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So let me start by saying a few words. I do not take anyone spending time to help me lightly. Everyone’s time is precious we all has so little. I surely know this car I built from the ground up in 2005 and tuned it with a much smaller cam and ls6 intake. My wife and I own and operate a horse boarding facility and work full-time jobs. I fully understand time is precious! I have been reading as fast I can through all the docs etc and trying to learn this all over again. “DRINKING FROM THE FIRE HOSE” This time even understand it better with this MAX effort stock bottom end setup that is not forgiving. I’m sure I can find a speed shop to tune this car perfectly and it’s not a money issue. It’s a I love doing this stuff but limited time and hot rodding to me is doing it yourself and learning. Anyone can write a check for a hot rod, every time I go to the track there are 10 hellcats to every built car… I also have not been on LS1Tech in some time, it’s awesome to see the community come together to lend each other a hand! I hope to pay some back!
So on to some tech things:
@LilJay THANK YOU for taking the time to edit my tune.
-- I was looking over the changes you made making sure I understand why you made them instead of just loading it in and turning the key.
--I see the change you made to disable the MAF. I though unplugging it would disable assuming the PCM still uses for some sort of corrections.
--STIF in the log playback I’m seeing .6g/s. Assuming that is a big deal? Not seeing 6g/s but .6g/s
--IAC Desired vs Commanded I see a difference of 10 is that what we are talking about being IAC fully closed? To much air. 185 vs 175
--Alternator not charging assuming you are looking at 12v not running and then see it go to 13.1 should be 13.8v I would think. Car does have an underdrive pully and a brand-new alternator from like 2008 when I purchased it new.
@ txh0tb0i972 THANK YOU for the injector data I will compare that to what the Texas Speed provide higher in the thread. Also, the offer to look at the setup real time etc!
Feel like I’m still missing things here but here is my next crack at it. Today and tomorrow are challenging days at real job. Hope I get an hour or two tomorrow to spend shop time… Long weekend coming up so there will be shop time!
The iat sensor is not present i have a resistor in its place so it's always 39degrees... Will add pid and log hopefully tomorrow...
Rossler Max build 4l60e yank 3600 Ford 9". This setup won't break it. I know stall is a bit small
I just noticed you are using an aeromotive regulator. Does this car have a return style fuel system?
In regards to your question with unplugging the MAF to force speed density. Yes you can unplug it if it's a 3 wire MAF with an external IAT. That 100mm MAF has the IAT integrated into the MAF, if you unplug it, you unplug the IAT sensor which screws up the VE calculation because temperature is a very important part of the equation. Are you using a external IAT like the F body's use? Personally I always fail the MAF in the tune. It's like most things, there is more than one way to do it.
Yes, an IAT is essential, especially with your wild cam. Air density (and therefore your A/F ratio) varies by 14% between 30F and 100F according to this chart: https://www.engineeringtoolbox.com/a...ght-d_600.html
Since most of my setups have been MAF-less and I want to avoid heat-soak, I place the IAC either in the cold-air box or behind a headlight. This gives an accurate reading of the air that will actually enter under high throttle.
Sorry I forgot the GM part # for a stand-alone IAT, but its cheap and only needs two wires going the the ECM/PCM.
That was the original reason for removing the IAT sensor. It was getting heat soaked at the track coming through the staging lanes. I will work to get that re-enabled. Like I figured, I'm not going to get in my shop this evening. I hope to have an update here tomorrow with a log etc. Thanks all!
The car has all braided line fuel system with a return line.
--Thought the TB was closed with screw but it was not. Now its closed!
--Fuel pressure is solid 59LB no vacuum controls
--Loaded the tune file from Liljay
--Scanned till operating temp
--Still need to do some wiring to get the IAT back in play
Car idled was almost perfect definitely can be reduced RPM after further idle tuning. Did all this quick just to get a log so i know more to do here... I'm looking at the log now as im posting it up...
If its completely closed something is up, I would open it up some,
the odd part is that STIT is still showing to pull 2-3g/s keeping your desired airflow at about 3.5 gs.
You can try to adjust your VE table, to try and reach 14.7 afr or you can do the following.
I would suggest logging TPS Voltage, I would then recommend, logging and turn the tb screw to about .50-.76V. once you're somewhere in between there, do the TPS RESET deal.
You should see your TPS % is going to be about .04% or so.
After that i would try to Log again, fix your VE err and see where you stand.
Last edited by txh0tb0i972; 06-29-2023 at 03:37 PM.
It's interesting that the STIT is that negative and the IAC counts are what they are. I'd leave the T/B alone for the time being.
Also, start logging your wideband in Lambda and forget about AFR.
This probably sounds trivial but, when you add the Lambda WB02, add it under the commanded EQ PID. It is a lot easier if they are next to each other. That way you can look at both at a quick glance compared to one being and the top and the other being at the bottom.
It's still rich at idle. Start logging Lambda, then we can start using the commanded EQ Err pid.
It's interesting that the STIT is that negative and the IAC counts are what they are. I'd leave the T/B alone for the time being.
Also, start logging your wideband in Lambda and forget about AFR.
This probably sounds trivial but, when you add the Lambda WB02, add it under the commanded EQ PID. It is a lot easier if they are next to each other. That way you can look at both at a quick glance compared to one being and the top and the other being at the bottom.
It's still rich at idle. Start logging Lambda, then we can start using the commanded EQ Err pid.
I’m thinking once that adjustment is made it should correct that iac
That cam is not going to idle at 1.0. The overlap of that cam is going to trick the sensor into thinking it's lean due to overlap of the cam. That's the point of running open loop at idle so the factory 02 sensors can't add any fuel.
The VE under 1200 is going to a lot less because the cam is inefficient at that low of engine speed.
I added and moved around the pids created an EQ Error graph.
--Log1 is just new PIDS
--Log2 is lowered VE 10% 400-1200 rpm
-Log3 is Commanded timing to watch MAP. Seemed like it liked right around 24 degrees giving the lowest MAP reading high 58ish
Car was definitely hanging idle when i goosed the throttle today. Seeming like yesterday i was reposing fairly well... I'm sure there is story in the log I'm not following...
When a cam has overlap, there is a time where the intake valve is just open while the exhaust valve is just closing. This means a bit of your intake mixture (oxygen and fuel) does right out to the exhaust and past the O2 sensor. The O2 sensor measures "unused" oxygen and it a result it will show a very lean value due to this "unused" oxygen. So even if the combustion would read a perfect 14.7/1 ratio, it will read very lean with an overlapping cam.
Now it does seems that such engines run better with e.g. a 13/1 mixture, meaning that if your O2 sensor reads 14.7/1, you might actually be at 13/1.
As @LilJayV10 suggests, it is best to run open loop on overlap-cammed engine as any closed-loop "corrections" are not useful.
When you post a log, post the corresponding tune. That way we can see the effects of what you changed. To make it easier to keep track of, I put JH1, JH2 and so on with each tune revision and the same with the datalog. It's easier to keep track of and if you need to go back and reference a previous log, you know what tune goes with it.
I am still a little perplexed by the BRAF unless you have a vacuum leak, there is something off with the injector data or an issue with the TB.
Speaking of injector data, I didn't see the flow rate table listed in the data. Either I completely missed or I'm an idiot. Either are possible.
I used a
calculator to get the flow rate it was a spreadsheet I can attach it maybe that is also an issue... The flow rate table was not provided with the injector purchase... As far as an intake leak, all new seals on that intake and was maticulus during the install. I could try to seal the rear ports instead of connecting to brake booster and the vacume that goes to the heating controls if the car. Could the valve cover breather be causing some air flow back into the TB?
06-27-2023, 07:03 PM
