New tuner... new tune!

[Brad Campbell]

I have been playing around with my newly built turbo camaro. Its a 8.75:1 383 ls1 with sd 60 pound injectors. I'll post the cam specs later if anyone cares, but it's around 234 236 with 595 and 605 lift. Anyway I've been trying to work on the VE map, and it seems to be going in the right direction. I was hoping someone might have some input either good or bad. I have yet to dip into boost at all. Most anything I didn't have to change is stock, and the rest is just adjustments to tune in open loop.

Thanks!

[Ben Charles]

How does it idle? Our injector offset table and a few other fuel tables are identical. What fuel pressure you running?

[Brad Campbell]

I'm at 55 pounds for fuel pressure. It starts and idles perfect unless my iat sensor is heat soaked.

[Nitroused383]

I would match your power enrichment table and boost enrichment tables up as boost enrichment does not respond right away. You won't be in boost until a certain rpm anyways so to keep things crisp / responsive stay around 1.0 up until about 2000 rpm and than taper your commanded AFR until you hit your boost threshold. Before you get into any boost I would suggest you double the 315kpa row and vertically interpolate the entire table down to 100 kpa (see pic below). The boosted setups I've tuned hit well over 100 VE by 105 + kpa. Some N/A setups have been around 105-110. I would rather it be safely rich when you hit boost rather than dangerously lean.

All your fuel injector info looks to be properly setup, good job on that Ben I recommend you copy his offset table. Running a SD tune can be a bit tricky as the IAT sensor plays a big role in fueling, heat soak really throws things off. A bit of playing around with the Airflow > General > Cylinder Charge Temp > Bias table can help a great deal. The higher you raise the numbers up to 1.0 the more the fueling is biased towards the coolant temp, thus being a good idea to have a higher bias towards coolant temp with less engine airflow (lb/min). Lower numbers towards 0 bias fueling to the IAT sensor. I included a bias table I've had good luck with, I've taken advice from other very knowledgable tuners on this board and set the 0lb min cell to 1.0. At 0 air speed the air would heat up to the same temp as the coolant, if this makes sense, more air speed less heating, less bias towards coolant.

While scanning try to include less than 24 Parameters, anything over 24 lowers the scan resolution. I would delete your short / long term fuel trims as you do not need those. Delete the MAP (SAE) parameter you're scanning as it can cause some issues scanning two map PID's. I would add in burst knock retard and injector duty cycle %. You may also want to lower your main timing, it looks like you're around 19 degrees under boost, I would start around 13-15 degrees just to be safe for now. You will want to get your burst knock setup too as it will be pulling timing, do not completely 0 it out as it does a good job of prevent real knock when setup correctly. It is located under Spark > Retard > Burst knock retard > enable delta cyl air. I would set all your values above 2000 rpm to .100 or so and go from there, if you're seeing a large change in cylinder airmass it will pull a few degrees of timing to prevent knock, if it's pulling too much timing just multiply by 25% until you're liking.

Your startup and afterstart enrichment tables will really help with hot starts. I've included a few pictures which I think should help startup when heat soaked. Good luck and if you have any issues be sure to post up.

[Brad Campbell]

Thanks for the tips. I will be working with all those items as I move forward. I was hoping to nail the driveability are of my VE map down, so I have some confidence, then move on to some of the other items you discussed. I'm not too disappointed as the car starts just fine and drives well. Good news is I'm very patient and view the tuning aspect as a project much like building the car was. Thanks again!

[Ben Charles]

Nitrous I copied the Offset table, plan to go mess with my car here shortly.

[Nitroused383]

Brad could you post up your configuration file you're using for the scanner. Sounds good Ben, those values will help!

[Brad Campbell]

Here it is. I made a new copy of my tune with the suggested changes. I know I'll need to make quite a few VE changes once I enable the charge temp. Thanks again for any suggestions.

-Brad

[Rinkrat456]

Please document and post everything you can during your quest to tune everything.

Subscribed to this one! Carry on fellas.

[Nitroused383]

I changed a few things on your scanner config to help it be more informative, try it out and see if you like it. Histogram #7 I added a filter to only record AFR Error % over 2% TPS, this keeps your deceleration error % from getting mixed in with the data. Histogram #8 is your decel AFR Error % basically only records less than 2% TPS. I also changed the cell counts to 50 as you will pick up a lot of random hits that are not necessarily accurate counts. Also when sorting through your histograms be sure to right click a cell and click "load all data". You may have known this, but quite a few people do not load all their log data. Be sure to use "A" for average values too, as the Max, Min and Last values are not what you want to use for populating your VE tables.

I setup a boost PID which is always kind of handy so you're not trying to convert KPA to boost. You may have to do a little work for your 3 bar map sensor as I'm not sure what the PID# is for a 3 bar. The function for the 2 bar PID is ([PID.2333]-[PID.2340])*.145

PID.2333 is for a 2 bar sensor so just change it to the 3 bar PID. Here are some pics included to help explain, do not add any values to the sensor or units as the beta version has a glitch not allowing it to work correctly. I have reported the issue and they are aware of it.

[Brad Campbell]

Great! Just a few questions though...

Does the decel matter if I have it disabled? I think what you did will work great to eliminate error when passing from higher manifold pressures and engine speeds towards idle on shifts and coasts to stop.

I will have to look into the data conditioning. I have seen other people discussing their methods, but was not sure how to create the logic. Increased cell counts will be helpful. Right now my process is to shut the car down. Replay the log file to refresh the cells, and click between the average, the count, and the editor to adjust my map. I also created a spreadsheet that I can paste all the log info into, and adjust the target cell count to exponentially filter the averaged data. I added a multiplier to so I could cut back the final corrections and eliminate overshoot. It seemed to be working all right, but I quickly noticed that there is more logic I wanted to add. I have just decided to do it long hand if you will.

For the boost sensor PID does the 3bar pid that's pre loaded work correctly? I am using the older style rectangular gm map sensor? Can I mod this to work with kpa? I'm a systems engineer for an industrial engine control company, and I really do feel most at home viewing manifold pressure in kpa?

Thanks for all the input, and as the previous user asked I'll try and keep my progress documented here. Also... while we are at it what are all your names.

Thanks!

-Brad

[Brad Campbell]

Oh, and naturally i'm not running the beta... is it someting I should be changing to for added functionality?

[Nitroused383]

There are a few nice features I like in the beta version, I feel they benefit manual transmissions with their rolling idle tables for one. Most of the updates though benefit the 05+ operating systems. I would say it's a wash really lol. I use two seperate TPS % filters because coasting down can transistion data into your cruising cells and once you average it all together it's not as accurate without filters. Just a lot simplier for me to copy and paste idle / coast cells seperately from light cruising cells, especially with a manual.

I'm not sure if you've watched the auto tune demo http://www.thetuningdoctor.com/HPTun.../copypaste.swf
To populate your cells just right click the cells on the histogram page and click load data, no need to replay the entire file. I like to use the copy / paste features for driveability cells. I almost always multiply by % - half to avoid over shooting. It's quick and easy but everyone has their perfered method. Obviously this isn't your 1st time tuning as it appears you know what you're doing. With the WOT stuff I just look at the charts and do that stuff manually.

I would assume the preloaded 3 bar pid would work correctly as long as you enter the right map sensor linear and offset values. This is located under engine diag > airflow > map sensor. I do not know the correct values for your 3 bar map, with the engine off and the key in the run position what KPA is your map sensor reading? You may need to tweak the offset value to read the correct kpa for your elevation (99-101 sea level?). I'm at 2300' and my stock sensor would read 94-95 kpa. You do not have to use the Boost PID as your map sensor will dispaly in kpa naturally.

Jason

[Brad Campbell]

Thanks. I was under the impression that the loaded calibration for the map sensor was correct. I think my sensor reads 105kpa and I'm within 10 feet of sea level. I can tweak with it to get it on the money, but with standard error my assumption was it would be fine. Manifold pressure readings underway are realistic as well. I do have to switch to the 3 bar pid though as the stock manifold pressure value will not read above 1atm? I was just playing with the conditioning on the cells, and the faster "load all data" feature. All that stuff is really slick. Thanks for pointing it out. Hopefully we get some nicer weather later this week, and I can get back out for some more tweaking. I have had this thing up and running for almost a month now, and I've yet to get on it. I guess it sucks to be intelligently responsible. My bank account will thank me later.

Thanks again for the great advice. Hopefully others are learning just as much!

-Brad

[DrLoch]

Brad, Jason, this is really good info. I'm in the process of tuning my LT1 / 411 combo in a 94 Impala SS which is almost identical to Ben Charles' setup. I've been watching for posts like this that will help stream line my tuning efforts when I'm able to get it moving down the road. So far I've on been working on the idle portion as the car didn't have wheels or tire until last week.

Dennis

[Brad Campbell]

So I just made a quick graph of the min, mean, and max values of the delphi 3 bar map sensors. It basically looks like you can be +/- 5kpa at around 1bar absolute. This would suggest that people should use the offset to dial in their specific sensor at their elevation. Is there truth to this? I'm within the tolerance so I didn't really care, but as long as the sensors specific error trends in the same direction this should help be closer?

[Nitroused383]

Here is some good info about offset and linear values. This is specefic to the 2 bar sensor but if you have the part # for the 3 bar sensor maybe powerandsignal has a blueprint on it to calculate the correct values. http://www.hptuners.com/forum/showth...powerandsignal

On the config I posted I deleted the MAF PID and the MAP (SAE) Pid. Scanning both of these with the 3 bar PID will cause screwy results and not read above 1 bar. If you don't have the beta I dont know if you can open the config or not though.

[Ben Charles]

I want to add to the Map values. My Stock GM LT1 1 bar map read 101kpa, key on.

My aftermarket 2 bar doesn't show anything with key on, but when stalling shows 95, changed the Sensor offset from 10.XX (factory 2 bar) to 8.01 and it actually lowered the value to around 93 I believe. I then changed it to 11.99 and It seems to be around 95 still? I need to play with this more and get it back to 101kpa I believe.

What exactly does the Linear value do? Instead of 200 I would think that needs to be 210?

[Brad Campbell]

Great! Did some quick tweaking tonight. Won't be running the car cause it's raining out, but I made a new tune file with the bias enabled. I made a spreadsheet today to convert the air density from the IAT only temp to the bias temp based upon the bias table and an iat of 85 f and a ect of 185. Interesting to see how that works out, but it helps to auto adjust the ve based on the change in calculated density.

I also tweaked my scanner config cause I can't open yours and dropped both my high and low timing maps down so the high is out at 13 and the low is out at 10.

Another questions I had was how do I set up the burst knock. It's the stock value right now so it should be pulling up to 2 degrees I think?

-Brad

[Brad Campbell]

Ben,

It's the full range value of the sensor @ 5 volts. Should be around 210 I would think as well. I was looking at a spec sheet and a Delphi 2 bar is showing 204 205.