the best I have been able to get at the 1/4 is:

60' - 1.794
1/8 - 7.700 @ 91.01
1/4 - 12.027 @ 112.08

I feel my car should run at least .3 quicker in the 1/4 mile. Am I being realistic or am I expecting too much out of it? I think I just don't know where to go from here with the tune to get the most out of it.

I have attached the tune and log file for the above run. I have tried running it leaner, which results in loss of mph, a slightly slower ET, and it picks up more KR. It always picks up some KR at launch.

Any advice would be greatly appreciated.

[joecar]

Hi dvx,

First fix this:

Out of Range calibration summary: 12:47:18 pm, Sunday Oct 24, 2010

EFILive Custom Calibrations
{A0001} Forced Octane Scaler Percentage, was out of range when loaded.
{A0002} Octane Scaler Limiter, was out of range when loaded.

Also fix A0012, A0013... see the blue dog ears in those cells (means out-of-range).


Set those cells to 99,99,511, 511, save file, exit... then open file, set them to 100, 100, 512, 512, save file.

[dvx]

Thanks for taking a look joecar. I was confused by those errors since they weren't actually set out of range. But I figured it wouldn't really matter since I had A0000 set to disabled. Do you think this was causing any issues? I have never been able to get rid of 100% of the KR, no matter how much timing I pull or how much fuel I add.

[joecar]

IFR looks good/right... what is your measured rail pressure...?

VE table doesn't look quite right... altho I see your WOT BEN is within ±3%. You're not boosted, right...?

In the VE table, flatten out the single spikes, and bring the holes up a little... you might want to do another AutoVE pass (should be fairly easy).

If you're not boosted, I see your WOT AFR is rich at 12.0, you could probably make a little more power by commanding 12.6 (and checking that your wideband reads the same); when you do this timing may now be a little too high, if it starts knocking take 2° off where it knocks.

Your injectors are almost running out of flowrate, but changing the AFR from 12.0 to 12.6 might fix that.

Do you have FlashScan V1 or V2...?

For SD, log DYNCYLAIR or DYNCYLAIR_DMA instead of CYLAIR. Also log DYNAIR for calculated airflow.

Also, you can increase the trans shift pressures, and reduce shift times to 0.2s.

[joecar]

Thanks for taking a look joecar. I was confused by those errors since they weren't actually set out of range. But I figured it wouldn't really matter since I had A0000 set to disabled. Do you think this was causing any issues? I have never been able to get rid of 100% of the KR, no matter how much timing I pull or how much fuel I add.

When cells are out-of-range, the tunetool displays the closest in-range value.

I don't think those were causing any problems, but the PCM has to do special handling when reading those cells.

[joecar]

That small KR is ok, it's on initial load increase.

The important thing is to avoid knock at WOT high-load.

[dvx]

joecar - I really appreciate you taking the time to look at this and your feedback is greatly appreciated.

My car is not boosted, it's n/a. I have not measured the fuel pressure at the rail. It doesn't appear to be running out of fuel, but it would be a good idea to check it. I will have to pick up a gage.

I will work on the VE table a little more. I have spent most of my time on driveability tuning and very little on WOT. I have a question though. For PE mode, when I compare the WB AFR reading to commanded, 1st gear shows a little lean. 2nd gear is pretty close to where it should be. 3rd gear shows a little rich. Is this normal? Is there anything I can do to get fueling correct for all 3 gears?

I will play with commanded PE mode a little more. I have had it all over the place though, from 11.75 - 13.00. I had the lowest ET at 12.00. I have no way to verify that my wideband is accurate, so I'm going on the assumption that it is.

How much timing should I be able to run at WOT? And do you think it would be a good or bad idea to tweak the knock sensor tables? I have left them alone for obvious reasons but I am wondering if the boost in compression and cam could possibly lead to false readings in PE mode.

I have Flashscan V2. Up until last week it hadn't been connected to the car for over a year.... life got in the way of the car (I got married... bad mistake... long story). I have updated everything to the latest software/bootblock/firmware.

[dvx]

The big spike in my VE table is from where I copied/paste & multiply from my log file. It is definitely out of wack! I guess this is from where it dips to lean and then rich before smoothing out when I drop the hammer on it. Trying to adjust the VE table to compensate there probably only makes things worse at launch, and results in a longer delay in getting AFR where it should be.

[joecar]

Each gear loads the engine a different amount, so airmass will be different, so it will run differently (AFR)... I'm not 100% sure, but this may be an indication that the airmass source (VE and/or MAF tables) may need a little more work... VE table in this case (since you're OLSD).

Timing is hard... keep stock timing until you can get some dyno time.

Valvetrain noise can be picked up by knock sensors, usually this will be at consistently specific rpm's.

If you have FlashScan V2 then you should be using the serial comms interface, your wideband supports it...
see here (follow LINK's in post #1): showthread.php?14650-Setting-up-my-LC1-using-a-TAQ-Cable

Ok, good you have latest sw/bb/fw.

Sorry to hear that life got in way of car... a guy's car is what keeps a him sane thru life.

[joecar]

The big spike in my VE table is from where I copied/paste & multiply from my log file. It is definitely out of wack! I guess this is from where it dips to lean and then rich before smoothing out when I drop the hammer on it. Trying to adjust the VE table to compensate there probably only makes things worse at launch, and results in a longer delay in getting AFR where it should be.

With a cam change, fueling dynamics (how fuel wets port wall and evaporates from it) changes... there are fueling dynamics tables to play with... also since cam changes IVO event, there is an injector timing table that can be played with... those "squiggles" are related to fueling dynamics and injector timing.