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Thread: Car soft on the launch

  1. #1

    Car soft on the launch

    Hello gents,
    I got a little project i been messing with for a while mostly at the track and tinkering with here and there. Problem is the car wants to launch soft and then roll out. Trying to get this thing to actually get out of the hole at the track. Combo is a TMS 370 with 243 heads and ls6 intake (comp ratio approx 11.5:1) twin S366 turbos, th-400 with circle d 3600 converter with 3.27 rear gears and 275/60/15 tires. I can see in the scan that im maxing the injector (ID1300) out at 5800. ID-2000s on the way. Also Fuel pressure doesn't seem to be increasing accordingly with the boost ref fpr. Maybe maxing pump. But im not going lean yet. Anyways can somebody look at the log and the tune file to see if my timing is about where it needs to be or give any advice. Thanks. Oh and Im running X85 for fuel
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  2. #2
    Any of you experienced tuners mind looking at the file and log?

  3. #3
    Senior Tuner cobaltssoverbooster's Avatar
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    in the injector timing normal table, anywhere you see a 5.55 try bumping that up to about 6.2 with those bigger injectors.
    in the transient fuel tab drop min fuel mg to around .008 or less to remove any issue of hitting a minimum injector pulse limit at idle. this one value tends to hold large injectors open and cause idle fuel issues.
    i didn't convert the egr signal to afr since i didn't have a lot of free time.

    at 3800 rpm and 1.38 g airmass, the ignition event there picked up kr. trying to command 22* and got hit wit about 2.5* kr reduction. which seems correct since you flew off the end of the ignition map and its using the last cells to continue interpolation.
    i would suggest a 50% scale on the injector settings which should bring your airmass calculations lower on the table. you would be able to physically read around 2.4 g but it would plot that at half the airmass on the ecu side.
    50% scale would be actual 1.38 g = ecu .69 g

    you loose table resolution when you do this but if you want to control those ignition events then you need to perform an injector scaling to put the g calculation back inside the table axis. the table axis are not editable on gen 3.
    2000 Ford Mustang - Top Sportsman

  4. #4
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    What I like doing to get up to boost quicker is go to the idle spark advance table in drive and make the values where you are like 2000 rpm and up and .60 cylinder air mass to 1.2 and make the spark set to 0 degrees. That should get those things spooled alot quicker. But you have to go into the Advanced Base spark table and set the min. throttle 100 percent and then set your max speed to like 3 miles per hour or so. That way when it sees 4 mph it will go to your main spark table. Also I wouldn't have nearly that much spark advance in the mid range when your in boost.

  5. #5
    Thanks for the help fellas. The tune is already scaled 25%. I am working on scaling it another 25%. I believe that when I picked up the spark in the log is where I was bumping in. Everything is solid mounted and downpipes are real close to frame. Just a thought. I don't have idle issues yet but I will adjust the transient to see what it does. I know I'll have to redo the VE after. Since I'm maxing out the timing table already and my 2 step was set at 4k I had the timing that high to try and light the turbos off. It worked for the most part but if I need to back it off I will and see what happens. Since I'm already maxing the injectors out I'm switching to id2000s so we will see what she does after the swap. Hopefully the pump pressure stays happy and she doesn't lean out on me.

  6. #6
    Senior Tuner cobaltssoverbooster's Avatar
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    Quote Originally Posted by 87lsttop View Post
    Thanks for the help fellas. The tune is already scaled 25%. I am working on scaling it another 25%. I believe that when I picked up the spark in the log is where I was bumping in. Everything is solid mounted and downpipes are real close to frame. Just a thought. I don't have idle issues yet but I will adjust the transient to see what it does. I know I'll have to redo the VE after. Since I'm maxing out the timing table already and my 2 step was set at 4k I had the timing that high to try and light the turbos off. It worked for the most part but if I need to back it off I will and see what happens. Since I'm already maxing the injectors out I'm switching to id2000s so we will see what she does after the swap. Hopefully the pump pressure stays happy and she doesn't lean out on me.
    i was looking at your injector settings and was like they dont match my id1300 flow rate and seem low. I just didnt put 2 and 2 together that the reduced flow was a scale attempt.
    try shifting that injection normal though. it tends to help with fueling around idle. if the normal is all you change, then you should notice the fuel error go more negative as the burn becomes more efficient and doesnt require as much fuel to make the afr target.
    Last edited by cobaltssoverbooster; 02-08-2020 at 12:45 PM.
    2000 Ford Mustang - Top Sportsman

  7. #7
    Senior Tuner LSxpwrdZ's Avatar
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    Not enough scaling. And technically that is scaled to 75% meaning 75% of the flow rate remains. This isn't enough.

    Start off scaling it 50%. Dial VE table in fully. Ditch the AEM WB and pickup a AFX2 or AFR500v2. Build a real timing table. 20+deg on the bottom axis from 1600 to 4000 is a sure way to bend rods crack pistons or lift the heads. Example timing table for reference only. Different engines/combo's will want different timing at various RPM/Load.

    Timing Table.png
    James Short - [email protected]
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    2020 Camaro 2SS | BTR 230 | GPI CNC Heads | MSD Intake | Rotofab | 2" LT's | Flex Fuel | 638rwhp / 540rwtq
    2002 Camaro | LSX 427 | CID LS7's | Twin GT5088's | Haltech Nexus R5 | RPM TH400

  8. #8
    That's a very smooth spark table. I fooled around with the smoothing on my table after I scaled it another 25% equaling 50total but couldn't get it smooth like that. Any particular reason why the AEM Uego wb I'm using isn't good enough. I've got several wideband, the AEM UEGO, a LC1, a SCG1 and a autometer. All bought back in the day for varipus projects but rarely used.

  9. #9
    The only reason I had that much timing in at the level is because I was testing to see if I could get the car up on the converter and building boost faster on the 2step

  10. #10
    Senior Tuner cobaltssoverbooster's Avatar
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    i should mention that making a 25% change and then making another 25% change from the first change is not the same as taking a straight 50% whack.

    110 lb/hr *.85 = 93.5 lb/hr *.85 = 79.47 lb/hr
    110 lb/hr * .5 = 55 lb/hr

    make sure you performed the later calculation or your changes wont have much effect.
    2000 Ford Mustang - Top Sportsman

  11. #11
    Quote Originally Posted by cobaltssoverbooster View Post
    i should mention that making a 25% change and then making another 25% change from the first change is not the same as taking a straight 50% whack.

    110 lb/hr *.85 = 93.5 lb/hr *.85 = 79.47 lb/hr
    110 lb/hr * .5 = 55 lb/hr

    make sure you performed the later calculation or your changes wont have much effect.
    well crap. Looks like I need to start completely over. Question though. Since my current VE table is somewhat where it needs to be, can I scale the injectors (ID2000s) back the 50% needed and then use the cylinder volume scalar to scale the current settings to the new grams/cyl calculation for the spark table.

  12. #12
    Senior Tuner cobaltssoverbooster's Avatar
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    Yes. Save what you have as a separate file.
    It will take some math because you need to convert the existing back to full scale so you know what its true half equivalent will be. Copy the row in question and paste to its equivalent row in the new 50%.

    From there any gaps can be interpolated using the interpoaltion table features.

    It wont be perfect but it will be pretty close so your not loosing all if your work.

  13. #13
    So if I am understanding correctly I need to descale all my tables that were scaled by.75 including timing and 've. Then cut the ifr timing by .5. Keep my descaled 've but change the volume scalar by .5 also. Input the unscaled ve. Do I need to go back and scale all the tables by .5 or does that volume scalar take care of those tables?Little confused on that one. Thanks cobalt for your help

  14. #14
    Senior Tuner cobaltssoverbooster's Avatar
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    every time you scale your effectively compressing the axis of g/cyl value. your taking the data associated with a high number like 2.0 g/cyl and compressing it down to a lower value. if the scale is 78% then your compressing that 2.0 down to roughly 1.56 g/cyl.

    what i am saying is everything you have now is tuned at that 78% value. You need to convert the axis back to the stock oem equivalent at 100% face value. so if you tuned a different axis value, say 1.7 g/cyl, converting this value back to full face (100% oem) means this data is really calibrated for 2.17 g/cyl.
    100-78=22% reduction of scale. to convert back its simple-- 1.7/.78=2.17g/cyl

    so now you know true face for the axis. when you scale for 50% you are going to shift this true face by 50%. so, 2.17g/cyl *.5= 1.085 g/cyl. this is the new axis value that all your data needs to be moved to.
    so if you have two tune files (1 is the 78% scale and the other is the 50% scale), you go into your 78% file and copy the data associated with 1.7 g/cyl. you go to the 50% file and paste it in the closest cell to 1.085 g/cyl.

    the catch here is when you compress data by 50%, your not going to match up all of your data. what you do is calculate the axis math above in excel. when you get the results, figure out which ones will line up the best with what you have and only transfer those points over. the interpolation feature can bridge the gaps between two known sets of data by using an linear blend technique. if you only have 1 point of know data, it wont work because the tool does not forecast(guess based on previous trends).
    in when your know data ends, you are screwed at that point and can hand blend the table to get close before your forced to tune it back in.

    I am not the best at explaining the calculations and cell reference. hopefully some of this helps out.
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    2000 Ford Mustang - Top Sportsman

  15. #15
    Thanks for the spreadsheet cobalt. That will help. I also have the original tune prior to the scaling .75 so i compared this morning to see what all tables I changed. All the tables I scaled .75 were airflow and spark. Luckily the main table that I was fiddling with was the VE. I really didnt mess with any other tables as the car runs pretty good as is. I did mess with the High Octane spark table quite a bit trying to get the car to get off the line but James said that my timing that I have inputted now is way too high and the table is not smooth enough. So I will need to go ahead and build a timing table that is decently smooth and then scale that table. Or just start with a stock timing table and then remove some timing up top for the boost and then scale that table .50. Of course interpolating between grams that dont line up or manually entering data to smooth the table out as james described in his example. Question is would it be better to start off with a stock LS1 timing table from a camaro or would it be better to start off from a trucks timing table. Ive seen instances where the trucks timing table is way lower but they have all the adders. Any input on that? Again thanks for your help.

  16. #16
    Senior Tuner cobaltssoverbooster's Avatar
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    Im not a good judge for that because i just hand adjuuat timing as i go.

  17. #17
    Senior Tuner LSxpwrdZ's Avatar
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    Quote Originally Posted by 87lsttop View Post
    Thanks for the spreadsheet cobalt. That will help. I also have the original tune prior to the scaling .75 so i compared this morning to see what all tables I changed. All the tables I scaled .75 were airflow and spark. Luckily the main table that I was fiddling with was the VE. I really didnt mess with any other tables as the car runs pretty good as is. I did mess with the High Octane spark table quite a bit trying to get the car to get off the line but James said that my timing that I have inputted now is way too high and the table is not smooth enough. So I will need to go ahead and build a timing table that is decently smooth and then scale that table. Or just start with a stock timing table and then remove some timing up top for the boost and then scale that table .50. Of course interpolating between grams that dont line up or manually entering data to smooth the table out as james described in his example. Question is would it be better to start off with a stock LS1 timing table from a camaro or would it be better to start off from a trucks timing table. Ive seen instances where the trucks timing table is way lower but they have all the adders. Any input on that? Again thanks for your help.
    There isn't going to be a "stock" table you can start with to use mainly because those stock tables flatline at higher g/cyl and weren't ever intended for boost. Building the table from scratch is pretty much necessary for a combo like yours. This is another example of a turbo 370 scaled 50%. The Flex Spark Adder isn't applied to this so this would technically be a pump gas timing map.

    Timing Table.png
    James Short - [email protected]
    Located in Central Kentucky
    ShorTuning
    2020 Camaro 2SS | BTR 230 | GPI CNC Heads | MSD Intake | Rotofab | 2" LT's | Flex Fuel | 638rwhp / 540rwtq
    2002 Camaro | LSX 427 | CID LS7's | Twin GT5088's | Haltech Nexus R5 | RPM TH400

  18. #18
    Thanks for sharing that James. I will post my timing table that I have scaled in the morning. One thing I am confused about is in the lower rpms but the higher g/cyl where the cars obviously never going to be operating what do you do with those numbers. i noticed in your example they go pretty negative. On my stock file it was still relatively lower numbers in this are. A lot of the tunes that I have seen from even shops show a constant number all the way through. Im guessing they are leaving a bit of power on the table as they dont ramp the timing back in after peak torque.

  19. #19
    Ok Here is the full tune scaled .50. I tried to view the timing table James posted and smooth it like his is. Please let me know if the timing seems a little too aggressive. I have a week before I will be able to test this on the car again so i got a little time to come up with a baseline.
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  20. #20
    Senior Tuner kingtal0n's Avatar
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    In my software theres a table called "afr advance" and I was able to use that to get the necessary timing adjustments without scaling my tune at all, but I am only running 18~psi max now on 93

    whatafradvdoes.jpg

    I'm just trying to help by pointing out that there are a bunch of other ways to adjust timing as needed, besides the main maxed table