Lean on launch
Don't believe your wide and on launch. They are never right. They don't responds as quickly as needed at that point. Only way to tune fueling at launch is by your 60' times, providing your car dead hooks. It is an automatic?
Some wide bands are slower than others. Innovates are the slowest I have seen, but none are correct at launch.
Some wide bands are slower than others. Innovates are the slowest I have seen, but none are correct at launch.
You could look at the filtering / averaging settings
in the wideband, any use of that will slow the output
response. But it is a slow instrument regardless.
Then, too, so is the MAF. That's why when you mash
it, the MAF is ignored for a while and you run off the
speed density part of the tune.
Which has its own filtering applies as you traverse
the MAP*RPM "surface", and people get some degree
of throttle response improvement from messing with
that, I gather. Though what the downside of going
too far might be, I do not know.
in the wideband, any use of that will slow the output
response. But it is a slow instrument regardless.
Then, too, so is the MAF. That's why when you mash
it, the MAF is ignored for a while and you run off the
speed density part of the tune.
Which has its own filtering applies as you traverse
the MAP*RPM "surface", and people get some degree
of throttle response improvement from messing with
that, I gather. Though what the downside of going
too far might be, I do not know.
Thread Starter
Staging Lane
Joined: Mar 2009
Posts: 60
Likes: 0
From: Devils Lake, ND
Again, appreciate the responses. The reason for my concern about the lean on launch is in fact directly related to my 60ft times at the track. They are all over. They can vary by as much as a 10th on the same day. Logs say I have no spin. I have also experienced bad heat soak which I have to get figured out(144 degrees on some warm days). Its pulling timing which seems to make the car run lean also. In addition it appears my converter is tight. Need to have it recalibrated up to 3600 stall. I can deal with the mechanical issues. I really want the tune on so i can move on to having fun with the car.
Thread Starter
Staging Lane
Joined: Mar 2009
Posts: 60
Likes: 0
From: Devils Lake, ND
The car is an automatic car. Built 4l60e. The wideband is a NGK AFX. So with all the monitoring and logging equipment I have are you saying that I really can't believe any of it at least for the first 4 seconds of a pass. Very disappointing.
When I tune an A4 car with a high stall convertor, I lock the trans in 2nd gear (3rd gear if the tires spin) and while driving at 1000 RPM, lock the torque convertor and then go WOT.
Your IFR table is still 4.5% too low, thus your Maf table is a lot lower than stock. Are you sure your wideband is accurate?
Russ Kemp
Your IFR table is still 4.5% too low, thus your Maf table is a lot lower than stock. Are you sure your wideband is accurate?
Russ Kemp
Your narrow band O2s all through 1st gear indicate it is not a WB O2 sensor delay. It does go lean/rich/lean/rich. Then in 2nd gear it stays rich. You need to find a way to monitor your fuel pressure. I've seen a lot of transplants where with a low level of fuel in the tank the pump pickup won't pick up fuel on hard acceleration. I think you are losing FP on launch.
Thread Starter
Staging Lane
Joined: Mar 2009
Posts: 60
Likes: 0
From: Devils Lake, ND
Thanks RussK. I know how to lock the trans in 2nd gear using the VCM controls. I'm not sure how to lock the torque converter. Could you explain. The wideband has been accurate in the past. Matched up perfect against the dyno wideband several months back. The injector table was changed over a year ago by one of the tuners i have worked with. I assumed he had it correct. The injectors are reworked stock injectors. New flow rate is 42# @ 43.5. I had never noticed the difference between the stock MAF table and my current table.
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Staging Lane
Joined: Mar 2009
Posts: 60
Likes: 0
From: Devils Lake, ND
Thanks 2xLS1. Wondering about the fuel pressure myself. My gauge is under the hood and not visible while driving. May have to reroute the gauge so I can keep an eye on it. I keep the fuel level full or nearly full most of the time so I dont think that is an issue. Tank also has baffles in it.
Thread Starter
Staging Lane
Joined: Mar 2009
Posts: 60
Likes: 0
From: Devils Lake, ND
I went out for a ride this afternoon. I made some changes to the maf table. Made a couple of 1st thru 2nd gear pulls. Should have been better but not enough improvement. Montecarlo, deleting the extra data really improved the data acquisition. Thanks! Gunna have to move my fuel pressure gauge unless someone says i'm totally wrong with my thought of being short of fuel for a short time. (Would be happy with that). RussK, I took a chance that I knew what I was doing and made a couple of pulls locked in 2nd gear but only had the tcc pwm turned on. Not the TCC on unless it was on by default. I don't recall. The log gave some different results that I really don't know what to make of.
Thread Starter
Staging Lane
Joined: Mar 2009
Posts: 60
Likes: 0
From: Devils Lake, ND
Ya I know about the rpm's. Somehow when I was deleting the long and short term fuel trims I managed to delete the rpm pid. Idiot! It is back in my config file again. Basically started from a rolling idle and shifted at 6500rpm's if that helps. Agree about the fuel pressure gauge. I have a pretty good place I can mount it on the back side of the hood scoop. Should have a good view of it from the driver seat. Gunna be awhile before I will have time to mess with it again. Work is calling.
Actron gauge and run it to a standard SW electric
fuel pressure gauge with about 12 ft of wire so I can
have it in the cabin when I want it. The sender output
is also loggable, but I haven't bothered to use it that
way except to test it out. Powered it through a cig
lighter plug so it's all nice and portable.
Thread Starter
Staging Lane
Joined: Mar 2009
Posts: 60
Likes: 0
From: Devils Lake, ND
Had a chance to run the car for a little while tonight. I have moved my fuel pressure gauge to a place on my windshield that I could see. My fuel pressure reads 56# at idle and under normal driving. Made 3 wot pulls. All 3 pulls showed exactly the same. At the hit I drop down to 54# fuel pressure then it moves up to 55# after a second or two. I was positive that I was going to see a large drop in pressure but that is not the case. I realize that my pressure readings are a bit low, but not by much. RussK is correct. My IFR table is off by about 2% if my math is correct. Is this off enough to be an issue? I also watched my voltage gauge during the pulls. It read 13.9 volts and never moved. I'm currently at a loss as to what to look at next. What am I missing?
Post your scan & latest tune. Your fuel pressure is normal and isn't the issue.
And your using 25 bytes when scanning, delete the AFR Error pid from the table as it isn't needed for the AFR Error histogram to function. And replace the dyn cyl air pid with the cyl air mass pid to get your spark histogram & spark knock histograms to work.
Russ Kemp
And your using 25 bytes when scanning, delete the AFR Error pid from the table as it isn't needed for the AFR Error histogram to function. And replace the dyn cyl air pid with the cyl air mass pid to get your spark histogram & spark knock histograms to work.
Russ Kemp
Last edited by Russ K; Sep 8, 2013 at 02:28 PM.